How to test a coolant temperature sensor (ECT sensor test)
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- Опубликовано: 9 июл 2024
- This same test can be followed for both 2 and 3 wire coolant temp. sensors and applies to ALL cars, not just the one in this video (Hyundai Santa Fe)
For more information on this topic, I have written a “field manual” called Engine Performance Diagnostics which is available at www.scannerdanner.com as an eBook or paper book.
Want even more diagnostic training? Whether you are a DIY trying to fix your own car, someone looking to become an auto technician, or a current auto technician that wants to get more into diagnostics, subscribe to ScannerDanner Premium www.scannerdanner.com/join-sc... There is a 14 day free trial.
On ScannerDanner Premium I will bring you right into my classroom at Rosedale Technical College. You will find page for page lectures taken right from my book as well as exclusive classroom type case studies. What is so special about these classroom case studies? I pull live problem vehicles directly into my classroom and we troubleshoot them in real time, using and applying the theory and testing procedures we learn during the classroom lectures. There is no better on-line training of how to troubleshoot automotive electrical and electronics systems anywhere!
Disclaimer:
Due to factors beyond the control of ScannerDanner LLC, it cannot guarantee against unauthorized modifications of this information, or improper use of this information. ScannerDanner LLC assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. ScannerDanner LLC recommends safe practices when working with power tools, automotive lifts, lifting tools, jack stands, electrical equipment, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this video. Due to factors beyond the control of ScannerDanner LLC, no information contained in this video shall create any express or implied warranty or guarantee of any particular result. Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained in this video is the sole responsibility of the user and not ScannerDanner LLC. 
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This was the most fun I've had watching repair videos all week.
Had no idea idle speed was so dependent on the coolant temp! Always assumed that once you get above ~100F the idle just goes to 800rpm...Great demo and explanation.
Know this is old video but turns out a 92 tercel is similar and makes a terrible idle
I had the same idle problem with the Piaggio MP3 400 scooter.
So grateful for the extra effort Paul! I looked this tonight up bc I have the exact same car at Car Care Ministry with ECT & IAT stuck high around 250 & 200 respectively connected and disconnected! Anyway just wanted to say thanks for all the great videos and the hard work you put into them.
Fantastic video. Really makes me appreciate you guys understanding and maintaining the cars of today. THANKS!
Thanks for the video Paul. That engine sounds like it's knocking.
Enjoyed watching this on my lunch break
Thanks my good Man i like it when you expiante the reasoning of diagnoses make me smarter
Great video as usual. I try to use the component test part of this scanner because it gives great info.
Playing with my new Xtool D7. Troubleshooting high idle when in closed loop. Your approach was excellent and the ECT was showing -40. Tested the sensor and it was open. Confirmed good wiring. It took longer to get to parts store and back than to install the fix. If you are ever in southern New Hampshire, dinner is on me.
Man I wish I would have had you for my driveability instructor when I was in school-Great vids!!!!
john james thanks John!
ScannerDanner I been watching ur vedeos all in general specially the networking, cuz I think is the most accurate diagnosis for vehicles now days. my question is or do u have a book that u show the method how to use the scantool with the wave forms?
another great video thank you. I have learned a lot from your video's. keep up the good work .
I'm Highly rated Auto Electrician but All of these coz of your RUclips channel ❤❤❤
Perfect! Loved it 😊 ...... looking cool with the shades...keep it up
a day after watchin your wiring schematic video i fixed my laundry dryer haha i didnt realize that info was universal with ovens n dryers, washing machines.. maybe even power tools? it totally blew my mind.
+justin g that is so awesome! can you post that to my website? www.scannerdanner.com/customer/feedback#add-comment
Good video an info as always thank you and cheers.
superb video and great knowledge as always
wanted to see you do the other 2 cars.loved it
Well done, right to the point.
fantastic video once again
Thanks man, that explains why I was getting same readings on my Chevy using factory mode, thought it was the wiring, have to do test again, thanks a lot
Awesome. Glad this helped. Substituted values can be very misleading
Thank you so much it was a very useful video ❤
enjoy your videos, thanks...
