I don't think I have ever come across a more concise, succinct and clear set of teaching videos. A week ago I knew next to nothing about cars and I have been watching youtube videos non-stop for a week. Your videos are the only ones I've come across that a) take this logical, diagnostic approach to fixing cars and b) recognise that the ECU is central to how cars now work and it therefore needs to be at the centre of any auto mechanic's thought process. Thanks for putting in the time.
My volvo 940 has egr, pulse air, & pcv systems .. My mechanic who has managed my car for 6 yrs has caused so many problems .. after much frustration with high idle, water pump they put in that leaked ever since they put it in, radiator replacement, misdiagnosis, they don't dx anything, I learned every thing about my car, and I have it running well, found both pulse air valves dried with carbon replaced them, cleaned all connection with elect contact, fixed throttle position sensor as they must have messed with the screw adjustment so no click, cleaned throttle body all small holes as well, cleaned the egr metal pipe intake like u said it was clogged, the air box thermostat was stuck in hot position only, replaced thermostat that was stuck, pcv system was disconnected and the plastic filter clogged and hard, replaced that, replaced relays, applied new heat sink to the ignition module as it needed it, replaced fuses, water pump, timing belt seals, spark plugs, cleaned injectors and replaced the microfilters inside that were crumbled into pieces, it sounds good now, idle seems perfect, I have to adust the kickdown cable little more, they had put a loose air filter in my car that didn't fit my air box a lot of dirt getting in, cleaned my MAF sensor, and getting ready to remove the egr to clean the openings,but since the intake egr pipe was clogged like u said what caused all these issues,was it the pcv .. why is their 3 system like this to manage. I'm a 66 yr old woman who up until this year only went to mechanics, and relied on them to know what they were doing but they seem to have no clue about lean or rich codes, didnt know how to do my codes.. now I'm having to replace the power steering line they put in So I paid them so much money over he years . Seems like they would have done the fuel filter, put the right air filter in or made some effort to check the pcv etc..
Man you are good. Thanks for explaining all of this with great logic. I haven't seen one other video that takes the time that you do to make sure everything is understood so well. Great job teaching. All ford 150 owners from 97-02 should watch this video series.
This is great but I must be doing something wrong. I tested everything (I think). I have replaced the EGR, vacuum solenoid (aftermarket), DPFE sensor (OEM), checked the electrical output, cleaned the throttle body, intake, EGR tube etc. The car is running very smooth but I keep throwing a p0401 code. This is a 1997 ford f150 w/4.6 liter 4x4. Any further recommendations would be greatly appreciated. My fuel trims look fine as well.
@@SchrodingersBox well im an idiot. i had the DPFE hoses switched...I checked it like three times but was only looking at hose length rather than the size of the connection on the DPFE and the EGR tube. So dumb...alas that was my problem. thanks for the videos. i learned a lot that i will probably use later. If you ever do things specializings in subaru wrx's (2003 :-)) that would be great.
when you say your a scientist, does mean your a high grade science teacher?? its just you have a natural ability for teaching a novice overall demographic about engine components is all... you really are a great teacher, THE BEST on YOUTUTBE!!!
Great video series. I repair used cars, boss told me car had some kind of code for exhaust flow and to check exhaust for leaks and weld it if need be. Code was p0401.... fun times, still haven't been given chance to diagnose it further after telling him it has nothing to do with exhaust leaks.
It's funny you should say something about hooking up a system to test while driving because the other day our computer crashed and I actually had to rig a way to test control and activation of the solenoid. We made a plug to plug into the connector and ran a wire into the car that we could hook the meter to. Man it looked funny and we had a code or 2 pop up as a result but it worked beautifully. That's that diagnostic mindset of making sure to test every component thoroughly lol. Great vid Matt.
I have a 1999 Ford F-150 XLT, 5.4 Liter, Sport 4x4. I must say I am wheelchair bound, partial paraplegic, and for the most part and trying to work on my truck is difficult at best. It started showing a PO401 error code not long back. Well the first thing checked was of course the EGR valve and trying a vacuum test, etc. it was bad. I even tried to clean it out but to no avail. Well after replacing the EGR valve about three weeks went by and that code popped back up. So with help from a friend we checked the vacuum lines and replaced all of the bad rubber vacuum lines which could be found no matter where they were located. Again, that cured the problem for another month. The code pops back up. Well with help he just happened to stumble on a broken green vacuum line which runs from the electronic volume vacuum flow solenoid to the top of the EGR valve as you showed it on your video above with it sitting on the cowl panel. So we replaced that line and I instructed him on how to do a simple vacuum test from the electronic volume vacuum flow solenoid to the EGR valve to see if the engine would stall out while running. Nope, nothing happened. It ran pretty and smooth at 650 to 700 rpms. Now back in the autumn the intake manifold was somewhat cleaned but from looking dead on inside but it didn't really need to be cleaned nor was it removed from the manifold so I have no idea if the two small EGR tunnels are plugged up or even just partly plugged up. Based upon how clean the other tunnel seemed to be right there at the EGR valve seemed to be when the factory EGR valve was removed, it was cleaned out as best as possible in loving care with little to show for the effort. The factory EGR valve was cleaned as well with hopes I can continue to use it with little to show for the effort but still even that did not save the day. Another friend hooked up his professional code checker and the entire engine checked out perfect between long extended times when the PO401 error code popped up so that just adds to the confusion. Just yesterday coming home from the hospital I noticed the check engine light came back on and guess what the code was? So I started making calls to almost every local mechanic and every one of them agreed, in these words, that there is a 95% chance it is the original factory metallic DPFE back flow solenoid. Now, granted I have no way to check that electronic volume vacuum flow solenoid and I also have no way of checking out the DPFE back flow solenoid, nor do I have any way to check the remaining rigid plastic green, red, and yellow vacuum lines to see if they are leaking. I must also admit that very recently I had to get the exhaust manifold leak repaired at quite some cost to me but I give many thanks to God that each broken exhaust manifold bolt, all three of them, were broken on top of the exhaust manifold. I am running out of ideas and to be honest I have not ever had this much of an issue with a EGR error code before on any vehicle I had owned up until now. Can you please provide me with any possible hints on something which I may be able to try? From what I am now hearing from so many professional mechanics now that I have asked in the surrounding local area, it may actually come down to biting the bullet and actually changing out that factory metallic DPFE back flow solenoid which everyone is saying has given so much of an issue in the past and was why Ford went to the plastic DPFE back flow solenoid.
You guys in the States get the best wiring diagrams in the world! You don't know how luck you are! Over here in the UK you get black lines going to black outlined boxes lol. If we're lucky we'll get told what colour the wires are! :-) Where do you guys get wiring diagrams with '5v ref', 'control wire' etc, you are so lucky!
@@SchrodingersBox I thought maybe you subscribed to a vehicle data site, ondemand5, Mitchells etc. In the Uk biggest ones are Aldata, Autodata, Haynes pro and none of them mention the 5v reference circuit, control wires etc.Especially within a pcm or something similar. I do know how to figure out these things for myself as i'm on a vehicle tech course, but for quickness it's really handy to have everything on a good data subscription site, rather than ploughing the vast void that is Google.
No- being a Do It Yourselfer I can't really justify a subscription to a service. If I did, I'd use Mitchell- I like their diagrams better than Alldata.
Excellent video. I really look forward to this style where you explain the concept and then show how it works on an actual car or track down a fault. I was curious about how you did the testing on the signal integrity to the vacuum solenoid. Why not leave the solenoid hooked up and backprobe on the ground side measuring the voltage. That way the computer sees the load it is expecting and you get a functional test of how well the computer can pull the line low with the load in place. Keep up the good work and can't wait for part 3.
Steve U That would have been a better way to do the testing and in fact was my first preference, however the problem was I just didn't have enough clearance when the valve was connected to ensure the backprobes didn't touch themselves or more likely, a ground. There was just way too much concern of shorting the power to ground because of the design of this vehicle and it would almost guaranteed fry the EGR driver in the PCM. The vehicle I will use for Part 3 with the electronic EGR is much friendlier location and I will be able to do the testing the way you describe.
