Both heaters dead on the PT Cruiser is often a symptom of a bad (leaking) oil pressure sensor which has pushed oil up the harness and into one of the PCM connectors (right hand one as you are facing it).
Ivan, I just wanted to let you know how much I appreciate what you do and the influence you've had on me and my mechanical endeavors. I have been fighting an intermittent CAN BUS failure on my 05 Volvo V70R for well over a year. It did not occur often and would clear itself like nothing happened on the next start up, or in motion depending on which warning message was present. I could easily lose my instrument cluster and go into a limp mode. While watching you tackle an intermittent Malibu CAN BUS short that turned out to be a transmission cooler line harness rub through, you mentioned that 95% of all these types of problems occurred in the presence of heat and vibration. Even though I felt I had gone through my engine compartment with a fine tooth comb at least a dozen times I thought I'd once again take another look because of what you said. After spending a good two hours hunting around and inspecting/wrapping even the most miniscule of wiring runs, I came across a forward plug connector for my turbo boost pressure sensor. I thought I'd checked every connector in the compartment but that one didn't ring a bell. It sat forward in the nose along with the intercooler. Opened it and found a great deal of corrosion as the individual who had replaced it at some point in the past, lost the weather proof connector surround and plugged it in anyway. This I feel was what I'd been looking for all this time. Have driven for days now and confident that this Gremlin has been dealt with. Again, If it wasn't for you. You have definitely made the difference. Hitting that "Thanks" button and sending along some cabbage for the inspiration. Signed, George in Oregon
Fixing a Chrysler no parts required is a modern day miracle. If that occurs, I’m announcing Ivan the GOAT…..no one fixes a Chrysler anything no parts required.
About 15 years ago I had a 2000 Chevy Astro with a similar problem. The o2 sensors were replaced with Bosch, but heater codes kept returning. After much hair pulling, I finally found the new sensors wouldn't meet the self test parameters progmmed into the pcm (even though the resistance was in spec, and the wiring was perfect). Ironically, it was this case that caused me to buy my first oscilloscope, and to never trust any sensors that aren't made by the original manufacturer (no matter how reputable the brand). Cool video Ivan! Keep 'em coming!
@@PineHollowAutoDiagnostics I now only use what came out in the vehicle new, there's just no way to tell what self test parameters were written in the ecm, or what brands it might play nice with. If it came new with a Bosch I'll put one in it (although it might make me nauseous after that experience 🤢), I run only Denso in my GM vehicles (that's what they came from the factory with).
@PineHollowAutoDiagnostics hey ph scanner danner told me that denso shouldn't be used in chryslers only ntk original and that it might be why I get my p0131 code. Any advice? I'm not getting 12v on that heater wire to my upstream connector with key on.
@@JessClearyAutoRepairLLC I had to warranty an OEM Bosch sensor on a Chevy Cruze turbo 3 TIMES in one month... Finally tried a Denso, worked like a charm 😁👍
I absolutely love the out of the box thinking to feed the heaters directly. This is exactly the way I used to get maximum satisfaction with happy customers and a good feeling of accomplishing something others could not do. I'm now 28 years out of the diagnostic world and miss it greatly. I now build pc's and diagnose faulty pc's, just to sort of keep my hand in.
That's awesome -- I did the opposite and quit PC repair and build for auto. A lot more diag that I initially thought. Hard work but I like it. Minus the OEM programming systems ;)
@@bernardaflores1720 Hi, I could try to, but please remember, I do this at home in my spare time, so I am not the fountain of knowledge on everything pc! But I do love a challenge.
I don't think this is going to work as a permanent solution. It definitely confirms the problem, but from what I understand-- I believe O2 heater strategy is typically to only turn on for a few minutes to help get them going when you first start the car. I could be wrong, but I don't think the heaters are supposed to run all the time. (Think glow plugs on a diesel). I think the heaters will burn out fairly quickly if you just keep them on all th time. But again-- I could be wrong; but think about it-- Why would they even run heaters though the computer if they were going to be on all the time? Why not just tie them to a simple relay?? I think they are driven by the computer because they only turn on in specific situations, such as startup.
Its true the "modern" strategy is to pulse width modulate the heaters after warmup, however the O2 heaters are 100% designed to be on continuously while with engine is running. Many cars from the 90s would just turn on the heaters via a relay during engine operation.
@@baldyslapnut. Any diesel I've ever seen.. It only runs the glow plug for the first 5 or 10 seconds.. and you're supposed to wait until it turns off before you start the engine.. I have a 2002 7.3L F350; but I don't know much about newer diesels than that. I know they have particulate filters now... but other than that, it's out of my pay grade. :)
In new York, the car has to be plugged in, if the emission code is present, even though it's hacked to run right, it still won't pass. This is one wild ,genius work around though! You are amazing! Can't wait for part 2!
My youngest sister had the 2005 version of one of these. Same thing essentially. She absolutely loved it at first, but it spent more time at the dealer than it did in her driveway.
Ivan, have you still got the heater wires connected back to the PCM, if so you could be providing a back feed. This was evident when you first connected the heaters with the ignition OFF and things started to click and buzz. The output of the PCM will most probably be some MOSFETs, these have built in or on the circuit board circuit protection components, they could also be failing. So I would disconnect the PCM feed to the heaters. You are now applying full battery volts to the heaters, the PCM was probably PWM controlling them for a reason, you may find you will shorten the life of the O2 sensors because the heaters are full on all the time or at some driving conditions the engine performance again may suffer. I'm no mechanic, but an electronics engineer in the industrial control field.
Hahaha, nice try Tom, but Ivan is spot on here. You have to have the feedback or the diagnostic faults are set. Would be nice to see the scope activity on known good circuits to see what the duty cycle should be.
@@PineHollowAutoDiagnostics Maybe cut the feed to the PCM and place a large resistor in line to limit current back into the PCM? This way the heaters get power and the PCM gets its feedback (low current)?