Thank u Paul helped a lot
Terrific video on the CTS analysis and diagnosis!
Now I have to find in section 18 of your book how to do the same electrical delivery test on my injectors as there may be corrosion in the ten year old connectors that is having an impact on voltage delivery at higher rpms. Mechanically they are fine. Edit add: after reading chapter 18 it looks like I need a scope to read voltage input to injector wave forms. Bummer. Looks like I am in for a visual inspection of the wire leads in each injector connector.
GOLD AGAIN!
love this guy tons of info
+david snyder thanks david!
17:26 Just a slight correction the gauge ECT sensor and the PCM ECT sensor don't share the same ground path.
The gauge CT thermistor is grounded through the threads like many dedicated dash temperature sensors are. Only the PCM thermistor uses the dedicated ground wire.
Manufacturers tend to use single wire temp sensors where the output voltage isn't that critical.
***** good catch on that my friend. I have seen them share this ground but in this case you are correct. Thanks!
I have one with a cooling fan kicking on at 255*F and kicking off at 240*F on the scanner data. I spent too much time attempting to locate the known good signature for cooling fan operation until I finally went to unplug the cyl temp sensor to check for open vs shorted to find the sensor was snapped at the base.
Good video
I had a similar problem on my 2000 escalade the scanner under the factory mode it would not close loop at all but on the obd2 it did close loop which was really confusing me lol. good video.
good video. tech. exselente
Any suggestions for a 2003 jeep liberty 3.7L v6 4x4 With the exhaust smoking white for about 5-10 minutes while warming up? Engine has no rod knocks or anything there was a misfire(Changed the coil pack and spark plug) Also replaced breather inlets right and left side and the pcv valve could it be a head gasket seal or a cat converter?
Usually with sensors like that are 5 volts and have negative coefficient thermistors they decrease in resistance and voltage goes down but I like the way you diagnose
that is correct, cold = high resistance and voltage and both will drop as the sensor warms up
Awesome!
Just out of curiosity, how is the scanner screen hooked to the camera as we can see both the scanner and you manipulating it in the same shot? That is so cool!!!
Can a bad temp sensor cause p0171 and p0174? My fan kicks on when its cold and the engine studers. The rpms fluctuate when cruising and the motor has stalled when at idle
Hi Paul this content should be only on premium it's too good to stay here. I mean you've taken time out to help us when you've got two other jobs waiting. You are singlehandedly keeping us fixing and I for one want to pay you
Thanks so much! I do need to show people that I know what I'm doing, so I have to post these here too. But I really appreciate your comment and your support. Merry Christmas!
I did a explorer last week that was a no start sometimes. It was a bad ECT sensor and a stuck lean O2 sensor making the ecu to flood the engine, The shop put a complete tune up on it Over 200 bucks for a fuel pump and changed the computer. They thought I was God when I fixed it. Lol
I Love My Job
Nice!
hi buddy do you have a video showing how to test a draining battery.....i always wathc your video coz its helping me a lot....i learned so much from your videos...thanks....
I do. Thank you!
ruclips.net/user/edit?o=U&video_id=h06xb6SC7Yc
ruclips.net/user/edit?o=U&video_id=dgvIicgZRcQ
ruclips.net/user/edit?o=U&video_id=AA-vHbE1IA8
thanks
Awesome demonstration on substituted values. Hum " online engine performance class" didn't know about this, I know about the premium RUclips channel. Paul what's the online class all about ?
One in the same brother
I went through the last version before the new uploads on the premium channel following the book. I can tell you it's worth it. I've been working in the field for more years than I care to admit and do mobile diagnostics on the side. It's made my job a lot easier. I highly recommend subscribing! Paul, if you're reading this is love to see just a section on scope tips/tricks etc.
Nice job Paul.I am thinking that the fans are controlled by yet another sensor Honda did that for a long time.
I remember seeing 3 ECT-like sensors tapped into water passages on the 1st gen Honda CR-V engine and wondering, until I found out they were ECT, Fan switch and gauge thermistor. Completely different circuits, only united by what they measure (coolant temperature).