Excellent Matt well instructed. The egr harness signal interigity test , while testing on ohms , interesting. As for the pos. side of the circuit tested unloaded can be misleading if you suspect an input to the egr fault. My RUclips drivability instructor has proven the value in the loaded test for voltage whenever possible to detect an inability to carry currant . I only do loaded voltage test. Fantastic Matt look forward to part trois
I'm behind in checking your videos... when you checked the solenoid with a vacuum pump, vacuum would have held if you had attached the pump to the "manifold vacuum side" of the solenoid. The EGR side "drops" vacuum because of the "air bleed" (part of the solenoid) that allows the component (EGR, diverter valve etc) to close when the solenoid is not energized. Disconnecting the solenoid to "test" the ground can / will set a fault code, since the PCM no longer "sees" the voltage going through the coil / solenoid. On VW's it'll set "open or short to ground codes " (for whatever the solenoid controls). As always, lots of good info and the comments below the video also provide good reading!
If I am understanding this ........If I had a p0401 (insufficient flow) along with p0171 and p0174 (bank 1 and 2 lean) I would want to inspect for a vacuum leak that is causing weak vacuum in the EGR. If I was stuck open it would possibly cause lean codes but the insufficient flow would not be an issue if I am following you correctly. Would a vacuum leak large enough to cause a lean code hinder the vacuum strength in the EGR? Haven't had a chance to dig in yet, I'm just trying to put my thoughts in the right direction.Thanks for the lesson!
I suppose its possible. If I had both codes, I would start with P0401 first by checking the EGR if it is stuck open or not. If it is, that is likely the source of both codes. If however the EGR is closed at idle, I would start with a fuel trim analysis first to determine cause of lean condition first.
@@SchrodingersBox Thanks for the reply. My first stop will be to see if I can manually manipulate the EGR with my hand held vacuum pump. If I can I will work backwards from there to the vacuum solenoid. If I can't I will pull the valve and check for carbon build up. Again, thanks for the great explanation!
Yes the egr intake pipe was clogged at the top like u said but I can't get the egr off to clean it, I sprayed MAF sensor cleaner inside the valve, and cleaned the electrical connections but Im now worried that I could have damaged the diaphragm with cleaner and cannot get egr off
I know with GM OBD1 you can get the car into diagnostic mode by shorting pins on the ALDL which does exactly what you had there with the air pump coming on etc with key on engine off. It's a little easier to troubleshoot since that mode basically commands "on" components that would normally be inaccessible without a scan tool and you can leave parts in place. Most OBD1 and OBD2 cars have a "Field Service Enable" pin that can make the magic happen but you have to know how to get the car into that mode without a scan tool. Not impossible but a little tougher.
I’m sure you’ve figured this out by now, but, had you’d put a T pin on the secondary “power” wire with the plug plugged in, you could use a test light to use as a ground side switch. Basically, hook the yes light on the T pin and then touch the T pin with the test light thus grounding the power feed.
Hello Matt, my name is Peter, I have 2006 Suzuki Grand Vitara 2.7. I've had rough idling and hard engine start especially when the car is already warm, basically I have to crank it a lot to get it going when the problem is present. I get the P0401 code for insufficient exhaust gas flow. So with a mechanic we took apart everything on top of the engine and cleaned the EGR passage and the pipe that goes to the exhaust manifold, cleaned throttle body and so on... I am thinking now if we might have missed something when we were doing the job. I can't remember if we cleaned the lower and upper joints of the pipe that gets the exhaust gas to the EGR,(we did clean the pipe itself, not sure if we cleaned the continuation of that pipe where it connects on the upper and lower side) also where ever the EGR itself gets connected to, I am not sure we looked and cleaned that too ( we just cleaned the two EGR holes where the valve is) Just thinking of what we might have missed because now, 300 miles later after the cleaning, I got that rough idling again with the exact same code and symptoms, so I am wondering if we might have missed on a dirty clogged part on the system or there might be something else. What would you suggest me to do and check for based on the symptoms I am getting and also having in mind that it happens, then is stops in few days and then comes back like 500 miles later, been like that for the last 8k miles... The mechanic doesn't have the sucking tool, but we don't think the EGR valve is faulty because most of the times I don't have the issue, I just think that we missed to clean a spot where there is a carbon build up, what do you think ?
What is your eve commanded position? what is the fuel trim adjustment with manual EGR operation? What is the duty cycle? There is no information that can be used to make a diagnosis.
Unfortunately I don't know or understand any of those questions, nor I know where to find them, I uploaded the full service manual of my car here, upstore.net/DdL3sgL would that give you the answers needed ?
Well I learned an expensive lesson today, Do not try to take your EGR tube off down at the exhaust manifold just to check if it is blocked. The thread got all messed up while I was undoing it on both the flange nut and the adaptor going into the manifold, then I could not get into it to undo the adaptor so I had to pull the whole exhaust manifold off and then while I was trying to undo it the the whole thing snapped off. So now I have to buy a complete new manifold with the EGR pipe and I can only get one from the US and I live in the Philippines now from Australia so all up it cost me $280 US and my car will be off the road for 2 weeks or more waiting for the parts to arrive. And the worst part is that the pipes where all nice and clean. I then carried on with my testing and found the problem was the EGR solenoid that was not working so it was a pity I did not test that first before I tested the EGR valve vacuum can and then decided to take the pipe off to check it was not blocked at the manifold while I already had the EGR off. I should have just blown compressed air down there first to check if it was clear or even used a piece of wire down the tube.
@@SchrodingersBox Another RUclipsr suggests checking the manifold end of the tube for blockages so I thought I would just check it while I had the chance. I can't run it now until I get all my parts but I hope the new solenoid fix's my P401 code and check engine light I keep getting .
Matt, what I did not understand is that when you were testing the power and ground wire, you had constant power there, you said it was ground side switched, but you measured ground continuity. If the ground circuit from PCM is open, how would you get continuity and resistance. Would appreciate if you explain this tiny detail. Thanks Matt for your videos!
This is explained in detail in my basic electrical series but there actually isn’t constant power because the pulsewidth modulation is too fast to see the ground side control.
Hello, I have a 2018 impreza . Standard boxer engine 2.0. My car has direct inject. I am very concerned about carbon build up due to this fact. I have already installed a catch can on the p c v . I have concerns about the e g r sending gasses into my intake . I don’t have any fresh fuel continuity cleaning the back of my valves . Please share any thoughts on how to combat this issue. I am considering the ole e g r delete not for racing but to stop recirculating crap into my intake . Any suggestions or knowledge you can share is greatly appreciated . On another note you are playing on your own field. Definitely received training above and beyond most I see .. 👍
Well- in a way... when throttle is open it may command EGR open depending on conditions but there isn't a direct link between EGR and TPS- it's more of an indirect effect.
You know Matt I was thinking. When we open valves at idle to see if the car "dies", does it die from and extreme lean condition or do you think it dies because we introduce a large amount of inert gas that it can't combust? I was eating my dinner and just thinking of that actually.. I don't ever recall looking at STFT while opening the valve and having the engine running rough to see what it does... hmmmm. Sounds like time for an experiment! Also just a thought on the meter and the test. I guess I have never tested for computer control using an Ohm meter, any how not to be Debbie downer but the meter was set on the 20k setting so when it dropped to 5.xx ohms that actually wasn't ground was it? Any how just a thought, next time when you are checking to see what side of the solenoid is power load it a little (ie. test light) other wise both sides will show 12v + using a high impedance dvom. Just a couple thoughts. I'd love to discuss this a little further if you like. PM me if you want to chat a bit. Got a million things on my mind all the time haha. See u in part III!
Yeah I will cover in Part 3 but trustme, even just a little EGR and the O2's voltage tanks and STFT adjusts lean. You would expect rich response but it is indeed very lean. I am not sure the reason yet- I agree, inert product should lean the sensor. It could also be a MAP thing but even so, the MAP would add fuel and O2’s should show rich then. Still working on that one lol.
DE Nichols These experiments could end up in the Cern particle accelerator at the sub atomic level. Where did I leave my final year chemistry manual ? Have they scrapped the periodic table yet?
on my 95 lexus sc400 v8 the engine has a rough idle and sputters. i have a check engine light on. when i press the gas the rpms on the tach go in the wrong direction. they go down instead of up like a vacuum leak or something. so far i put fresh gas and cleaned the throttle body out which was very dirty with carbon build up. that cleared the check engine light however after 30 minutes it came back. when i smoke tested the engine i did have small leak from what appears to be the gasket of the egr valve. can the egr valve and gasket this be causing my issue?