Drivers in my 1999 Porsche Boxter were dead for o2 heaters also. Did the same thing fed them with volts and it worked managed to pass emissions. Later down the road the car was sold and few months later I saw the car burned in the area where o2 sensors were. Related ? Maybe 😂 but it did pass emissions 😅
I would think a 5 min timer that cuts the power would be the next step. Only need the heaters to warm them up, otherwise why have a control circuit. Much like we have to have on our radios so the car thinks we are in park watching the movies.
Whenever you are working on a late 90s to early 2000s Chrysler vehicle I hear that door chime and think I'm hearing my Durango's door open on the carport😂 😂
On older OBD II vehicles real time PID data update rates (waveform fidelity) are very limited due to the processing constraints in the ECM. So, the PID waveforms may look distorted. The traditional HEGO (Narrow band) heaters are designed for 12V systems. So, to turn on a heater all you have to do is connect it across +12VDC. From a module design standpoint the common approach is to fuse protect the power feed to the heater and then activate using a smart low side power driver in the ECM. The driver power IC must be smart in order to report load circuit open or circuit short and its own internal health which is a requirement for OBD II. Meaning the HEGO heater circuit has full diagnostic coverage. When the engine and exhaust are up to operating temperature the ECM can reduce the duty cycle from 100% (full on) to 50% or lower, and this heater strategy could be different for the up stream and the down stream HEGOs. If you read the fuel closed loop strategies for systems with a UEGO you will immediately appreciate that open loop fuel strategy to maintain accurate A/F ratio to meet emissions is almost impossible, given the practical engineering approach within ECM cost constraints, which are considerable.
I had a 2006. It was complete junk, but I was desperate for a car at the time. I bought it with an upstream O2 sensor heater circuit code. Turns out it was just a rusty ground on the passenger side frame rail. Fixing that ground also fixed my AC compressor clutch not engaging.
Hey Ivan, always love seeing your new videos come out. Question tho, when modifying a vehicle’s electrical system is there any liability from the modification that needs to be of concern?
Classic Chrysler, my brothers 2006 Chrysler 300 has the same issue. A few years back I bought a pcm out of some place in Florida for him to fix heater circuit codes, and then last year the same exact thing happened again, this time I bought a pcm from flagship one
Re-man PCM on the net. Lifetime warranty. If I remember 300$ appx exchange. All updates included. Replaced it myself in 10 minutes . Dealer price insane. 3 years later runs like a scared rabbit. Dealer close to 2000$ plus.
Ivan, I think you were a bit disingenuous at 18:45. Hahaha . You knew there was a good chance that might work or else you wouldn't have tried it. You are beginning to remind me of "Doc Brown" from "Back to the Future" with all of your creative mods to fix or improve cars. I love it!
Definitely not disingenuous.. it's easy to assume that it would operate the heaters and at least do something. But it wasn't likely or obvious that it would actually trick the computer into not setting any codes and actually stay in closed loop like normal. That was a surprise.. because understand: the drivers inside the computer are still cooked
@@PineHollowAutoDiagnostics Yeah.. I do the same on jobs. lol.. Set expectations low and that it's going to take longer than you need; and then when you get it done early, the customer is always a happy camper..
Ivan has become the wizard of knowing when to end a video. Luckily we only have to wait a day for the conclusion or will we have to wait for part three
I like PT Cruisers. I owned a 2001 and drove it for 14 years!! I just got rid of it about 2 years ago with 200,000 miles on it. I drove it up and down the east coast and out to Indiana several times. It was not a turbo and had horrible gas mileage. Mine always leaked a little water and I could never figure out where it was going. I think they all do. lol
I was offered one cheap. the gas mileage, and the towing capacity made me decline. I can live with the tight space under the hood. Wouldn't like it at every timing belt change, but not a deal breaker.
Does a very interesting way of doing the heater repair on the positive side. How would you have approached the problem, if it was on the negative/ ground side???
You're a brave man Ivan...I thought only Rainman Ray was gullible to work on PT Crusher that are on their way to the junkyard..Some owners will spend crazy money on vehicles not worth fixing. Love is blind.
Placing bets on control arm bushing, sway bar bushings inner and outer, watts links, bell crank, but not the ball joint because you get a new one with control arm every 15K miles give or take a few. Also replace the torn engine pencil struts while you're at it. ...It's a PT thing.
Great creative solution to an expensive problem! I'm curious, though. If turning the heaters on and leaving them on works, why didn't they just power them through a relay to begin with?
This is still from a time where Mopar didn't fuse many components. I would still verify that there aren't any o2 fuses, even though the wiring diagram didn't show them. In any case, the heater circuit is PWM, and they are commanded OFF for a reason! So while you're tricking them now, I think you'll get at least a different code for the heaters being on all the time, perhaps 2 trip code, as time goes on. IMO, 1 of the OE o2s failed, and took out the driver IF the circuit really isn't fused. IMO, it still needs an PCM. As for the frt end, I'm calling lower control arm bushings and stb links ;)
I did a similar thing to trick the secondary air injection on a 01 VW n it went into fuel control all day n stayed in CL but the next morning it came up with a code for being shorted to b positive. Clear n same thing would repeat
Wonder if you can open the PCM up and replace the drivers. Transistors are easy to source and change. I wonder once these cars start getting rare and parts become scarce we might have to change up our game. I've had to change components on boards before so it's not too difficult.
Check PCM powers and grounds. There could be a dedicated O2S heater feed that goes through a fuse. Also, there is possibly a P-channel MOSFET in the PCM responsible for controlling the power to the heater, and the gate of the MOSFET requires a ground. I have a feeling though that the conclusion will be something completely out of left-field that I would never even dream of in a million years.
An issue is that in NYS the vehicle will not pass state emissions inspection with more than one monitor incomplete. NY city may be even more stitch. They give you the one not reset because some evap monitors take forever to complete.
Feels like the O2 heater resistance is too low, and the PCM is complaining about having to supply too much current to them (PCM thinks it's driving a short)? Wonder what the resistance is of a known good OE sensor....
