Great job Jake! It's so easy to just throw the parts cannon at it, but constantly questioning our methods is the best way to come up with a solution. I've seen this wiring issue before on the Commodores we have here in Australia. I did one recently where the oil travelled up from the oil sender as well as the VVT sensors and actuators and created a huge puddle of oil in the ECU connectors. It took out an injector driver and I had to replace the ECU. Keep the videos coming! 😉👍
Nice of the manufacturers to make wiring insulation out of oil soluble garbage that rats love to chew on. I run into this on a regular basis. Good job sir.
I wonder what the extrra cost would be to use polypropelyne tubing instead of all that tape and split loom tubing to run wiring through--especially in hard to get to places like this. We used stuff called 'polytuff' to run small wiring on heavy machines. Use marine grade heat shrink at the base of the electrical plugs and the end of the tubing to make a complete seal. Polytuff is even flame resistant. Would save a Iot of headaches down the road. I know--headaches are not the concern of the OEMs.
I feel your pain on the Dodge/Jeep schematics. I was chasing a shorted 12v pcm output (blowing a pcm fuse), on an '11 Grand Caravan last week. I knew it was a 12v output, but which one? They sure don't do a very good job of labling their outputs. Mine wound up being a shorted oil pressure contol solenoid. Enjoyed the video Jake, keep 'em coming.
Nice diag Jake! You know I never thought of testing each sensor resistance to ground through the module connector, but if it lives in a hard to get to place it is a great process. Definitely a valid test as you have just proved! Makes you feel much better when removing that intake manifold. Excellent video and thank you for this one!
I have been watching people test the 5 volt Ref for years and only ever seen them keep the circuits connected and go around disconnecting one at a time till the 5 volts came back and called it a bad sensor and if it never came back then they risk replacing the Ecm. This video has just shed light on me and given me a new way to be sure if a sensor or circuit is shorted before calling a Ecm. Great video Thanks heaps. PS: I guess I have been lucky as so far unplugging sensors has got me through and I have never had to call an Ecm. But....... Now i can be certain if it gets to that point. The other thing that comes to mind is that your not disturbing the wires by unplugging sensors which obviously could lead you astray if the wires are disturbed Loved it.
Someone in part one mentioned something about the oil sensor, sometimes running onto a problem before it tab's help but either way I never thought of checking for pcm shorted to it's own casing, although I'm not a mechanic I enjoy watching your vids that keep this old man occupied. Thanks for sharing
Imagine being a fiat dodge/chrysler technician at the dealer and having to build these 5v circuits in your head all the time - and its under warranty so you get paid minimum wage or nothing to do it. Glad I got out of the dealer scene in 2023. Wish I'd done that 8 years ago. We enjoy your content man! My new job is purely doing diags just like yours (the "hard" ones other guys didnt do or couldnt do) so im gonna start watching a lot more!
Well done Jake!! I know that a lot of 3.6L Pentastar engines are having the oil cooler leak issues that have to be fixed! One shop I visited said they do 4 or 5 a week continuously! It would be interesting to check with some shops in my area to see if that wiring harness needed to be replaced during the cooler repair process. I think the wiring harness issue would get more severe depending on how long the oil spill at the cooler is be allowed to contaminate the wiring.
Nice video and diagnosis. I had my money on a shorted out sensor and would have started unplugging them one at the time. Seeing that harness brought back memories of working on my 90’s Mercedes cars that had wiring issues.
Great diagnostic and repair! My initial call was a problem inside the PCM plug, but this could extend to the full length of the wiring (I should have re-watched the previous video, to see why I mentally excluded the wiring, but I was a bit lazy). Thanks for another excellent video, Jake!
Had a Chrysler (Jeep) ECT sensor that was bad inside of the connector itself. I had to borrow a ground off the MAP sensor. Had resistance about 1/2 inch up from the ECT connector but not by touching the pin (front or back). We used a Mopar pigtail.
Same goes for misfire monitors. Not all manufacturers give you live data for misfires and to me this is irritating. We all have methods for figuring it out regardless. But it's obvious the pcm knows which cylinder is misfiring because it will eventually throw a code for it. But even that sometimes is irritating because you'll get a P0300 for a single cylinder misfire. Any case just let us see which one is misfiring so we can get to why sooner. Instead of going through whatever it takes to get to the point where we know exactly which cylinder is misfiring.
Awhile back had a GM truck which was clearly misfiring yet the misfire counters would not show it. Would not even set a current P0300. I thought i was imagining it and said to my foreman to put his hand on top of engine. Yup its a dead miss. I know but look at the data. Turns out if fuel level is too low it would not set a current code or count misfires. Added fuel to it for a road test and counters started to count misfires. Just some info in case you run into this. Had me confused for a little bit.