Hmm... It may also be the case that the PCM won't activate EGR controls until it's in closed loop. If you think about it, the primary concern of the PCM is to get the engine into closed loop as quickly as possible. Enabling the EGR system lowers combustion temperatures, and in theory, would delay the engine warming up. Just a thought, though; not sure if it's accurate.
Man, I do believe I failed to mention that in the video. You are correct, EGR is in closed loop, it is one of the times EGR is bypassed and I failed to mention it. Nice catch!
I performed the vacuum test on the EGR valve. When I initially tried it, I would get to about 20lbs and the engine would nearly die but stay running, hardly. The second time I vacuum tested (with car still running from previous test, and releasing vacuum to return to normal idle), I did get the car to die with a few hard pumps (of the hand operated vacuum pump like the one you used) to roughly 15lbs. My questions being.. Is more than 20lbs of vacuum required to kill the engine, i saw you used about 10lbs and the engine dies on your end. Would this be a clogged EGR Valve, or clogged EGR ports. Also if I find the EGR valve is clogged is it a good indication that the ports leading into the manifold are clogged as well and should be cleaned for good measure, is there a test? Refering to a 92 Accord 2.2 having 4 EGR ports on the intake manifold. Thank you for the videos you have posted thus far, exactly what I was looking for rather than getting balls deep into parts swapping. Cheers, Chuck
Update: Last night while my vehicle was sputtering after being warm, I pulled over and I unplugged the vacuum line to the EGR (in attempts to narrow down the cause of the hesitation. I was greeted with a check engine light as expected and the vehicle wasn't engaging EGR so it was running smoothly. After re-plugging in vacuum line, check engine light didn't turn back on and hesitation continued. Im going to pull the EGR and clean. So process of elimination would tell me its the EGR ports if problem still persists. It could be assumed EGR has been cleaned but not EGR ports in intake manifold cleaned on an Accord with 250K miles. Thank you again for all the info. Will keep updated.
Hi, i appreciate your helpful videos on the P040x codes and I'm learning a lot! I have a question for you. I did the first EGR test by applying vacuum to the valve with the engine running on my Ford Windstar 1998. What I'm getting is the engine stumbling, but not shutting down. The system holds vacuum and I can hear the pindle move in the EGR, so I'm assuming the EGR is good. Does the engine stumbling indicate partially blocked passages, enough to set a P0401 code, or should I look elsewhere? Thanks!
Interesting series so far. However, you have only tested the EGR (exhaust gas recirculation) Valve and the EVR (exhaust vacuum regulator) solenoid. Are you going to test the DPFE (differential pressure feedback EGR system monitor) sensor in part 3? Finally, as has been pointed out by other comments, the purpose of the EGR system is to reduce oxides of nitrogen (NOx) by inserting exhaust gases (an inert gas) into the combustion chamber during cruise or moderate acceleration. This results in lowering overall combustion chamber temperatures which reduces NOx.
Correct on all counts. Being familiar with GM models, I am not familiar with DPFE which I associate with Ford models. Others pointed that out as well. I will need to do that for Part 3, Hopefully I can get a car with DPFE by then since I will need to learn about it myself too!
Schrodingers Box If, as I understood you narrative, this is a 2002 Ford Windstar, it has to have a DPFE sensor (i.e., unless this vehicle is no longer in your inventory).
johnwrench4speed Correct but I already did the work on it and returned to owner. I no longer have it. I totally whiffed on the DPFE. Dang. I will definitely try to make up for it next video.
you give good intel , i have 94 ford f150 it runs smooth at idle ,once you give it throttle it bogs out at high idle what is problem, cleaned all, change sensors around throttle body , EGR open and closes fine, watching your program maybe solenoid ?
Yes I really need to do a video on DPFE. it is a reference system used in a lot of Ford models to ensure the EGR is working but measuring a pressure difference before and after EGR when it’s open.
The voltage going to my 1990 f150 egr relay is only 5 volts. I'm getting a code 34 on my odb1. Checked the valve function, seems good. Helpful vid, but I'm not finished yet. Trying to figure out if I should have 12 volts going to the egr harness or if five is sufficient. Also if 5 isn't where to go next?
Schrodingers Box. Man you're good. That is exactly what I was doing. Not realizing the EVR selinoid was right under it. Found it when I was checking for a leak in the hose. I removed it, and put 12 volts from the battery, and didn't hear a click. Going to mess with it tomorrow more, but pretty sure this might be my issue. Thanks for replying.
Great video. So when I test the resistance on my Solenoid it's not like yours (doesn't remain constant). It jumps to 33 ohms or so but then drops down. Is that a sign of a bad coil/solenoid?
Hello thanks for the explanations. please you can help me i have a vw touran 1.9 tdi 105 hp diesel difficult to start after 20 minutes stops. just before stopping starts to vibrate. and the hose does not go out of vacuum. after diagnosis i found code p0234 what do you think cordially
Do you have any suggestions for finding some detailed descriptions of a specific EGR system for a car? I have an issue with a 95 Merc. Benz C280.. I think I've located the EGR valve, but there's also a "check valve" that looks very similar and I'm not sure where the solenoid is :/
+Yusuf Ibrahim Should be easy to find by following along on the video but really a service manual is your best bet. I often google diagrams with mixed results but especially on a Benz- you will surely want a service manual or get a ALLDATA DIY subscription just for your car only.
It could. I always start with the extreme basics on a "idle hunting issue"- start with IAC count responsiveness to variables on fuel trim and see if that's your issue before you do anything else.
truck didn't have no check engine light on ,truck runs fine on idle ,but when you pickup rpms to about 2500 engine wants to die out like no power ,when you release throttle it goes back to normal idle ,check all air hoses ok, replace all sensors on throttle body, removed egr to check ok , cleaned it nice it works can see and here valve open and close.,
I haven't read through all the commens, so possibly it is mentioned in there, but I am just curious is it safe to do isolated manual solenoid tests at 100% duty cycle? Many solenoids will burn out if 12V is applied and left on for a minute or two, but I don't know if this is also true for these type of solenoids? I just mention that in case someone believes its okay to leave it on for a long period, when that is maybe not true. One other point regarding testing a solenoid in isolation, many people believe that it doesn't matter which terminal has 12V applied to it. If the solenoid has a transient voltage suppresion diode built in, it is easily possibly to burn our the diode if tested with the supply attached to the wrong terminal. I have seen people on forums wonder why they are destroying there replacment solenoids during their testing phase, even before the solenoid gets fitted into the car. "Experts" informed them that the polarity is irrelevant for testing, but that is far from true.
are all egr valve resistor resistance all the same ? My 2002 civic Egr valve has no resistance on both side pin but between the middle pin and one side pin it measures 5K ohms. Does it mean that EGR valve is Faulty?
I see in your later video's, that you have in your possession, a Snap On OBD2 computer... How much did that set you back? I only ask because the Snap On Rep, who visits my workplace, went to charge me $4000 AUS dollars ( and that was on special haha ). It's the exact same model used in your later video's, too which I was coerced into to buying it, but hey, it would've been awesome to have one and I almost had it, but, my credit line didn't extend far enough...DAMM
I don’t own a snap on scanner. You must be referring to the scope which set me back $600 for a complete 2 channel kit with AMP and inductive and capacitive probe sets.
When I tested the egr valve with a vacuum pump, the car sounds like it wants to turn off but doesn't and the vacuum does hold from the vacuum pump. What it this telling me?
Sorry to annoy you with another question (Last one I swear), to which I'm sure you've already been asked (but I'm to lazy read through the mountains of comments through your other videos haha), where did you get your 12Volt probe? Was it online? Or was it at Your local auto-parts store?... I ask because no auto parts store within my country (Australia) seems to know what the hell I'm on about when I describe it. It gets really frustrating a lot of times.
HELP - I have a Mercedes Benz E220 CDI W210 with EGR problems BUT it does NOT HAVE an O2 sensor..! I checked the entire exhaust from the manifold to the tail pipe and zip. I checked on Autodata and Tolerance data providers and the schematic for the engine management system (Bosch EDC 15C0) shows all the usual sensors but no O2. I do not understand how the system works without the 02 sensor. I have good live data from the usual intake sensors but bad idle when hot (surges every few seconds) high CO emissions and seemingly random data from the EGR % data stream. Any Ideas please - how can the system work without exhaust sensor? In desperation I have to admit to replacing the EGR valve and it's solenoid but no change. I don't understand how the system works so its very hard to diagnose, any pointers gratefully received.