They usually run at 1 amp from what I've seen.. so that would be about 12 ohms.. I think these are only running at 2 amps though, with 6 ohms.. Which is still reasonable. I would check service date to know for sure though.
This is what scanner danner said that the aftermarket oxygen sensor on a chrysler 300, i think it was, was doing this and after he put an ntk sensor it fixed it.
Great test fix! think I would prefer to wire the heaters through a resistor that sets the voltage to about 9 volts so if there is something happening at the output drivers it doesn’t fully fry them out by giving that circuit full battery power. Also it won’t blow the ASD fuse and shut the car down at the least opportune time.
Even if its not the problem, (many) pt cruisers need the ignition key switch replaced about every 100,000 miles. I've had to replace a few of those switches to fix random cel errors and power issues on the pt cruisers. (Power both electrical and performance.)
Pretty sure these PCM's check the O2 sensors after the ignition is off and if the PCM can't run the heaters after shut-down it may be an issue and set a code.
Interestingly enough, on my (and others) 2003 Dodge Dakota, the O2 heaters ARE powered through the ASD relay. I was thinking at the beginning of the video to check the wiring from the ASD relay. So Chrysler had figured that out early on - no separate driver needed for the heaters in the PCM.
What concerns me is why did the cooling fan come on when you supplied 12V to the circuit. Almost sounds like a bad ground or something somewhere. Unless it's somehow back feeding through the computer (can't really see that happening) and kicking it on. Interesting!
@@PineHollowAutoDiagnostics My thought was wiring diagrams wrong, he was probing the fan relay so heater wouldn't get power from that....... Wish I had known you don't need the pico scope to run the software to look at your captures. I would have installed it long ago.
Good video Ivan. I thought that wasn’t going to work but hats off to your persistence. That ECU is probably NLA and getting harder to find used. BTW I was going to purchase a Thinktool Pros through your link but it appears to be NLA as well. I like the graphing feature of this tool over my Autel Ultra which I have kept the software current for the past 3 years. Maybe you can give another recommendation?
Wouldn't the o2 heaters be powered up at all times during driving ? If anything the solder joints in the pcm are damaged but may be repairable ! If not replace the pcm and definitely the engine oil !
Check for recalls, these cars have been known to catch fire while driving do to a power steating hose. It happened to my cousin, the car cought on fire in the engine compartment and the car was totaled.
I have an after market AFR meter on a hot rod. The O2 heater comes on for about thirty seconds at start and turns off then starts reading, the instructions said this was normal.
Did you do isolation checks on the heater citcuits on addition to the continuity checks? I have had lines on csbles shorted to other lines causing iddues similar to this. These sort of problems are frequently intermittent due to corrosion or cracked wiring insulation. Isolation trsts arr tedious but a necessary part of troubleshooting. oting ent
Place your bets now that this car will be fixed? Now, where are you going to find a sucker to take a bet like that? LOL. IIRC these PT cruisers are based on the Neon; not the best car in the world. GREAT VIDEO!
Works but I have no idea how long an O2 heater will last when switched on the entire time the engine is running. If it doesn't last, maybe you could tie a PWM supply to it somehow? I'm not sure about that old Mopar PCM, but we have O2 drivers replaced often in the newer ones. But you know that.
i have a question and it’s just because im curious my aunt used to have a 2002 jeep Cherokee Laredo with the good old straight six engine anyway it’s no longer in are life but i remember if that thing ever had a problem with a senior of any kind it really got to the point of stupid but if it wasn’t from jeep it would never like it it was extremely fussy with 02 sensors and crank sensors you could get away with a lot an very little at the same time now i have had the same issue with our 2003 chevy suburban with mass air sensors and the map sensors really things involved directly with fuel control it’s really picky i used to question the aftermarket stuff for a lot of years pre pandemic you could most of the time get away with not going to the dealer but now i feel i would have better luck at the roulette table in Vegas so is the issue just that there’s just enough of a difference that it doesn’t work if that is all it is we all need to demand better
I can't help but wonder if the ECM is supposed to provide a regulated voltage to the O2 sensor's heater. Fun fact: in the old days, some electronic circuits actually used light bulbs to provide regulation. I've seen it a couple of times. Your use of a light bulb may have been beneficial🤔
Do you think the heaters being constantly on would do anything Ivan? And BTW regarding that E200 i told you about before, i tested APP and TPS , both checked out to be good. The i looked a bit closer, APP data showed 49% at WOT while the car was in drive going uphill! Same sensor would report 93% at WOT in neutral or park, regardless of wether the car is running or not. Would scope the 5v and grounds at the APP sensor and see what's happening to them while in D vs N.
If the heaters are pulse-width controlled, then the 100% duty cycle may have an effect on longevity. I know--longevity and PT cruisers aren't often uttered in the same sentence.
They could be.. I hope he reads through service data.. because I don't think they are supposed to be on all the time. I'm fairly sure that once everything gets up to operating temp.. the heaters shut off. They are really only there to warm up the sensors so that they come online quicker at startup. If he leaves them on all the time, surely they will burn up quickly. Especially if they are PWM and getting essentially 100% duty cycle.. (as you said).
'I know--longevity and PT cruisers aren't often uttered in the same sentence.' Bahahahaha!!!! Isn't that the truth! I've heard more mechanics cuss those things! 🤣
So inhave the same 2 codes.. p0031 and p0037. For low voltage on heater circut. I tested the pins going down on plug c2 same as you with a multimeter meter and they both tested fine like yours. So I went ahead and did this little hack, but now I'm getting p0032 and p0038. Voltage to high. I run a high output alternator and it is set at 14.6v constant. Do you know the voltage they are supposed to be at? Like the range they need to be in for no cel to come on? Cause I can add diodes to decrease the voltage in line with the nee bypass. I'll try to search it, but just thought ild ask.