Hello , i need to find out where is located the Coolant Temperature Sensor in a 2008 Hyundai Accent , if you guys have an idea please let me know , greetings
Why didn't the code show up on the shops scanner? The coolant sensor effects a lot of things.
Critical Battery. You should change your battery or switch to outlet power immediately to keep from losing your work.
Was interesting to see how much the coolant temp effects idle.
Hi Paul is the unplug it test and grounding of the ref/sig wire applicable to all ECTs ?
+martinguitarhd28 yes! for all thermistor circuits, not just ECTs
coolant temperature sensor and cooling fan switch are this on some vehicles combine or they all are separated like a 2003 Honda Accord has a switch on the radiator and a sensor in the engine.
i have the same in my bmw ,no dtc on scantool ,but at cold engine idle is up and down like crazy ,as soon engine warmed up i have steady idle !
Help! I have a 2008 jeep JKU 3.8
I've replaced my coolant temp sensor twice. I have P2181 and P0118. My gauge doesn't always work and when it does it's not always accurate. It usually only works with the engine off/key on.
Should I be looking at my PCM or wiring harness?
Have you checked pin fitment/ corrosion on the connections. its pretty common on jeeps, especially if they go off-road splashing muddy water. Some aftermarket sensors suck right out of the box too.
ʇɥƃᴉɹlɐ ʇou ɯᴉ. I figured it out. Broken wire in the wiring harness. Thankyou.
Not that it is a big deal and I wanted to let you know either way. At 3:28 you said keep an eye on the desired idle rpm and your logo and website both cover up that PID. I know you move it a little later in the video and you can see it again. I'm not even sure if you can move any of that without having the original video file. As always, thank you for what you do and I am looking forward to meeting you at ASTE this year!
Thanks I'm guessing the signal range to the guage is (-40)+(284) or 324 Fahrenheit degrees when the 5volt signal is grounded.
Sorry im late for class, My bicycle had a plat tire.
Knocking could and does cause sensor failure.
I would strongly recommend a new engine with the replacement of the ECT
Imagine getting the ECT sensor replaced and thinking you could drive it like normal again without the threat of over/under heating.
But wondering if you can make it down the pike without loosing a rod and spewing sh mew.
Scanner Danner, Please Help me, I went to a gm garage & they told me that they do not sell a voltage dropping solonoid for a 07 pontiac G5? The cooling fan (just 1 fan) will not run regardless of temp. I realized yesterday that it was missing a relay & replaced it yet still does not work! I used my test light & connected to ground & touched a leg/connector of the missing relay & the fan came on. it is dark outside & i must get to work-nightshift!!! Does a 7 pontiac G5 vin-F with a 2.2 ECO TECH DOES IT HAVE A VOLTAGE DROPPING SOLONOID THAT CONTROLS THE LOW SPEED OR HI-SPEED FAN? IF nothing else, I did find a way to make a connection & force the fan to work but, That is not the correct way to fix it! Any & all assistance is greatly appreciated! on the interstate, the G5 runs between 183 degrees & 190 but when i sit in traffic, it gets up to 213 & i have never heard the fans run-these temps are according to the temp sensor digital read out on the dash. Thank you!
Hello, Sir. If the sig/ ref were shorted to positive, you would not see any temperature change as the TPS sensor that was shorted to voltage, right?
If the 5v ref was shorted to the signal wire, you'd have a constant 5v on that sensor signal and it wouldn't change no matter what you do
What's the brand of your flashlight
Any idea 2016 Honda crv dash light, this code coming up. I just replaced the sensor, light didn't go away.
Test the circuit with a voltmeter and report your findings. Otherwise we're just guessing.
that thing have oil in it?
When you were grounding the signal wire directly to battery negative, why does this not damage the transistor inside the ECU? I know you have previously discussed using your test light in between to protect the circuit but in this case weren't you directly grounding the wire from the ECU? Just trying to see if i missed anything, thanks
20:36
In hindsight after thinking about it, Im assuming the resistor inside the ECU would protect the transistor. Is that correct?
there is no transistor on input circuits, just a voltage sensing circuit. And yes, there is an internal resistor and this circuit is designed to be shorted to ground. Essentially the thermistor itself causes a slow bleed off to ground as it heats up
@@ScannerDanner makes more sense, thank you!