@@SchrodingersBox OK, Many thanks for your reply. I can't see how the system could work without one, but hey, guess Mercedes know something we don't...
I dont understand why you are measuring the resistance instead of the voltage to battery +. When you measure resistance the DVOM has to send voltage through the circuit that you are measuring. (Maybe bad for the divce/PCM that is in the circuit) If you measure voltage the worst thing that could happen would be a short to grund in the lead from your dvom to Bat+, it would only kill the lead. Since these leads are insulated that shouldnt happen.
But lets see it simple, as long as you dont put your leads in the ports for amp measurement (or on 2 port dvom's setting them on A) the voltagemeasurment is the savest. You a ECM when you shorten the wrong pins, regardless of resitance or voltage measurement (if the leads touch each other), but you can not destroy any ECM with a correct voltage measurement. In contrast it is possible the destroy an ECM with a correct resitance measurement. The best example are Hall-effect sensors, they nearly allways have an intigrated ECM and in every lesson, book and manual that i had it stated: "Do not do resistance measurement!" I never did cause if what i know... so i cannot say if this is over reaction, wanne test it? ^^
yea you are correct. That's why i did the resistance measurements with the component removed from the car. No chance of destroying PCM as you correctly pointed out because PCM is not involved in the method I showed with component off the car. In he case of what I did on the car wth resistance, I specifically said not to do those unless you know what you're doing. what I did was safe as acceptable though I agree voltage measurement would have been better anyway. I just wanted to show multiple methods and how they compare.
Need help understanding these codes don’t want to waste money on getting carbon cleaned and the problem turns out to be electrical can anyone help Can my codes on an Audi A5 2013 tdi still have codes of 1) EGR valve open circuit 2) Exhaust gas Recirculation Sensor A circuit/range performance 3) EGR valve open circuit If it was just totally blocked could I get these codes especially number 3
South Main Auto Repair Me too, just watched your vid before watching Matt's part 2. Slick move on your part ( Brake Torqueing ) in gear to activate the EGR system. But that was pretty slick on Matts part with the ohms test for the DIYer but I am a little leery as Steve Rob said, on the positive wire ( for that matter the negative side ( PCM ) ) should be load tested with a appropriate test light. The light will provide a load to determine if the wire can carry current, at the same time it will provide some resistance for protection of rampant current flow thru the PCM.
Thanks Billy R. That method I used does not always work. Some times the PCM needs speed sensor input to activate EGR. Depends on its testing strategy really. I agree about the use of an ohm meter to detect a ground switching signal from the PCM, probably not the best method to employ. I expressed my concern to Matt in another post but I don't think he saw it. My concern was is the fact it was not an auto ranging meter and it was set on 20k Ohms and it only dropped to 5.xx during the test, I might have missed something though. Any how we will see what part III brings
Looking forward to checking out some of your other vids! By the way you wouldn't be located in CT, because I think we have a garage around here named South Main Street Garage
That may be right if it has a vent depending on the design. Also if it is a solenoid that is always stuck open when it shouldn't be- try testing with just the key ON.
My is operated by vaccum and i figured once it was running some check valve in the unit must be opening preventing me from putting vaccum on it... It is a 95 Cavalier so of course nothing reads it as in a scan tool... It has both OBD1 and 2 in the computer ... so I literally have to test everything oldschool...
+Schrodingers Box , First let me say I an trying to not be a parts changer, and thank you for the help. you were saying that it would not be easy to drive your car down the road while doing one of the tests that you were performing on the EGR. But you could jack up the drive wheels onthe vehicle and watch the results from the side of the car
+Randy Ingrao Ah I gotchya- forgot what this video is about. Yes I mention in the video that jacking the car up is an option to simulate the driving conditions that would activate the EGR
I don't think I have ever come across a more concise, succinct and clear set of teaching videos. A week ago I knew next to nothing about cars and I have been watching youtube videos non-stop for a week. Your videos are the only ones I've come across that a) take this logical, diagnostic approach to fixing cars and b) recognise that the ECU is central to how cars now work and it therefore needs to be at the centre of any auto mechanic's thought process. Thanks for putting in the time.
Thanks man! Glad you found the channel. also check my website at www.schrodingersboxqm.com
My volvo 940 has egr, pulse air, & pcv systems ..
My mechanic who has managed my car for 6 yrs has caused so many problems .. after much frustration with high idle, water pump they put in that leaked ever since they put it in, radiator replacement, misdiagnosis, they don't dx anything, I learned every thing about my car, and I have it running well, found both pulse air valves dried with carbon replaced them, cleaned all connection with elect contact, fixed throttle position sensor as they must have messed with the screw adjustment so no click, cleaned throttle body all small holes as well, cleaned the egr metal pipe intake like u said it was clogged, the air box thermostat was stuck in hot position only, replaced thermostat that was stuck, pcv system was disconnected and the plastic filter clogged and hard, replaced that, replaced relays, applied new heat sink to the ignition module as it needed it, replaced fuses, water pump,
timing belt seals, spark plugs, cleaned injectors and replaced the microfilters inside that were crumbled into pieces, it sounds good now, idle seems perfect, I have to adust the kickdown cable little more, they had put a loose air filter in my car that didn't fit my air box a lot of dirt getting in, cleaned my MAF sensor, and getting ready to remove the egr to clean the openings,but since the intake egr pipe was clogged like u said what caused all these issues,was it the pcv .. why is their 3 system like this to manage. I'm a 66 yr old woman who up until this year only went to mechanics, and relied on them to know what they were doing but they seem to have no clue about lean or rich codes, didnt know how to do my codes.. now I'm having to replace the power steering line they put in
So I paid them so much money over he years . Seems like they would have done the fuel filter, put the right air filter in or made some effort to check the pcv etc..
Man you are good. Thanks for explaining all of this with great logic. I haven't seen one other video that takes the time that you do to make sure everything is understood so well. Great job teaching. All ford 150 owners from 97-02 should watch this video series.
Thanks for appreciating it! Most people don't. They say :Hey you never do anything to fix the car- this is stupid" lol
This is great but I must be doing something wrong. I tested everything (I think). I have replaced the EGR, vacuum solenoid (aftermarket), DPFE sensor (OEM), checked the electrical output, cleaned the throttle body, intake, EGR tube etc. The car is running very smooth but I keep throwing a p0401 code. This is a 1997 ford f150 w/4.6 liter 4x4. Any further recommendations would be greatly appreciated. My fuel trims look fine as well.
@@TimFleisher Well I would need to see the EGR data that indicated it was fauilty. What was the test that vacuum solenoid was faulty?
@@SchrodingersBox well im an idiot. i had the DPFE hoses switched...I checked it like three times but was only looking at hose length rather than the size of the connection on the DPFE and the EGR tube. So dumb...alas that was my problem. thanks for the videos. i learned a lot that i will probably use later. If you ever do things specializings in subaru wrx's (2003 :-)) that would be great.
You are correct, anytime I have asked others about egr operation, I just get a bunch of ways to remove it or bypass it
when you say your a scientist, does mean your a high grade science teacher?? its just you have a natural ability for teaching a novice overall demographic about engine components is all... you really are a great teacher, THE BEST on YOUTUTBE!!!
Thanks man- no I am an actual, like, scientist... DNA, Proteins, genetics...
Appreciate your time giving us a better understanding.....
Great video series. I repair used cars, boss told me car had some kind of code for exhaust flow and to check exhaust for leaks and weld it if need be. Code was p0401.... fun times, still haven't been given chance to diagnose it further after telling him it has nothing to do with exhaust leaks.
Great 👍 Info.. Good Detail never took the time to really understand the EGR system thanks for the help
You're welcome!
It's funny you should say something about hooking up a system to test while driving because the other day our computer crashed and I actually had to rig a way to test control and activation of the solenoid. We made a plug to plug into the connector and ran a wire into the car that we could hook the meter to. Man it looked funny and we had a code or 2 pop up as a result but it worked beautifully. That's that diagnostic mindset of making sure to test every component thoroughly lol. Great vid Matt.