Why is there somtime pulsing from the pcm seen with the scope? Is the oxigen sensor heater control pulswith commanded? So if the pcm "see" to much current, it shut off the pwm command for the heater? Like a short in the wire to the heater, or heater with to low(or maybe also high?) resistance?
random & off-topic, but where did you get all of your banana-plug test leads & test adapters? is there a set that you bought, or did you just piece together everything? Would you consider doing a video on all of the miscellaneous test leads, adapters, & 'widgets' you use ??? (both the custom-made test stuff & the commercially available stuff you've bought)
Because Ivan was back-feeding power into an ECU power output, which isn't generally a good idea. There will likely be protection diodes between the output pins and a 12v and 0v rail within the PCM in order to suppress voltage transients higher than the 12v rail, or lower than ground (negative voltages). With the key off injecting voltage into outputs like this can cause other parts of the PCM to be powered up.
I think the heaters are not supposed to turn on all the time. They are only there to heat up the sensor at startup so that it comes online quicker.. and then when coolant hits a certain temp.. it will shut them off.. (Or maybe when it goes into closed loop? I'm not exactly sure). So the heater control could be tied to the same strategy as the fan. In other words, when the coolant hits a certain temp-- the fan turns on and those O2 heaters turn off-- since they will be plenty hot already by the exhaust. I hope he reads through service data on the next video so that we can see the exact strategy. I just can't imagine that they heaters run ALL the time. They would burn out fairly quickly, I would think.
That’s pretty much what I was getting at. The heaters can’t be on all the time and the fans can’t be on all the time. Or maybe the climate control was on making the fans run. Hope Ivan explains.
@@stevensutcliffe533 I think he will next video. I bet he looks it up in service data and it explains the dynamic strategy and just leaving it on all the time is not going to work.. (at least I don't think-- I could be wrong. :)
My question is, what is the purpose of having PCM drivers then? To save a few amps? Just so it can detect faults for emissions purposes? As usual, it seems nuts to me to not pop open the computer and see if there is just a simple transistor or something that can be replaced 😅
I don't think the heaters are supposed to be on all the time.. I think the computer only drives them at specific situations, such as at startup.. and once they hit closed loop- they turn off. (I think-- I'm not certain). Maybe he'll ready about the strategy in service data in the next video and we'll know for sure.
Ivan, you mentioned the heater circuit can carry 2 amps when you measured resistance. Is there an equation that tells you amount of current a component can carry based on its resistance? Thanks
Doing the job of the computer makes it happy but will the monitors run for the smog test in new york or will the computer recognize a problem and still not run them ? Npr 👍♦️
Try to remove the heater wires from the ECU and control them. That way you remove the possibility to pass current to sections of the ECU that should be turned off.
Hi! I am tired of part changing mechanics. I am going to do everything myself. I have 2003 a 4.8L 2500 gmc savana Penske 12'. I haven't drove it in 4years no mechanic could get it running . A better mechanic told me change the crank shaft sensor i did myself the van started running. I want to fix it myself with your help so what to do next. Oh by the way they cut my resonator and catalytic. What to do next?
Customer complaint? "I own a Chrysler." Ivan, "enough said"! 🤣
Customer complaint - It's a PT Loser 🙁
Both heaters dead on the PT Cruiser is often a symptom of a bad (leaking) oil pressure sensor which has pushed oil up the harness and into one of the PCM connectors (right hand one as you are facing it).
Very interesting. Didn't see any oil at the PCM...
Ivan,
I just wanted to let you know how much I appreciate what you do and the influence you've had on me and my mechanical endeavors. I have been fighting an intermittent CAN BUS failure on my 05 Volvo V70R for well over a year. It did not occur often and would clear itself like nothing happened on the next start up, or in motion depending on which warning message was present. I could easily lose my instrument cluster and go into a limp mode. While watching you tackle an intermittent Malibu CAN BUS short that turned out to be a transmission cooler line harness rub through, you mentioned that 95% of all these types of problems occurred in the presence of heat and vibration. Even though I felt I had gone through my engine compartment with a fine tooth comb at least a dozen times I thought I'd once again take another look because of what you said. After spending a good two hours hunting around and inspecting/wrapping even the most miniscule of wiring runs, I came across a forward plug connector for my turbo boost pressure sensor. I thought I'd checked every connector in the compartment but that one didn't ring a bell. It sat forward in the nose along with the intercooler.
Opened it and found a great deal of corrosion as the individual who had replaced it at some point in the past, lost the weather proof connector surround and plugged it in anyway. This I feel was what I'd been looking for all this time. Have driven for days now and confident that this Gremlin has been dealt with.
Again, If it wasn't for you. You have definitely made the difference. Hitting that "Thanks" button and sending along some cabbage for the inspiration.
Signed,
George in Oregon
Fixing a Chrysler no parts required is a modern day miracle. If that occurs, I’m announcing Ivan the GOAT…..no one fixes a Chrysler anything no parts required.
Haha Chryslers can be picky!
I’ll probably regret this, but what is a GOAT?
@@brianw8963 Greatest Of All Time. Used to mean someone you blamed something bad on years ago but the acronym took over in the past 20 years
I imagine it’s the only way to fix it. I’d wager there’s no parts available for these turds.
@@htownblue11 Ok, Thank You. I knew what Goats were back in my glory days, and pretty familiar with the hairy critters. Old dog still learning. 👍👍🇺🇸
About 15 years ago I had a 2000 Chevy Astro with a similar problem. The o2 sensors were replaced with Bosch, but heater codes kept returning. After much hair pulling, I finally found the new sensors wouldn't meet the self test parameters progmmed into the pcm (even though the resistance was in spec, and the wiring was perfect). Ironically, it was this case that caused me to buy my first oscilloscope, and to never trust any sensors that aren't made by the original manufacturer (no matter how reputable the brand). Cool video Ivan! Keep 'em coming!
Bosch sensors suck... Denso is much more reliable 👍
@@PineHollowAutoDiagnostics I now only use what came out in the vehicle new, there's just no way to tell what self test parameters were written in the ecm, or what brands it might play nice with. If it came new with a Bosch I'll put one in it (although it might make me nauseous after that experience 🤢), I run only Denso in my GM vehicles (that's what they came from the factory with).