May I ask sir I have the some code as your p0118 ,I checked the signal from the ECM it's 5v and my ground is ,it's a two wiri sensor , so my question is after changing the sensor I have to learn it
No sir, not on a temperature sensor.
I have a problem with a Mercedes, the fans wont kick in even when its hot, I checked the 5v reference and it shows 3.4 volts, would that be my problem? It should be 5v right??
Some of the EURO cars had a 3v ref from what I've heard. Not sure.
so if i have got it right.the increase in idle speed was that the engine was running weak or rich due to the ECU thinking that the temperature was lower than it actually was?
Dee Hounslow for sure a lower than normal ECT reading will make it run rich but this doesn't in itself increase the idle speed. It is the computer program that will provide a "cold fast idle" based on ECT temp. and it does this by opening up the IAC valve.
so, this three wire sensor, one wire is ECT signal, 2nd wire is gage, and what is the 3rd wire? Thank you so much Paul.
A shared ground
Question... I am sure you are very busy but I have a gauge that goes straight to Hot when in the on position, even though the vehicle has not ran. However, the fans turn on when the vehicle hits or goes over operating temperature. They're only two wires coming from my heat sensor, I put a voltmeter to the wires and they came out good. This is a 04 Dodge Stratus Coupe with the Mitsubishi engine 2.4 l. Any idea why that gauge stays on hot? Thank you...
I believe the gauge is a separate sending unit on that model? If your cooling fans work as designed then your coolant temp sensor is fine. If it only has this one sensor, then you have a cluster issue. If it uses a separate gauge sending unit, I would start with voltage tests on that sensor first.
Scannerdanner 2006 Nissan altima 2.5 I have a problem with the temperature sensor... When my car is in Parking idle, reverse or neutral the temp gauge is at the Normal position but when I shift to drive the temp gauge starts moving and bouncing to high temp but when I shift to park reverse or neutral the temp gauge change quickly to normal position ... I took to the mechanic shop they replace temp sensor, fuse box even the cluster but I still have the problem ... Can you let me know what do you think about it ? Thanks !!!
+jhep1985 not through text on a screen my friend. I would need to see the car. Are you close to my school in Pittsburgh PA? I would look at it for you there for free
can this shut my car off ? my idle goes down and shut my car off , I replaced my Coolant Temperature and for 2 weeks it was all good , then I drove a little faster and the raps went up and almost stuck with on high raps !! , can you give me a tip ?
Was it not a risk to the 5v pulling it straight to gnd? Safer doing it through a test light? Cheers.
No risk at all on thermistor circuits as the 5v ref IS the signal wire and is designed to be pulled to ground. I'm fact these ECT circuits are built exactly like a pull-down type switch input.
wish to work with you man!
if the sensor isnt working will the vehicle not want to start
👍
INTELLECTUAL Sir ScannerDanner
My Mentor Sir ScannerDanner
From Nick Ayivor from London England UK 🇬🇧 ⏰️ 16:59 Good Afternoon
mr. danner i need a snap on scan tool with scope and i found used ones on ebay modis , solus , vintage .
which one is the best for home mechanic and small workshop ?
thanks for the great videos .
toolman talal you need both a scope and a scan tool. The Modis is the Solus and Vantage combined. So it is your choice. Either get the Modis or get the combo Solus and Vantage
Thanks
ScannerDanner $$$$ ouch!! Is there any other sollution? How about a cheap scan tool with using a fluke 123 scope meter? I know vehicle limitation would be a factor.
Tony Home In this case yes, any OBD II generic scan tool could have been used along with a simple multimeter.