This made me remember the different colored Ford EGR vacuum delay valves. Bunches of fun. Ancient history now.
Hahahah That was before I got into this but I know what you are talking about!!
Clear step by step video with a good basic theory foundation.Looking forward to the next episode of "mission impossible"
Tom OConnor Thanks man, I'm starting to get a system down now for this style of presentation I think!
I have a 1999 Ford F-150 XLT, 5.4 Liter, Sport 4x4. I must say I am wheelchair bound, partial paraplegic, and for the most part and trying to work on my truck is difficult at best. It started showing a PO401 error code not long back. Well the first thing checked was of course the EGR valve and trying a vacuum test, etc. it was bad. I even tried to clean it out but to no avail. Well after replacing the EGR valve about three weeks went by and that code popped back up. So with help from a friend we checked the vacuum lines and replaced all of the bad rubber vacuum lines which could be found no matter where they were located. Again, that cured the problem for another month. The code pops back up. Well with help he just happened to stumble on a broken green vacuum line which runs from the electronic volume vacuum flow solenoid to the top of the EGR valve as you showed it on your video above with it sitting on the cowl panel. So we replaced that line and I instructed him on how to do a simple vacuum test from the electronic volume vacuum flow solenoid to the EGR valve to see if the engine would stall out while running. Nope, nothing happened. It ran pretty and smooth at 650 to 700 rpms. Now back in the autumn the intake manifold was somewhat cleaned but from looking dead on inside but it didn't really need to be cleaned nor was it removed from the manifold so I have no idea if the two small EGR tunnels are plugged up or even just partly plugged up. Based upon how clean the other tunnel seemed to be right there at the EGR valve seemed to be when the factory EGR valve was removed, it was cleaned out as best as possible in loving care with little to show for the effort. The factory EGR valve was cleaned as well with hopes I can continue to use it with little to show for the effort but still even that did not save the day. Another friend hooked up his professional code checker and the entire engine checked out perfect between long extended times when the PO401 error code popped up so that just adds to the confusion. Just yesterday coming home from the hospital I noticed the check engine light came back on and guess what the code was? So I started making calls to almost every local mechanic and every one of them agreed, in these words, that there is a 95% chance it is the original factory metallic DPFE back flow solenoid. Now, granted I have no way to check that electronic volume vacuum flow solenoid and I also have no way of checking out the DPFE back flow solenoid, nor do I have any way to check the remaining rigid plastic green, red, and yellow vacuum lines to see if they are leaking. I must also admit that very recently I had to get the exhaust manifold leak repaired at quite some cost to me but I give many thanks to God that each broken exhaust manifold bolt, all three of them, were broken on top of the exhaust manifold. I am running out of ideas and to be honest I have not ever had this much of an issue with a EGR error code before on any vehicle I had owned up until now. Can you please provide me with any possible hints on something which I may be able to try? From what I am now hearing from so many professional mechanics now that I have asked in the surrounding local area, it may actually come down to biting the bullet and actually changing out that factory metallic DPFE back flow solenoid which everyone is saying has given so much of an issue in the past and was why Ford went to the plastic DPFE back flow solenoid.
What happens at idle when egr valve is activated?
You guys in the States get the best wiring diagrams in the world! You don't know how luck you are! Over here in the UK you get black lines going to black outlined boxes lol.
If we're lucky we'll get told what colour the wires are! :-) Where do you guys get wiring diagrams with '5v ref', 'control wire' etc, you are so lucky!
I search mine from Google. Pretty sure you have access to that wherever you are lol so you are lucky too!
@@SchrodingersBox I thought maybe you subscribed to a vehicle data site, ondemand5, Mitchells etc.
In the Uk biggest ones are Aldata, Autodata, Haynes pro and none of them mention the 5v reference circuit, control wires etc.Especially within a pcm or something similar.
I do know how to figure out these things for myself as i'm on a vehicle tech course, but for quickness it's really handy to have everything on a good data subscription site, rather than ploughing the vast void that is Google.
No- being a Do It Yourselfer I can't really justify a subscription to a service. If I did, I'd use Mitchell- I like their diagrams better than Alldata.
Excellent video. I really look forward to this style where you explain the concept and then show how it works on an actual car or track down a fault. I was curious about how you did the testing on the signal integrity to the vacuum solenoid. Why not leave the solenoid hooked up and backprobe on the ground side measuring the voltage. That way the computer sees the load it is expecting and you get a functional test of how well the computer can pull the line low with the load in place.
Keep up the good work and can't wait for part 3.
Steve U That would have been a better way to do the testing and in fact was my first preference, however the problem was I just didn't have enough clearance when the valve was connected to ensure the backprobes didn't touch themselves or more likely, a ground. There was just way too much concern of shorting the power to ground because of the design of this vehicle and it would almost guaranteed fry the EGR driver in the PCM.
The vehicle I will use for Part 3 with the electronic EGR is much friendlier location and I will be able to do the testing the way you describe.
Excellent Matt well instructed. The egr harness signal interigity test , while testing on ohms , interesting. As for the pos. side of the circuit tested unloaded can be misleading if you suspect an input to the egr fault. My RUclips drivability instructor has proven the value in the loaded test for voltage whenever possible to detect an inability to carry currant . I only do loaded voltage test. Fantastic Matt look forward to part trois
Steve Rob Thanks man, you're always there to support the channel bro!
Yes, I haven't seen the resistance version of testing this anywhere else. Much safer.
STEVE ROB REVIEWS t
I'm behind in checking your videos... when you checked the solenoid with a vacuum pump, vacuum would have held if you had attached the pump to the "manifold vacuum side" of the solenoid. The EGR side "drops" vacuum because of the "air bleed" (part of the solenoid) that allows the component (EGR, diverter valve etc) to close when the solenoid is not energized. Disconnecting the solenoid to "test" the ground can / will set a fault code, since the PCM no longer "sees" the voltage going through the coil / solenoid. On VW's it'll set "open or short to ground codes " (for whatever the solenoid controls). As always, lots of good info and the comments below the video also provide good reading!
***** Thanks man, and love your channel as well. Fascinating to see how the pro's zip through things far more efficiently than I do lol!
Schrodingers Box I'm far from being a pro... that's why I watch youtube and subscribe to channels where I can learn a thing or two! :)
If I am understanding this ........If I had a p0401 (insufficient flow) along with p0171 and p0174 (bank 1 and 2 lean) I would want to inspect for a vacuum leak that is causing weak vacuum in the EGR. If I was stuck open it would possibly cause lean codes but the insufficient flow would not be an issue if I am following you correctly. Would a vacuum leak large enough to cause a lean code hinder the vacuum strength in the EGR? Haven't had a chance to dig in yet, I'm just trying to put my thoughts in the right direction.Thanks for the lesson!
I suppose its possible. If I had both codes, I would start with P0401 first by checking the EGR if it is stuck open or not. If it is, that is likely the source of both codes. If however the EGR is closed at idle, I would start with a fuel trim analysis first to determine cause of lean condition first.
@@SchrodingersBox Thanks for the reply. My first stop will be to see if I can manually manipulate the EGR with my hand held vacuum pump. If I can I will work backwards from there to the vacuum solenoid. If I can't I will pull the valve and check for carbon build up. Again, thanks for the great explanation!
Yes the egr intake pipe was clogged at the top like u said but I can't get the egr off to clean it, I sprayed MAF sensor cleaner inside the valve, and cleaned the electrical connections but Im now worried that I could have damaged the diaphragm with cleaner and cannot get egr off
thanks for the tips on egr valve
I know with GM OBD1 you can get the car into diagnostic mode by shorting pins on the ALDL which does exactly what you had there with the air pump coming on etc with key on engine off. It's a little easier to troubleshoot since that mode basically commands "on" components that would normally be inaccessible without a scan tool and you can leave parts in place. Most OBD1 and OBD2 cars have a "Field Service Enable" pin that can make the magic happen but you have to know how to get the car into that mode without a scan tool. Not impossible but a little tougher.
I’m sure you’ve figured this out by now, but, had you’d put a T pin on the secondary “power” wire with the plug plugged in, you could use a test light to use as a ground side switch. Basically, hook the yes light on the T pin and then touch the T pin with the test light thus grounding the power feed.