@PineHollowAutoDiagnostics hey ph scanner danner told me that denso shouldn't be used in chryslers only ntk original and that it might be why I get my p0131 code. Any advice? I'm not getting 12v on that heater wire to my upstream connector with key on.
I watched a one hour video changing the spark plugs on one of those. Now THAT is worth paying the extra for the expensive plugs.
@@JessClearyAutoRepairLLC I had to warranty an OEM Bosch sensor on a Chevy Cruze turbo 3 TIMES in one month... Finally tried a Denso, worked like a charm 😁👍
I absolutely love the out of the box thinking to feed the heaters directly. This is exactly the way I used to get maximum satisfaction with happy customers and a good feeling of accomplishing something others could not do.
I'm now 28 years out of the diagnostic world and miss it greatly.
I now build pc's and diagnose faulty pc's, just to sort of keep my hand in.
Can you answer a PC question??
That's awesome -- I did the opposite and quit PC repair and build for auto. A lot more diag that I initially thought. Hard work but I like it. Minus the OEM programming systems ;)
@@bernardaflores1720 Hi, I could try to, but please remember, I do this at home in my spare time, so I am not the fountain of knowledge on everything pc! But I do love a challenge.
lol! The childlike enthusiasm on your face as you discover the ‘no parts’ fix is priceless, Ivan! Very creative!
I don't think this is going to work as a permanent solution. It definitely confirms the problem, but from what I understand-- I believe O2 heater strategy is typically to only turn on for a few minutes to help get them going when you first start the car. I could be wrong, but I don't think the heaters are supposed to run all the time. (Think glow plugs on a diesel). I think the heaters will burn out fairly quickly if you just keep them on all th time. But again-- I could be wrong; but think about it-- Why would they even run heaters though the computer if they were going to be on all the time? Why not just tie them to a simple relay?? I think they are driven by the computer because they only turn on in specific situations, such as startup.
Its true the "modern" strategy is to pulse width modulate the heaters after warmup, however the O2 heaters are 100% designed to be on continuously while with engine is running. Many cars from the 90s would just turn on the heaters via a relay during engine operation.
12v when the engine is (or was) running is the normal setup for 3/4 wire upstream O2 heaters, often with a feed directly off the alternator.
I think glow plugs in modern diesels are pulsed throughout the duty cycle to optimise cylinder temps for more efficient combustion.
@@baldyslapnut. Any diesel I've ever seen.. It only runs the glow plug for the first 5 or 10 seconds.. and you're supposed to wait until it turns off before you start the engine.. I have a 2002 7.3L F350; but I don't know much about newer diesels than that. I know they have particulate filters now... but other than that, it's out of my pay grade. :)
In new York, the car has to be plugged in, if the emission code is present, even though it's hacked to run right, it still won't pass. This is one wild ,genius work around though! You are amazing! Can't wait for part 2!
But he's saying the code doesn't come back
Places like that are why they invented the USB killer. Move the can bus pins and put one on the pins old location. Make their scanner smoke.
My youngest sister had the 2005 version of one of these. Same thing essentially. She absolutely loved it at first, but it spent more time at the dealer than it did in her driveway.
Good to know may get someone home someday !
Sharp Ivan !!!
Awesome. I'm impressed, you don't see talent like that very often these days. 👍
Thanks!
Wow thank YOU!
Ray loves these😂 he may have a computer...
RainManRay. Pretty sure he has a few in the yard, and tried swapping ECMs on a couple.
Ivan, have you still got the heater wires connected back to the PCM, if so you could be providing a back feed.
This was evident when you first connected the heaters with the ignition OFF and things started to click and buzz.
The output of the PCM will most probably be some MOSFETs, these have built in or on the circuit board circuit protection components, they could also be failing.
So I would disconnect the PCM feed to the heaters.
You are now applying full battery volts to the heaters, the PCM was probably PWM controlling them for a reason, you may find you will shorten the life of the O2 sensors because the heaters are full on all the time or at some driving conditions the engine performance again may suffer.
I'm no mechanic, but an electronics engineer in the industrial control field.
Another electrical engineer here... this poster is 100% correct with what was written.
If you cut wires to the PCM it will instantly set the same codes and run in open loop so that is not an option 😉
Hahaha, nice try Tom, but Ivan is spot on here. You have to have the feedback or the diagnostic faults are set. Would be nice to see the scope activity on known good circuits to see what the duty cycle should be.
Still great things to discuss!
The only stupid question/statement is the one never said!
Iron sharpening iron!
@@PineHollowAutoDiagnostics
Maybe cut the feed to the PCM and place a large resistor in line to limit current back into the PCM? This way the heaters get power and the PCM gets its feedback (low current)?
Drivers in my 1999 Porsche Boxter were dead for o2 heaters also. Did the same thing fed them with volts and it worked managed to pass emissions. Later down the road the car was sold and few months later I saw the car burned in the area where o2 sensors were. Related ? Maybe 😂 but it did pass emissions 😅
Car was burned? 😳
I would think a 5 min timer that cuts the power would be the next step. Only need the heaters to warm them up, otherwise why have a control circuit. Much like we have to have on our radios so the car thinks we are in park watching the movies.
u can use timer relay. like turn off heater after 3 mins.
Excellent job ! That investigative / researching attitude of yours is beyond beneficial - it is a life lesson !!
👊🏼 🔥 💻 📈 🥇
Whenever you are working on a late 90s to early 2000s Chrysler vehicle I hear that door chime and think I'm hearing my Durango's door open on the carport😂 😂
These PT's are fun to put in a new timing belt kit.
On older OBD II vehicles real time PID data update rates (waveform fidelity) are very limited due to the processing constraints in the ECM. So, the PID waveforms may look distorted.