Would you recommend buying a used Modis? Like ebay or craig? Now I know the general risks in buying used. I think what I'm asking is in your experience with being in the trade, does this tool get abused and generally get replaced frequently? I see that the tool cost around 6k new. But I've seen them for 2500 and even 1200. Is there a chance there selling them cause maybe guys hook it up wrong and damage a certain part of the meter? and again we are just chatting about this. I don't hold people to their words on these kind of matters.... :) I know in my field I've done it and seen many tech hook up their meter to read amps(ma) and not put the wire back for volts then test voltage and blow the fuse. Then since they don't have a fuse they take the foil wrapping off of comm. wire then wrap the fuse only to do it again and this time blow the meter....... Sorry for the long message.
Do I have to learn the temperature sensor after changing it , cause I have the same fault as this one higher V
not for an engine coolant temperature sensor
@@ScannerDanner the fault code say that too voltage
Could we check the wiring integrity by watching the scan tool and trying to pull that 5v reference down with a test light?
Nevermind you just answered my question
Nevermind you just answered my question
So that integrity of the ckt has to be checked for with voltage rather than temperature with the scan tool. Unless it bottoms out when you unplug the sensor. Is close to right?
Just remember that the scan tool can and will substitute values and if you use global obd2 mode, they are not allowed to show substituted values in that mode
Will a ect sensor that is reading all over the place, cause Cooling fans not to turn on? My temperature gauge works, but the reading on the sensor while reading live data, goes up to about 90 celcuis and drops to about 5 celcius, it's all over up and down.....and sometimes it it idles high at times.
If it reads colder then normal, yes. If you disconnect it, the default should be to run the fans continuously
@@ScannerDanner awesome thnx...!! If i understood correctly....you mean if I disconnect the ect the fans should turn on by default?🤔
@@crystrezerex2life yes sir! As long as it's not an older car that may contain a separate cooling fan switch
@@ScannerDanner thnx again, I really appreciate it.
Is the 1999 Ford f350 V10 supposed to have 11 volts at coolant sensor thanks
How many wires go to it? Typically I'd say no, but there are variables on systems where it could be some type of fan switch or could be a sending unit for a gauge depending on the year
@ScannerDanner it's a 2 wire everybody says it should have 11 volts going to it because it's a gauge driver
hi! I'm having a code on my o6 passat 2.0t. p0118. The car starts rough. my fan turns on as soon as I start the engine. I measured the Voltage on the harness and it shows 14v instead of 5v. Tested continuity on ground and it fluctuates. I'm using a multi tester. Do you think it's the pcm?
What is the definition of the P0118 code?
engine coolant temperature circuit high input sensor 1.
this car has to sensors one on the cylinder head and one at the thermostat housing both read the same volts. these sensors only have 2 wires. thanks
engine coolant temperature circuit high input sensor 1.
this car has to sensors one on the cylinder head and one at the thermostat housing both read the same volts. these sensors only have 2 wires. thanks
engine coolant temperature circuit high input sensor 1.
this car has to sensors one on the cylinder head and one at the thermostat housing both read the same volts. these sensors only have 2 wires. thanks
hey paul i got a problem with my jeep cherokee 1992 its giving me a code 63 Controller failure. EEPROM write denied . What can i do to repair it??
jo mang Not much you can do on a 92 Jeep other than replacing the computer.
ScannerDanner Premium thanks a lot paul .
I bet the lines on the Cobalt were bad right around the drivers side rear wheel well, under the shiny wrapping.
Good afternoon. How much is your book. engine diagnosis. Thanks in advance
I have an eBook that is $49.95 and a paper book that is $99 www.scannerdanner.com/buy-the-book.html Thank you!
Very nice but I'm lost.. what is the fix? wiring or the ECT failed?
Thanks
axenz axtiz The ECT sensor was bad. The main portion of this video was to show how to verify wiring integrity for any thermistor circuit.
ScannerDanner Hi, thanks :)
Dan
Found out somebody Torqued my front wheels into the hubs with a impact gun
Replaced several studs and
Lugs
Car has zero rust underneath
But Rotors full of the worlds rust
Driving home from buddies
Car ran so much better and was so much more stable then started running like rich and lean in and out of gear
Like the Trans speed sensor is bad
Gonna clean the wherl speed sensors
New rotors today (platinum)
And see if ESC and ASB
Are affecting Computer
Do you have anything on this kinda stuff in vids ?