Hello Matt, my name is Peter, I have 2006 Suzuki Grand Vitara 2.7. I've had rough idling and hard engine start especially when the car is already warm, basically I have to crank it a lot to get it going when the problem is present. I get the P0401 code for insufficient exhaust gas flow. So with a mechanic we took apart everything on top of the engine and cleaned the EGR passage and the pipe that goes to the exhaust manifold, cleaned throttle body and so on... I am thinking now if we might have missed something when we were doing the job. I can't remember if we cleaned the lower and upper joints of the pipe that gets the exhaust gas to the EGR,(we did clean the pipe itself, not sure if we cleaned the continuation of that pipe where it connects on the upper and lower side) also where ever the EGR itself gets connected to, I am not sure we looked and cleaned that too ( we just cleaned the two EGR holes where the valve is) Just thinking of what we might have missed because now, 300 miles later after the cleaning, I got that rough idling again with the exact same code and symptoms, so I am wondering if we might have missed on a dirty clogged part on the system or there might be something else. What would you suggest me to do and check for based on the symptoms I am getting and also having in mind that it happens, then is stops in few days and then comes back like 500 miles later, been like that for the last 8k miles... The mechanic doesn't have the sucking tool, but we don't think the EGR valve is faulty because most of the times I don't have the issue, I just think that we missed to clean a spot where there is a carbon build up, what do you think ?
What data do you have?
@@SchrodingersBox I don't understand the question
What is your eve commanded position? what is the fuel trim adjustment with manual EGR operation? What is the duty cycle? There is no information that can be used to make a diagnosis.
Unfortunately I don't know or understand any of those questions, nor I know where to find them, I uploaded the full service manual of my car here, upstore.net/DdL3sgL would that give you the answers needed ?
Well I learned an expensive lesson today, Do not try to take your EGR tube off down at the exhaust manifold just to check if it is blocked. The thread got all messed up while I was undoing it on both the flange nut and the adaptor going into the manifold, then I could not get into it to undo the adaptor so I had to pull the whole exhaust manifold off and then while I was trying to undo it the the whole thing snapped off. So now I have to buy a complete new manifold with the EGR pipe and I can only get one from the US and I live in the Philippines now from Australia so all up it cost me $280 US and my car will be off the road for 2 weeks or more waiting for the parts to arrive. And the worst part is that the pipes where all nice and clean. I then carried on with my testing and found the problem was the EGR solenoid that was not working so it was a pity I did not test that first before I tested the EGR valve vacuum can and then decided to take the pipe off to check it was not blocked at the manifold while I already had the EGR off. I should have just blown compressed air down there first to check if it was clear or even used a piece of wire down the tube.
Ugh sorry to hear that!!
Yeah it won’t be blocked at the exhaust manifold anyway. It will always only ever be blocked at the intake side.
@@SchrodingersBox Another RUclipsr suggests checking the manifold end of the tube for blockages so I thought I would just check it while I had the chance. I can't run it now until I get all my parts but I hope the new solenoid fix's my P401 code and check engine light I keep getting .
Matt, what I did not understand is that when you were testing the power and ground wire, you had constant power there, you said it was ground side switched, but you measured ground continuity. If the ground circuit from PCM is open, how would you get continuity and resistance. Would appreciate if you explain this tiny detail.
Thanks Matt for your videos!
This is explained in detail in my basic electrical series but there actually isn’t constant power because the pulsewidth modulation is too fast to see the ground side control.
There is a thing I can't figure out.
How do you measure resistance on the solenoid when you have current on it. That should wreck your DVOM, right?
Ohm's Law.. You get a current reading and divide into voltage reading.. This is just my guess however...
"ground side switched" ...sounds like a good video to me!
Haha like an X-rated one maybe
Hello, I have a 2018 impreza . Standard boxer engine 2.0. My car has direct inject. I am very concerned about carbon build up due to this fact. I have already installed a catch can on the p c v . I have concerns about the e g r sending gasses into my intake . I don’t have any fresh fuel continuity cleaning the back of my valves . Please share any thoughts on how to combat this issue. I am considering the ole e g r delete not for racing but to stop recirculating crap into my intake . Any suggestions or knowledge you can share is greatly appreciated . On another note you are playing on your own field. Definitely received training above and beyond most I see .. 👍
Most informative. Thank youI have a question about the throttle position sensor and the EGR valve.Can the TPS effect the EGR valve operation. Thanks
Well- in a way... when throttle is open it may command EGR open depending on conditions but there isn't a direct link between EGR and TPS- it's more of an indirect effect.
You know Matt I was thinking. When we open valves at idle to see if the car "dies", does it die from and extreme lean condition or do you think it dies because we introduce a large amount of inert gas that it can't combust? I was eating my dinner and just thinking of that actually.. I don't ever recall looking at STFT while opening the valve and having the engine running rough to see what it does... hmmmm. Sounds like time for an experiment!
Also just a thought on the meter and the test. I guess I have never tested for computer control using an Ohm meter, any how not to be Debbie downer but the meter was set on the 20k setting so when it dropped to 5.xx ohms that actually wasn't ground was it? Any how just a thought, next time when you are checking to see what side of the solenoid is power load it a little (ie. test light) other wise both sides will show 12v + using a high impedance dvom. Just a couple thoughts. I'd love to discuss this a little further if you like. PM me if you want to chat a bit. Got a million things on my mind all the time haha. See u in part III!
Yeah I will cover in Part 3 but trustme, even just a little EGR and the O2's voltage tanks and STFT adjusts lean. You would expect rich response but it is indeed very lean. I am not sure the reason yet- I agree, inert product should lean the sensor. It could also be a MAP thing but even so, the MAP would add fuel and O2’s should show rich then. Still working on that one lol.
Actually correction, Inert gas should induce rich because it dilutes the O2, less O2 to be sensed. Definite experiment in the making here!
BINGO... my thoughts exactly...
South Main Auto Repair
You two got me really thinking with this set of comments. That's my favorite reason to be here!
DE Nichols
These experiments could end up in the Cern particle accelerator at the sub atomic level. Where did I leave my final year chemistry manual ? Have they scrapped the periodic table yet?
on my 95 lexus sc400 v8 the engine has a rough idle and sputters. i have a check engine light on. when i press the gas the rpms on the tach go in the wrong direction. they go down instead of up like a vacuum leak or something. so far i put fresh gas and cleaned the throttle body out which was very dirty with carbon build up. that cleared the check engine light however after 30 minutes it came back. when i smoke tested the engine i did have small leak from what appears to be the gasket of the egr valve. can the egr valve and gasket this be causing my issue?
Could be. What data do you have?
Hmm... It may also be the case that the PCM won't activate EGR controls until it's in closed loop. If you think about it, the primary concern of the PCM is to get the engine into closed loop as quickly as possible. Enabling the EGR system lowers combustion temperatures, and in theory, would delay the engine warming up. Just a thought, though; not sure if it's accurate.
Man, I do believe I failed to mention that in the video. You are correct, EGR is in closed loop, it is one of the times EGR is bypassed and I failed to mention it. Nice catch!
Schrodingers Box
No worries man. There's lots of great information here; I can't fault you for that. :-)
I performed the vacuum test on the EGR valve. When I initially tried it, I would get to about 20lbs and the engine would nearly die but stay running, hardly. The second time I vacuum tested (with car still running from previous test, and releasing vacuum to return to normal idle), I did get the car to die with a few hard pumps (of the hand operated vacuum pump like the one you used) to roughly 15lbs.
My questions being..
Is more than 20lbs of vacuum required to kill the engine, i saw you used about 10lbs and the engine dies on your end.
Would this be a clogged EGR Valve, or clogged EGR ports. Also if I find the EGR valve is clogged is it a good indication that the ports leading into the manifold are clogged as well and should be cleaned for good measure, is there a test?
Refering to a 92 Accord 2.2 having 4 EGR ports on the intake manifold.
Thank you for the videos you have posted thus far, exactly what I was looking for rather than getting balls deep into parts swapping.
Cheers,
Chuck
Update:
Last night while my vehicle was sputtering after being warm, I pulled over and I unplugged the vacuum line to the EGR (in attempts to narrow down the cause of the hesitation. I was greeted with a check engine light as expected and the vehicle wasn't engaging EGR so it was running smoothly. After re-plugging in vacuum line, check engine light didn't turn back on and hesitation continued.