The traditional HEGO (Narrow band) heaters are designed for 12V systems. So, to turn on a heater all you have to do is connect it across +12VDC. From a module design standpoint the common approach is to fuse protect the power feed to the heater and then activate using a smart low side power driver in the ECM. The driver power IC must be smart in order to report load circuit open or circuit short and its own internal health which is a requirement for OBD II. Meaning the HEGO heater circuit has full diagnostic coverage.
When the engine and exhaust are up to operating temperature the ECM can reduce the duty cycle from 100% (full on) to 50% or lower, and this heater strategy could be different for the up stream and the down stream HEGOs.
If you read the fuel closed loop strategies for systems with a UEGO you will immediately appreciate that open loop fuel strategy to maintain accurate A/F ratio to meet emissions is almost impossible, given the practical engineering approach within ECM cost constraints, which are considerable.
I had a 2006. It was complete junk, but I was desperate for a car at the time. I bought it with an upstream O2 sensor heater circuit code. Turns out it was just a rusty ground on the passenger side frame rail. Fixing that ground also fixed my AC compressor clutch not engaging.
I have a pesky p0131 on my 2005 chrysler pacifica was this your code? I don't think my grounds are bad because at the o2 harness I get ground well.
Can't wait for part 2, this would have been pretty difficult for me to solo. I'm hooked
I love that scan tool just updated mine for the next 2yrs
I hate it when he leaves us all hanging!! ;-) Luv U man.
Hey Ivan, always love seeing your new videos come out. Question tho, when modifying a vehicle’s electrical system is there any liability from the modification that needs to be of concern?
Classic Chrysler, my brothers 2006 Chrysler 300 has the same issue. A few years back I bought a pcm out of some place in Florida for him to fix heater circuit codes, and then last year the same exact thing happened again, this time I bought a pcm from flagship one
That is unbelievable indeed I'm glad that fixed the car
Re-man PCM on the net. Lifetime warranty. If I remember 300$ appx exchange. All updates included. Replaced it myself in 10 minutes . Dealer price insane. 3 years later runs like a scared rabbit. Dealer close to 2000$ plus.
Ivan, I think you were a bit disingenuous at 18:45. Hahaha . You knew there was a good chance that might work or else you wouldn't have tried it. You are beginning to remind me of "Doc Brown" from "Back to the Future" with all of your creative mods to fix or improve cars. I love it!
Russian ingenuity!
Definitely not disingenuous.. it's easy to assume that it would operate the heaters and at least do something. But it wasn't likely or obvious that it would actually trick the computer into not setting any codes and actually stay in closed loop like normal. That was a surprise.. because understand: the drivers inside the computer are still cooked
Actually I assumed it would NOT work... Saves disappointment down the road 😂
@@PineHollowAutoDiagnostics Yeah.. I do the same on jobs. lol.. Set expectations low and that it's going to take longer than you need; and then when you get it done early, the customer is always a happy camper..
Ivan has become the wizard of knowing when to end a video. Luckily we only have to wait a day for the conclusion or will we have to wait for part three
I like PT Cruisers. I owned a 2001 and drove it for 14 years!! I just got rid of it about 2 years ago with 200,000 miles on it. I drove it up and down the east coast and out to Indiana several times. It was not a turbo and had horrible gas mileage. Mine always leaked a little water and I could never figure out where it was going. I think they all do. lol
I was offered one cheap. the gas mileage, and the towing capacity made me decline. I can live with the tight space under the hood. Wouldn't like it at every timing belt change, but not a deal breaker.
5:39 I had a 2012 Hyundai Veracruz in my shop that when you hit bumps ,had a bad CV Shaft that sounded exactly like that! Great video Ivan❤
Number 1 Russian hack of the year!!! Very nice
Does a very interesting way of doing the heater repair on the positive side. How would you have approached the problem, if it was on the negative/ ground side???
You're a brave man Ivan...I thought only Rainman Ray was gullible to work on PT Crusher that are on their way to the junkyard..Some owners will spend crazy money on vehicles not worth fixing. Love is blind.
Placing bets on control arm bushing, sway bar bushings inner and outer, watts links, bell crank, but not the ball joint because you get a new one with control arm every 15K miles give or take a few. Also replace the torn engine pencil struts while you're at it. ...It's a PT thing.
Great creative solution to an expensive problem! I'm curious, though. If turning the heaters on and leaving them on works, why didn't they just power them through a relay to begin with?
This is still from a time where Mopar didn't fuse many components. I would still verify that there aren't any o2 fuses, even though the wiring diagram didn't show them. In any case, the heater circuit is PWM, and they are commanded OFF for a reason! So while you're tricking them now, I think you'll get at least a different code for the heaters being on all the time, perhaps 2 trip code, as time goes on. IMO, 1 of the OE o2s failed, and took out the driver IF the circuit really isn't fused. IMO, it still needs an PCM. As for the frt end, I'm calling lower control arm bushings and stb links ;)
I did a similar thing to trick the secondary air injection on a 01 VW n it went into fuel control all day n stayed in CL but the next morning it came up with a code for being shorted to b positive. Clear n same thing would repeat
I love your channel. You're the motor detective of engines
Wonder if you can open the PCM up and replace the drivers. Transistors are easy to source and change. I wonder once these cars start getting rare and parts become scarce we might have to change up our game. I've had to change components on boards before so it's not too difficult.
I was like you and didn't expect the results with the test light.
Thanks for the video Ivan.
Check PCM powers and grounds. There could be a dedicated O2S heater feed that goes through a fuse. Also, there is possibly a P-channel MOSFET in the PCM responsible for controlling the power to the heater, and the gate of the MOSFET requires a ground. I have a feeling though that the conclusion will be something completely out of left-field that I would never even dream of in a million years.
An issue is that in NYS the vehicle will not pass state emissions inspection with more than one monitor incomplete. NY city may be even more stitch. They give you the one not reset because some evap monitors take forever to complete.