Everytime my car is Crazy
I know they have driven you crazy so i have a laugh 😆
hey scanner Danner...had a question...i am checking a 5volt ref for a map sensor on a 2001 chrctysler town and country v6 3.8L ...i disconnected the map connector and have both pcm connectors disconnected ..im showing 4.8volts on my meter..is that possible
+Roberto Z nope. You sure that's not 4.8mv?
It was odd to me
...now since u respondind back to me i recheck now i have 0v
I was checking my powers and grounds..becuz the pcm does not comm with modis
I have comm with tcm ..bcm..and abs..just not with pcm and car was running crapy found a broken correded map sensor replaced it and when i went to check signal integrity and 5 v and sengrd i pull back in tubing ..all 3 were correded mesh toget...so i repaired...and was checking that and thats when i hit u up
By the way it vehicle does start and crank over
YOYO SCANNER DANNER IS THE 🚹, 👍 👍.. Temp sensor should it be replaced with oem or aftermarket ok?
I'm okay with aftermarket for a temp sensor
How come you didn't use the component tests that are included in the Verus??
Wayne Arents didn't need to, these thermistors are all tested the same way.
ScannerDanner But it would have told you the 3rd wire was for the gauge. ;)
Hey Paul,have you heard of periscope? It would be awesome to see you do this live. it's a new app that came out, it's basically RUclips live.
joeandgod1 it's an app for a phone? that wouldn't make for good camera work
Look into it, I'm pretty sure it's gonna be the next big thing, after RUclips.
with witch scan tool scanned ?
Snap-On Verus
I have a 1999 Ford f350 V10 with a po118 code it has 11 volts on wire that should have 5 volts I Ford where they split and go into computer and cluster so I cut them there and was going to bypass the short so I cut it off at computer and traced it going to cluster so now it blows all 3 computers it don't make sense because there's no other circuits on that wire any ideas
You have 11v on a 5v supplied circuit? You have a bad computer ground!
@@ScannerDanner the ground is good I think there's a 12 volt wire rubbing on the 5 volt wire
@@ScannerDanner and the ground is in the kick panel
@@ScannerDanner where would the pcm ground be on a 1999 Ford f350 V10
@@ScannerDanner can you help me no shop even Ford can't figure this one out
Knock knock!
What was the cause of the fuel smell issue on the yellow submarine? I've heard that a faulty ECT or thermostat could cause a rich condition.
My coolant and engine dash indicators are on. My Saturn runs like a top. Can't figure it out, BUT I'm no mechanic.
I explained this situation to my mechanic and he said "f*** it Its likely a computer issue". I don't know where the ECT sensor is anyway to replace it though I bought a new one.
David
Alberta
an ECT sensor fault is certainly common on Saturn systems but if you have a low coolant light on, on the dash, there is a low coolant switch in the plastic overflow bottle of the cooling system that will often stick. Smack on that coolant bottle a few times after verifying your coolant level is correct of course.
What is "my coolant and engine dash indicators", do you mean "low coolant" and "check engine light"?
In My Car From the last month I am facing weired issues:
- Fuel Tank Got Shrinked Which caused wrong fuel indication.
After installing a new Tank i am seeing whenever I open my fuel tank cap, air vacuum releases.
- Another problem is. My temperature gauge is going 1/4 only.
2 months ago I serviced this car.
Oil change, Oil Filter change, Air filter change, Installed thermostat which was not installed before,
After servicing I ran 150kms. Everything ran fine,
But now I am facing these two issue.
Steps I have taken
: Checked temperature guage by grounding it. It works fine.
So I installed new temperature sensor.
But same thing happening.
I HAVE CODE PO430 ON MY LINCOLN 200 LS HOW CAN I FIX THIS
+Allen Mcdaniel change the cat.