Im going to pull the EGR and clean. So process of elimination would tell me its the EGR ports if problem still persists. It could be assumed EGR has been cleaned but not EGR ports in intake manifold cleaned on an Accord with 250K miles.
Thank you again for all the info. Will keep updated.
Yet another great video. Cheers my friend.
Since you forgot to include the DPFE valve.If there is vacuum at the green vacuum hose,could it be a faulty DPFE valve?
Hi, i appreciate your helpful videos on the P040x codes and I'm learning a lot!
I have a question for you. I did the first EGR test by applying vacuum to the valve with the engine running on my Ford Windstar 1998. What I'm getting is the engine stumbling, but not shutting down. The system holds vacuum and I can hear the pindle move in the EGR, so I'm assuming the EGR is good. Does the engine stumbling indicate partially blocked passages, enough to set a P0401 code, or should I look elsewhere? Thanks!
At full open, the engine should die for sure. I would suspect partial blockage but I usually validate through fuel trim adjustment during the test
Interesting series so far. However, you have only tested the EGR (exhaust gas recirculation) Valve and the EVR (exhaust vacuum regulator) solenoid. Are you going to test the DPFE (differential pressure feedback EGR system monitor) sensor in part 3?
Finally, as has been pointed out by other comments, the purpose of the EGR system is to reduce oxides of nitrogen (NOx) by inserting exhaust gases (an inert gas) into the combustion chamber during cruise or moderate acceleration. This results in lowering overall combustion chamber temperatures which reduces NOx.
Correct on all counts. Being familiar with GM models, I am not familiar with DPFE which I associate with Ford models. Others pointed that out as well. I will need to do that for Part 3, Hopefully I can get a car with DPFE by then since I will need to learn about it myself too!
Schrodingers Box
If, as I understood you narrative, this is a 2002 Ford Windstar, it has to have a DPFE sensor (i.e., unless this vehicle is no longer in your inventory).
johnwrench4speed Correct but I already did the work on it and returned to owner. I no longer have it. I totally whiffed on the DPFE. Dang. I will definitely try to make up for it next video.
you give good intel , i have 94 ford f150 it runs smooth at idle ,once you give it throttle it bogs out at high idle what is problem, cleaned all, change sensors around throttle body , EGR open and closes fine, watching your program maybe solenoid
?
Can't tell unless you provide me some basic data bro!
Whats the brand and model of the vacuum tool you are using to diagnose EGR valve and solenoid?
It’s an old mity-vac
DPFEor PFE does it not play part in “signal “ or “vaccum “ for EGR VALVE
Yes I really need to do a video on DPFE. it is a reference system used in a lot of Ford models to ensure the EGR is working but measuring a pressure difference before and after EGR when it’s open.
The voltage going to my 1990 f150 egr relay is only 5 volts. I'm getting a code 34 on my odb1. Checked the valve function, seems good. Helpful vid, but I'm not finished yet. Trying to figure out if I should have 12 volts going to the egr harness or if five is sufficient. Also if 5 isn't where to go next?
Sounds to me like you are looking at reference. Are you sure you aren't measuring the potentiometer?
Schrodingers Box. Man you're good. That is exactly what I was doing. Not realizing the EVR selinoid was right under it. Found it when I was checking for a leak in the hose. I removed it, and put 12 volts from the battery, and didn't hear a click. Going to mess with it tomorrow more, but pretty sure this might be my issue. Thanks for replying.
Question...The EVR switch...Does that activate under pressure or vacuum to send the 12 volts to the return?
around 12:20 why is there resistance at the ground side switch and why does it drop when u do the koeo non-running test?
Great video. So when I test the resistance on my Solenoid it's not like yours (doesn't remain constant). It jumps to 33 ohms or so but then drops down. Is that a sign of a bad coil/solenoid?
Just put current through the control side and measure continuity at the load. There should be no resistance whatsoever on the load side.
I look forward to part 3 =)
Fuckin awesome. Gotdamn I really didn't wanna know all this shit... but I sure am grateful to ya my man.
Priceless
Hello thanks for the explanations. please you can help me i have a vw touran 1.9 tdi 105 hp diesel difficult to start after 20 minutes stops. just before stopping starts to vibrate. and the hose does not go out of vacuum. after diagnosis i found code p0234 what do you think cordially
Do you have any suggestions for finding some detailed descriptions of a specific EGR system for a car? I have an issue with a 95 Merc. Benz C280.. I think I've located the EGR valve, but there's also a "check valve" that looks very similar and I'm not sure where the solenoid is :/
+Yusuf Ibrahim Should be easy to find by following along on the video but really a service manual is your best bet. I often google diagrams with mixed results but especially on a Benz- you will surely want a service manual or get a ALLDATA DIY subscription just for your car only.
+Yusuf Ibrahim nevermind I think the check valve is the solenoid! many thanks for the videos btw
Monitoring ur egr solenoid voltage,with ur scan tool, as u drive might show control
yes sometimes you have to do that if you do not have bidirectionality and the EGR is pulsewidth modulated.
Thank You... for lesson...very helpful
Can't we just supply 12v to the egr valve while car is running to manually turn it off/on that could tell us if the problem is in power supply?
what if it is pulsewidth modulated though?
Would this have anything to do with idle raising and lowering sporadically? All I get is an O2 code.....
It could. I always start with the extreme basics on a "idle hunting issue"- start with IAC count responsiveness to variables on fuel trim and see if that's your issue before you do anything else.
truck didn't have no check engine light on ,truck runs fine on idle ,but when you pickup rpms to about 2500 engine wants to die out like no power ,when you release throttle it goes back to normal idle ,check all air hoses ok, replace all sensors on throttle body, removed egr to check ok , cleaned it nice it works can see and here valve open and close.,
Could be anything -What data do you have? Especially why change the sensors on TB- what data did you have indicating this was potentially the issue?
I haven't read through all the commens, so possibly it is mentioned in there, but I am just curious is it safe to do isolated manual solenoid tests at 100% duty cycle? Many solenoids will burn out if 12V is applied and left on for a minute or two, but I don't know if this is also true for these type of solenoids? I just mention that in case someone believes its okay to leave it on for a long period, when that is maybe not true. One other point regarding testing a solenoid in isolation, many people believe that it doesn't matter which terminal has 12V applied to it. If the solenoid has a transient voltage suppresion diode built in, it is easily possibly to burn our the diode if tested with the supply attached to the wrong terminal. I have seen people on forums wonder why they are destroying there replacment solenoids during their testing phase, even before the solenoid gets fitted into the car. "Experts" informed them that the polarity is irrelevant for testing, but that is far from true.
Yes it is
I think your videos are excellent by the way. Thanks for taking the time and making the effort to create them.
I have water in my secondary air pump of my passat 1.8t passat. With bank 1 lean code and air flow code. Do you think EGR is stuck half open?
No idea. what data do you have?
@@SchrodingersBox i don't know what you mean by "data" I ran codes and the codes told me and I see very bad smelling water in 2ndary air pump.
What is best way to locate pcv valve on 08 ford F-150 4.2 L? I can't seem to find it.
I always start by looking at thge intake for it
what if we lift the car's driving side on a lift and actually run it on drive (i've seen a guy once doing this trick, with mechanical gear though
)
You can certainly do that, but it’s so much easier to activate it manually and validate operation through PCM response
are all egr valve resistor resistance all the same ? My 2002 civic Egr valve has no resistance on both side pin but between the middle pin and one side pin it measures 5K ohms. Does it mean that EGR valve is Faulty?
+HHOhybridBuilder Which terminals are you measuring? Signal, reference or ground?
I was measuring all. Can't get a resistance reading from reference to ground, sometimes it measures 19 k ohms, aren't those suppose to be 5KOHMS?
HHOhybridBuilder No I mean specifically- what were the measurements between the feed at signal and the signal and ground respectively?
could the steel tube that runs from the engine exst. manifold to the EGR valve cause theP0401 code also ?
+Robert Woolridgeyes indeed.
I see in your later video's, that you have in your possession, a Snap On OBD2 computer... How much did that set you back? I only ask because the Snap On Rep, who visits my workplace, went to charge me $4000 AUS dollars ( and that was on special haha ). It's the exact same model used in your later video's, too which I was coerced into to buying it, but hey, it would've been awesome to have one and I almost had it, but, my credit line didn't extend far enough...DAMM
I don’t own a snap on scanner. You must be referring to the scope which set me back $600 for a complete 2 channel kit with AMP and inductive and capacitive probe sets.