Nice discovery, The ECM rebuilder's probably won't like it. 😁👍
Feels like the O2 heater resistance is too low, and the PCM is complaining about having to supply too much current to them (PCM thinks it's driving a short)? Wonder what the resistance is of a known good OE sensor....
They usually run at 1 amp from what I've seen.. so that would be about 12 ohms.. I think these are only running at 2 amps though, with 6 ohms.. Which is still reasonable. I would check service date to know for sure though.
PCM didn't even TRY to turn on the heaters though...
This is what scanner danner said that the aftermarket oxygen sensor on a chrysler 300, i think it was, was doing this and after he put an ntk sensor it fixed it.
Great test fix! think I would prefer to wire the heaters through a resistor that sets the voltage to about 9 volts so if there is something happening at the output drivers it doesn’t fully fry them out by giving that circuit full battery power. Also it won’t blow the ASD fuse and shut the car down at the least opportune time.
I was thinking 5 volts honestly I think either would work
Even if its not the problem, (many) pt cruisers need the ignition key switch replaced about every 100,000 miles.
I've had to replace a few of those switches to fix random cel errors and power issues on the pt cruisers.
(Power both electrical and performance.)
u can use timer relay. like turn off heater after 3 mins.
What the heck let’s give it a try! So cool. 👍👍🇺🇸
Front sway bar bushings.
Pretty sure these PCM's check the O2 sensors after the ignition is off and if the PCM can't run the heaters after shut-down it may be an issue and set a code.
Interesting. New York has vehicle inspections so will this optional repair pass inspection?
Interestingly enough, on my (and others) 2003 Dodge Dakota, the O2 heaters ARE powered through the ASD relay. I was thinking at the beginning of the video to check the wiring from the ASD relay. So Chrysler had figured that out early on - no separate driver needed for the heaters in the PCM.
What concerns me is why did the cooling fan come on when you supplied 12V to the circuit. Almost sounds like a bad ground or something somewhere. Unless it's somehow back feeding through the computer (can't really see that happening) and kicking it on. Interesting!
I think Ivan's starting to focus on relays?
That was with the key OFF, backfeed through the PCM 👍
@@PineHollowAutoDiagnostics My thought was wiring diagrams wrong, he was probing the fan relay so heater wouldn't get power from that.......
Wish I had known you don't need the pico scope to run the software to look at your captures. I would have installed it long ago.
Good video Ivan. I thought that wasn’t going to work but hats off to your persistence. That ECU is probably NLA and getting harder to find used. BTW I was going to purchase a Thinktool Pros through your link but it appears to be NLA as well. I like the graphing feature of this tool over my Autel Ultra which I have kept the software current for the past 3 years. Maybe you can give another recommendation?
Any Launch or Topdon scanner will have the same software 😉👍
Can’t wait to see what happens with the turbo
Wouldn't the o2 heaters be powered up at all times during driving ? If anything the solder joints in the pcm are damaged but may be repairable ! If not replace the pcm and definitely the engine oil !
Check for recalls, these cars have been known to catch fire while driving do to a power steating hose.
It happened to my cousin, the car cought on fire in the engine compartment and the car was totaled.
I have an after market AFR meter on a hot rod. The O2 heater comes on for about thirty seconds at start and turns off then starts reading, the instructions said this was normal.
ooks like will not hold for long, my guess is code setting will come when monitor ends the test cycle. the car needs a new ecm
looks like will not hold for long, my guess is code setting will come when monitor ends the test cycle. the car needs a new ecm
setting
did you just reinvent the wheel great work
No offense to the owner, but I really feel sick when I see this car on the road😂
Thanks again Ivan
Did you do isolation checks on the heater citcuits on addition to the continuity checks? I have had lines on csbles shorted to other lines causing iddues similar to this. These sort of problems are frequently intermittent due to corrosion or cracked wiring insulation. Isolation trsts arr tedious but a necessary part of troubleshooting.
oting
ent
I wonder? ? ? Why did the rad fans turned on in the first tests ? ? ? 🤔
Did I miss Ivan checking powers and earths of the pcm?
If the 02 sensors short and pops fuse then no fuel pump? Just a thought or did I miss a step?
That’s a concern of mine too
Thanks Ivan!
Place your bets now that this car will be fixed? Now, where are you going to find a sucker to take a bet like that? LOL. IIRC these PT cruisers are based on the Neon; not the best car in the world. GREAT VIDEO!
You are correct. It is a stylized Neon.
Works but I have no idea how long an O2 heater will last when switched on the entire time the engine is running. If it doesn't last, maybe you could tie a PWM supply to it somehow? I'm not sure about that old Mopar PCM, but we have O2 drivers replaced often in the newer ones. But you know that.
This is great as "proof of concept" but the proper fix is to repair or replace the PCM. Is there a service to test and repair such modules?
Normally, a PT Screwer with 135k miles and a bad PCM would and should go to the crusher, but Ivan saved this one!
i have a question and it’s just because im curious my aunt used to have a 2002 jeep Cherokee Laredo with the good old straight six engine anyway it’s no longer in are life but i remember if that thing ever had a problem with a senior of any kind it really got to the point of stupid but if it wasn’t from jeep it would never like it it was extremely fussy with 02 sensors and crank sensors you could get away with a lot an very little at the same time now i have had the same issue with our 2003 chevy suburban with mass air sensors and the map sensors really things involved directly with fuel control it’s really picky i used to question the aftermarket stuff for a lot of years pre pandemic you could most of the time get away with not going to the dealer but now i feel i would have better luck at the roulette table in Vegas so is the issue just that there’s just enough of a difference that it doesn’t work if that is all it is we all need to demand better
I can't help but wonder if the ECM is supposed to provide a regulated voltage to the O2 sensor's heater. Fun fact: in the old days, some electronic circuits actually used light bulbs to provide regulation. I've seen it a couple of times. Your use of a light bulb may have been beneficial🤔
Nice hack!
Why running power to the heaters all the time...... It should be turning on while engine worming up till CL state... Am I right?