As long as there are no exhaust leaks or any other codes (fix those first)
Good morning to everybody I just need some help hope fully someone can help me I got a 97 cadillac deville with overheating problems but I will wxplain you guys what I did and what Im doing with, normally the temperature has to be on 222 f and the fans fire on and the temperature goes down to 210 f to 215 f so for me thats good but sometimes after the fans kick on the temperature still raising on I tried the heater turning on and sometime works and sometime doesnt so I already change the thermostat , temperature coolant sensor has new coolant I never leave the car runs after 230 f to 236 f so I shut the car off before to get there hope fully you guys can help me with some ideas or solutions ( Paul Danner I love you videos and how you explain everything you have to do just what a can tell is thank you and keep going)
You most likely have a head gasket failure :-(
Use a block tester (chemical test kit) ruclips.net/video/k5VVcNKAK6U/видео.html
What if the temperature indicates a normal temperature while driving (around 160°F) and then suddenly drops to -40° (for a long minutes)?
It is becoming more and more difficult to answer questions here. I have 80,000 people asking me for help now. So I have created a forum to help you guys better. It is free to join and we can exchange pictures, wiring diagrams and waveforms if needed to help guide you through the process of troubleshooting your vehicle. Thank you so much! Hope to see you there.
Paul Danner (ScannerDanner)
www.scannerdanner.com/forum/post-your-repair-questions-here.html
loose connection or a break in the wire. When you unplug a thermistor sensor most cars default to -40
Dude, the "scannerdanner.com" is in the way of the RPM readout!!
+Chris G sorry man, it's too late to fix it
I know......just giving ya a heads up for next time, dude! I love your vids and your knowledge is phenomenal! Trying to save up to buy your e-book.....you got to do some 1999-2001 Saab 9-5 and 1998-2002 Ford Crown Vic stuff, brah!!
KNOCK KNOCK WHO'S THERE ECT
I have a similar issue. 97 Cadillac Deville Northstar after a theft issue my car started having idle issues. From my buddys expensive scanner it shows its not in open loop even at 215 degrees. normal operating temp is 225 at the tops. Idle Air Control valve is good, all my input sensors are good. no codes. leaning towards coolant temp sensor. although it reads good on scanner. engine does feel hotter than what my temp says.
Not in open loop at 215? It should be in closed loop, so that is okay. Open loop is a mode the computer enters until the oxygen sensors warm up and are functional. If your engine is hot and you are still in open loop, this would be from some type of fault. Certain O2 related fault codes, severe misfiring, overheating conditions would maybe force a hot engine open loop.
"Feels hotter" is not good enough my friend. We need an actual engine temp measurement compared to the scan data ECT.
Idling issue? As in rough idle, stall? Or shaking idle like a misfire?
@@ScannerDanner maybe I misunderstood the open and closed loops. Got an interesting electrical situation. Tried digging and diaging everything I could research and think of. High idle condition with no vacuum leaks, no codes. Possibly low fuel pressure or maybe my pressure gauge was off if I didn’t bleed the air out. Current idle is 1800rpm, and it doesn’t return to normal(cables aren’t hanging up, throttle isn’t sticking open either) almost seems like the IAC is opening to lean out a rich condition if that’s how it might work. Or not. I’m a rookie and my diag “skills” are still in need of TLC 😂
@@MechanicalMikesRoadsideRepair all good my friend.
Okay, you have an 1800 rpm idle.
1. What is your IAC counts or steps during this condition?
2. What is your TPS closed throttle voltage during this condition?
3. If available, what is your TPS closed throttle %?
4. When did this problem start?
@@ScannerDanner Was about 120 something 130 something counts out of I believe the max 150. Unable to command the idle with the scanner saying “unable to control idle, throttle not at idle” type message. Throttle voltage not sure but the position at idle was no higher than 2.0%. This problem happened after my theft system triggered randomly. Stopped for food, my car wouldn’t start after I shut it off. I know it was a bad IPC since I swapped another from another car and the key and steering column (was doing an entire interior swap anyways) didn’t have it in long enough to know if it fixed the problem. It did start as normal. But then I mixed my keys up and put the wrong one in and triggered it 😆😢 PCM is programmed to disable VATS so all I did was ground the starter enable relay so now I’m able to start up and run my car but I still have B2780 present. Haven’t been able to get it off. Might end up getting the programmer tool for it or another cluster and key whichever is cheaper. PCM was proven good when the programmer showed it in another car running perfect. And I don’t believe I installed it incorrectly. Really really odd situation. My car did sit at a shop for 5 months because the shop didn’t really know what to do with it to get it started (I towed it to my tech school with help from my teacher we got it running by grounding the relay and I installed the programmed PCM) thanks for reading my comments and responding. I do have alldata for my car too, as well as factory service books.