When I tested the egr valve with a vacuum pump, the car sounds like it wants to turn off but doesn't and the vacuum does hold from the vacuum pump. What it this telling me?
You need to consider other factors like the MAP, IAC position and fuel trim response to have more data to interpret that response.
Thanks, I noticed you have a video on fuel trim. I will take a look at that to see. Appreciate it.
Sorry to annoy you with another question (Last one I swear), to which I'm sure you've already been asked (but I'm to lazy read through the mountains of comments through your other videos haha), where did you get your 12Volt probe? Was it online? Or was it at Your local auto-parts store?... I ask because no auto parts store within my country (Australia) seems to know what the hell I'm on about when I describe it. It gets really frustrating a lot of times.
I believe I got it from Amazon if i remember correctly.
Thanks
Hi, we could use min max function wich some multimeters has
Good video
What's a Schrödinger? 🙋😀is it a thingamagig that connects to a cunatur valve or something? I like the video btw
+john argue Lol- Schrodinger's Box (or cat) is a thought experiment on quantum mechanical superposition. Hopefully that clarifies it ;-)
+Schrodingers Box cool 😺
HELP - I have a Mercedes Benz E220 CDI W210 with EGR problems BUT it does NOT HAVE an O2 sensor..! I checked the entire exhaust from the manifold to the tail pipe and zip. I checked on Autodata and Tolerance data providers and the schematic for the engine management system (Bosch EDC 15C0) shows all the usual sensors but no O2. I do not understand how the system works without the 02 sensor. I have good live data from the usual intake sensors but bad idle when hot (surges every few seconds) high CO emissions and seemingly random data from the EGR % data stream. Any Ideas please - how can the system work without exhaust sensor? In desperation I have to admit to replacing the EGR valve and it's solenoid but no change. I don't understand how the system works so its very hard to diagnose, any pointers gratefully received.
never heard of that. I have always ever seen an O2 or and A/F sensor on every car ever.
@@SchrodingersBox OK, Many thanks for your reply. I can't see how the system could work without one, but hey, guess Mercedes know something we don't...
After watching scannerdanner I can see several things he is unaware of that a Verus scanner would tell you.
I don't own a verus scanner so I have to do some of the testing manually. I wish I had a verus!
Could you not put her on jacks, then run her up to 2500 in drive?
Yes you can and in fact it's a legitmate way to do it.
Try testing valve in neutral?
thanks!!
Me i put a piece of paper in the hose to see if it will suck the piece of paper to check if the solenoid is working
Correction : egr signal return and feed integrity test. Wow I could have got a detention for a slip up like that. LOL
I was going to mention it but I figured that's what you meant lol
Your getting to technical on me Steve! LOL!
Hi.. How can i get Auto Enginuity???
Autoenginuity.com. or call them and ask for my friend Bill.
I dont understand why you are measuring the resistance instead of the voltage to battery +. When you measure resistance the DVOM has to send voltage through the circuit that you are measuring. (Maybe bad for the divce/PCM that is in the circuit)
If you measure voltage the worst thing that could happen would be a short to grund in the lead from your dvom to Bat+, it would only kill the lead. Since these leads are insulated that shouldnt happen.
In Part 3 I do measure voltage. I show the resistance measurement because it's safer for people who aren't too familiar with electrical testing.
But lets see it simple, as long as you dont put your leads in the ports for amp measurement (or on 2 port dvom's setting them on A) the voltagemeasurment is the savest. You a ECM when you shorten the wrong pins, regardless of resitance or voltage measurement (if the leads touch each other), but you can not destroy any ECM with a correct voltage measurement. In contrast it is possible the destroy an ECM with a correct resitance measurement. The best example are Hall-effect sensors, they nearly allways have an intigrated ECM and in every lesson, book and manual that i had it stated: "Do not do resistance measurement!"
I never did cause if what i know... so i cannot say if this is over reaction, wanne test it? ^^
yea you are correct. That's why i did the resistance measurements with the component removed from the car. No chance of destroying PCM as you correctly pointed out because PCM is not involved in the method I showed with component off the car.
In he case of what I did on the car wth resistance, I specifically said not to do those unless you know what you're doing. what I did was safe as acceptable though I agree voltage measurement would have been better anyway. I just wanted to show multiple methods and how they compare.
02 Windstar,, WAHOOOO! My daughter has an insufficient flow DTC on her 02 Taurus w/ 3.0 DOHC
ahhh the green vacuum connction....
Run a vacuum line into the cab with a vacuum gauge attached. ???
+Ed Waggoner Sr. (Papatch) You can definitely do that.
Need help understanding these codes don’t want to waste money on getting carbon cleaned and the problem turns out to be electrical can anyone help Can my codes on an Audi A5 2013 tdi still have codes of
1) EGR valve open circuit
2) Exhaust gas Recirculation Sensor A circuit/range performance
3) EGR valve open circuit
If it was just totally blocked could I get these codes especially number 3
So what was wrong with the car?
Loose nut behind the steering wheel
@@SchrodingersBox Lmao
Watching
Ford mondeo 2001 2.0 felercod P0409?
Arif Aliji a p0409 means you have contracted AIDS
check out south main auto he just did a case study on a egr system on a honda he got it to turn on by brake torquing the engine.
Ha, I missed that lol- haven't had time to check out more of his vids.
Hey thanks for the prop phil holbrook I just left Matt the link in his first vid. First thing I thought of.
South Main Auto Repair Me too, just watched your vid before watching Matt's part 2. Slick move on your part ( Brake Torqueing ) in gear to activate the EGR system. But that was pretty slick on Matts part with the ohms test for the DIYer but I am a little leery as Steve Rob said, on the positive wire ( for that matter the negative side ( PCM ) ) should be load tested with a appropriate test light. The light will provide a load to determine if the wire can carry current, at the same time it will provide some resistance for protection of rampant current flow thru the PCM.
Thanks Billy R. That method I used does not always work. Some times the PCM needs speed sensor input to activate EGR. Depends on its testing strategy really. I agree about the use of an ohm meter to detect a ground switching signal from the PCM, probably not the best method to employ. I expressed my concern to Matt in another post but I don't think he saw it. My concern was is the fact it was not an auto ranging meter and it was set on 20k Ohms and it only dropped to 5.xx during the test, I might have missed something though. Any how we will see what part III brings
Looking forward to checking out some of your other vids! By the way you wouldn't be located in CT, because I think we have a garage around here named South Main Street Garage
CAN NOT BLAME HENNERY!
I have an EGR that holds vaccum when the car is not running but it will not hold a vaccum if it is running , go figure
That may be right if it has a vent depending on the design. Also if it is a solenoid that is always stuck open when it shouldn't be- try testing with just the key ON.
My is operated by vaccum and i figured once it was running some check valve in the unit must be opening preventing me from putting vaccum on it... It is a 95 Cavalier so of course nothing reads it as in a scan tool... It has both OBD1 and 2 in the computer ... so I literally have to test everything oldschool...
P0401 ?
Chingon sr 2%
17:28
Lift the rear reals and put her in gear to test..lol.
jack up your drive wheels
+Randy Ingrao Say what???
+Schrodingers Box , First let me say I an trying to not be a parts changer, and thank you for the help. you were saying that it would not be easy to drive your car down the road while doing one of the tests that you were performing on the EGR. But you could jack up the drive wheels onthe vehicle and watch the results from the side of the car
+Randy Ingrao Ah I gotchya- forgot what this video is about. Yes I mention in the video that jacking the car up is an option to simulate the driving conditions that would activate the EGR
FORD REQ CHANGE YOUR DIFFY FLUID EVERY 30,OOO WTF! WHO DOES THAT!
vss sensore f spell check we are talk'n pay check high mile ford 75 -140 syinpothetick in your pumpkinn head and a magnetic sensore check mate!
2004 chy egr prblems
Prvoo احسنت
ScannerDanner is cringing.
because of what?
THEN WHEN YOUR EGR BLOWSUP BUY A NEW ONE + 2 X 600.00 HUNDREDOLLAR CAT' S ON EX-HOUSE!PAYMENT+ LABOR? 2002 ESCAPE!@100'000 MILES? wtf! ford! oh lord!
good video