Ivan you're goat in auto diag
NEW YORK CITY!?!??!!??!!! sorry. couldn't resist
commifornia car. Would be funny he moved to NYC so he could buy a cat in flyover country.
Do you think the heaters being constantly on would do anything Ivan?
And BTW regarding that E200 i told you about before, i tested APP and TPS , both checked out to be good. The i looked a bit closer, APP data showed 49% at WOT while the car was in drive going uphill! Same sensor would report 93% at WOT in neutral or park, regardless of wether the car is running or not.
Would scope the 5v and grounds at the APP sensor and see what's happening to them while in D vs N.
So the pcm does not send the 12V to the heaters. Why is that?
17% throttle during idle... How dirty is the TB?
Genuine McGyver 😊😊
Last piece of crap PT i worked on the cooling fans ran on high as soon as you turned the key on ECU fixed that issue
Nice trick ivan!.
But i assume it will just work fine
I G sway bar bushings.
If the heaters are pulse-width controlled, then the 100% duty cycle may have an effect on longevity. I know--longevity and PT cruisers aren't often uttered in the same sentence.
They could be.. I hope he reads through service data.. because I don't think they are supposed to be on all the time. I'm fairly sure that once everything gets up to operating temp.. the heaters shut off. They are really only there to warm up the sensors so that they come online quicker at startup. If he leaves them on all the time, surely they will burn up quickly. Especially if they are PWM and getting essentially 100% duty cycle.. (as you said).
@@calholli heaters never shut off completely during operation, just duty cycle is reduced to maybe 50% 👍
'I know--longevity and PT cruisers aren't often uttered in the same sentence.'
Bahahahaha!!!! Isn't that the truth! I've heard more mechanics cuss those things! 🤣
Fix it right!!! New ECM!!!
So inhave the same 2 codes.. p0031 and p0037. For low voltage on heater circut. I tested the pins going down on plug c2 same as you with a multimeter meter and they both tested fine like yours. So I went ahead and did this little hack, but now I'm getting p0032 and p0038. Voltage to high. I run a high output alternator and it is set at 14.6v constant. Do you know the voltage they are supposed to be at? Like the range they need to be in for no cel to come on? Cause I can add diodes to decrease the voltage in line with the nee bypass. I'll try to search it, but just thought ild ask.
Why is there somtime pulsing from the pcm seen with the scope? Is the oxigen sensor heater control pulswith commanded? So if the pcm "see" to much current, it shut off the pwm command for the heater? Like a short in the wire to the heater, or heater with to low(or maybe also high?) resistance?
random & off-topic, but where did you get all of your banana-plug test leads & test adapters? is there a set that you bought, or did you just piece together everything? Would you consider doing a video on all of the miscellaneous test leads, adapters, & 'widgets' you use ??? (both the custom-made test stuff & the commercially available stuff you've bought)
It's a mixed bag lol
I don't understand how it started pulsing the signal.
Question: If the Heater circut on that O2 Sensor is always ON, won´t that burn up the Sensor on Highway drives because of overheating?
Is the cooling fan running constantly now? Why did it come on when power was supplied to o2 heater circuit ?
Because Ivan was back-feeding power into an ECU power output, which isn't generally a good idea. There will likely be protection diodes between the output pins and a 12v and 0v rail within the PCM in order to suppress voltage transients higher than the 12v rail, or lower than ground (negative voltages). With the key off injecting voltage into outputs like this can cause other parts of the PCM to be powered up.
I think the heaters are not supposed to turn on all the time. They are only there to heat up the sensor at startup so that it comes online quicker.. and then when coolant hits a certain temp.. it will shut them off.. (Or maybe when it goes into closed loop? I'm not exactly sure). So the heater control could be tied to the same strategy as the fan. In other words, when the coolant hits a certain temp-- the fan turns on and those O2 heaters turn off-- since they will be plenty hot already by the exhaust. I hope he reads through service data on the next video so that we can see the exact strategy. I just can't imagine that they heaters run ALL the time. They would burn out fairly quickly, I would think.
That’s pretty much what I was getting at. The heaters can’t be on all the time and the fans can’t be on all the time. Or maybe the climate control was on making the fans run. Hope Ivan explains.
@@stevensutcliffe533 I think he will next video. I bet he looks it up in service data and it explains the dynamic strategy and just leaving it on all the time is not going to work.. (at least I don't think-- I could be wrong. :)
My question is, what is the purpose of having PCM drivers then? To save a few amps? Just so it can detect faults for emissions purposes? As usual, it seems nuts to me to not pop open the computer and see if there is just a simple transistor or something that can be replaced 😅
I don't think the heaters are supposed to be on all the time.. I think the computer only drives them at specific situations, such as at startup.. and once they hit closed loop- they turn off. (I think-- I'm not certain). Maybe he'll ready about the strategy in service data in the next video and we'll know for sure.
Ivan, you mentioned the heater circuit can carry 2 amps when you measured resistance. Is there an equation that tells you amount of current a component can carry based on its resistance? Thanks
Ohms law
Ohms law. U=R*I and P=U*I.
Thanks guys!
12 volts divided by 6 ohms he measured with multimeter is 2 amps. But real current may be a little bit lower, as heated it may have bigger resistance.
Doing the job of the computer makes it happy but will the monitors run for the smog test in new york or will the computer recognize a problem and still not run them ?
Npr 👍♦️
Try to remove the heater wires from the ECU and control them. That way you remove the possibility to pass current to sections of the ECU that should be turned off.
Then it will kick the check engine light again and have the same issue..
@@rickybobby7326 Maybe "feed" the ECU via 100 Ohm 2 watt resistors to keep it happy?
Hi! I am tired of part changing mechanics. I am going to do everything myself. I have 2003 a 4.8L 2500 gmc savana Penske 12'. I haven't drove it in 4years no mechanic could get it running . A better mechanic told me change the crank shaft sensor i did myself the van started running. I want to fix it myself with your help so what to do next. Oh by the way they cut my resonator and catalytic. What to do next?