@@MechanicalMikesRoadsideRepair okay sweet! Normal, hot engine, no accessory loads, at idle should be around 30 counts. The 120-130 you are seeing means this is a command for the IAC to open and it is just doing it's job (3000 RPM idle speed lol). This is not an IAC problem. You absolutely have an input problem and are wise to be focusing on the ECT as it is one of the inputs used. But the minor discrepancies you mentioned earlier are a non issue. The ECT is not your problem. Now the TPS, let's focus there for a minute. I believe on your model it should be 0% at idle. If it is supposed to be 0, a 2% throttle opening WILL ABSOLUTELY cause what we have. The ECM thinks your foot is on the gas pedal and it is preparing the IAC for when you let off (prevents decel stalling). Make sense?
Now some cars, it is normal to see as high at 10% at idle, but I do not think on your model. It has a throttle cable right? It isn't an electronic throttle body is it?
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Amateurs. That temp sensor is essentially an RTD and the extra wiring is for calculating the resistance in the wires not for the gauge :). The gauge is controlled by the temp transmitter in the ecu.
spasev You may want to do your homework before calling someone an amateur. The third wire is for the gauge. It is NOT part of the engine coolant temperature sensor circuit. If I could post the diagram here I would.
There are systems that one use one sensor and the data is shared across a network but it is still only a 2 -wire thermistor that would signal the ECM, then the ECM shares the data with the instrument cluster.
+ScannerDanner
Maybe you are the one that needs to do little research before posting a replay. RTD is a resistance thermometer, and the thermistor is a type of RTD (very inaccurate one by the way) and most likely not used on that vehicle. The type of RTD used in that vehicle is probably PT100 as it is cheap to manufacture and far more supperiour to the thermistor. 2 wire RTD's are rarely used because they do not compensate for the resistance in the wires therefore it is probably 3 or 4 wire type that properly measures the voltage drop while supplying very low current trough the probe. Also, there is no "signal" to read, but a current sensing shunt most likely 0-20ma or 4-20ma measuring the voltage drop across that shunt.
spasev I'm sorry my friend, but you are off on this one. You seem like an intelligent person, and I'm sure your description of an RTD is correct, problem is, we don't use these on automotive temp sensor circuits.
This is a simple two wire thermistor, and the third wire is for the gauge sending unit. The housing is the ground for the gauge part of the circuit, it is not a shared ground as I described in the video.
Automotive temp. sensors are not what you are describing. They are voltage sensing NOT current sensing circuits.
+ScannerDanner
Trust me my friend I know what I am talking about very well. That is the fundamental principle of how all RTD's work. If you open that ECU and you trace that input there will be a shunt current sensing resistor that looks for the current change caused by the fluctuations of resistance in the t RTD. It is basic Ohms law my friend, you should know that if you like to portray yourself as car tech.
If your going to continue with your condescending comments, I'm just going to ignore you. If you want to have a good dialog, we can do that. So which one will it be? Balls in your court.
Dude how do you keep working when your critical battery warning pops up in Windows? If I ever see that I freak the hell out and start running around looking for a power socket!
Ed Luck As long as I keep it plugged into the DLC, it takes power from the car and you can ignore that warning. The second you unplug from the car however, it will shut down.
ScannerDanner Ah, makes sense. I do similar stuff with EvoScan on my Mitsubishi but still need power from a power adapter. While on very low battery and capturing some log data one day I was reminded that the accessory circuit is cut during cranking. Yeah that was embarrassing.