Nice repair and find Jake . Maybe when we saw 100 psi on the dash readouts it should have rung my bell . Really have not seen any cars with 100 psi oil pressure . Thanks for the updates Artie 👍
@@grad0n that’s a cold start and it’s in high pressure mode. It also started out saying 0 psi where before it said 100 with the engine off. So not really sure what you are saying is wrong?
oh yes i feel that pain . our older drawings you could click on the splice and it would list out what ever else was on there also click on the connector and it would take you to the location . new ones oh no none of that and to top it off new ones give you a description of the block as in body to body or body to facia but no terminal block number . oh no for that you have to use another drawing . man i tell you that boils my p*** . great example there my friend of thinking outside the box or you could be eating a £1000 ecm 😱😱😱
Your scan tool's pre-repair analysis showed an issue with the oil pressure sensor in your first video. It's definitely challenging to determine right away if that is related to the TB problem or a different one altogether, especially without the thorough tests you conducted. Did you think it was unrelated at the first glance of the code scan?
At first I was unsure because I knew the had replaced the sensor, along with the crank sensor and both cam sensors. So since it said history instead of current I honestly didn’t know.
No but I would highly suggest it to newer techs until they fully learn and understand the circuits they are testing and how stray voltage can give false reading.
I was just told in order to fix a p0303 that I needed to replace the PCM on my '12 WK2 5.7 Jeep GC. Recently, I had the radiator, battery, starter and all 16 spark plugs replaced. The shop did a #3 cylinder compression test, and moved the ignition coil, but the p0303 code's still there. My fuel mileage has gotten really bad too. There's also an oil leak from the oil pan gasket, and oil seeping from the valve cover. Before I pay for a new PCM I need to see if there's another issue. A p0303 means the problem is exclusive to the #3 cylinder, right?
I wouldn’t trust a compression test on that engine. A failed exhaust lifter could still give good static compression readings. A relative compression test would be much better.
Not sure at what point in the video you made this comment but no it didn’t have anything to do with the mechanic that put the oil cooler in. This car was actually having this problem intermittently before the oil cooler was replaced.
I think it just comes up as Harness in the parts catalog. There is 2 different versions of it for different oil pressure sensors but that’s determined by the vin. I just tell them I need the harness to the oil pressure sensor and knock sensors.
The short “appears” to go away when the pcm is unplugged. What most techs and even service info miss alot of times is the short to ground doesn’t have to be to the engine block or something else. The short could be to a low reference ground wire that has to travel through the pcm before actually connecting to chassis ground.
"These harnesses are not that expensive." $150 bucks!!! WHAT?! If that wire insulation is breaking down from oil saturation then it should not cost anywhere near $150. It means they are charging you for the more expensive automotive or marine grade wire but giving you the cheap plastic insulation wires.
That diagram wont even show all the shared circuits. that 5volt shares with all kinds of shit. The oil pressure sensor that is aftermarket is a common 5volt short on Mopars.
Nice diag and repair, Jake! I like the non intrusive testing from the PCM connector 😁👌
I really like your thought process. What would we do if the new module did not fix the issue. Yup! thinking out of the box. Excellent.
Great job Jake! It's so easy to just throw the parts cannon at it, but constantly questioning our methods is the best way to come up with a solution.
I've seen this wiring issue before on the Commodores we have here in Australia. I did one recently where the oil travelled up from the oil sender as well as the VVT sensors and actuators and created a huge puddle of oil in the ECU connectors. It took out an injector driver and I had to replace the ECU.
Keep the videos coming! 😉👍
I would give 5 thumbs up for this diagnoses if I could.
👍👍👍👍👍 here ya go, best I could do.
You have a correct and reliable diagnostic process. I learn from you all the time. Thank you for sharing. You are a champion.💙
Nice of the manufacturers to make wiring insulation out of oil soluble garbage that rats love to chew on. I run into this on a regular basis. Good job sir.
Great diag Jake! Very methodical! Great conclusion 👌 Jake, Ivan and Eric. You guys Rock!
I wonder what the extrra cost would be to use polypropelyne tubing instead of all that tape and split loom tubing to run wiring through--especially in hard to get to places like this. We used stuff called 'polytuff' to run small wiring on heavy machines. Use marine grade heat shrink at the base of the electrical plugs and the end of the tubing to make a complete seal. Polytuff is even flame resistant. Would save a Iot of headaches down the road. I know--headaches are not the concern of the OEMs.
I feel your pain on the Dodge/Jeep schematics. I was chasing a shorted 12v pcm output (blowing a pcm fuse), on an '11 Grand Caravan last week. I knew it was a 12v output, but which one? They sure don't do a very good job of labling their outputs. Mine wound up being a shorted oil pressure contol solenoid.
Enjoyed the video Jake, keep 'em coming.
Nice diag Jake! You know I never thought of testing each sensor resistance to ground through the module connector, but if it lives in a hard to get to place it is a great process. Definitely a valid test as you have just proved! Makes you feel much better when removing that intake manifold.
Excellent video and thank you for this one!
I have been watching people test the 5 volt Ref for years and only ever seen them keep the circuits connected and go around disconnecting one at a time till the 5 volts came back and called it a bad sensor and if it never came back then they risk replacing the Ecm. This video has just shed light on me and given me a new way to be sure if a sensor or circuit is shorted before calling a Ecm.
Great video
Thanks heaps.
PS: I guess I have been lucky as so far unplugging sensors has got me through and I have never had to call an Ecm. But....... Now i can be certain if it gets to that point.
The other thing that comes to mind is that your not disturbing the wires by unplugging sensors which obviously could lead you astray if the wires are disturbed
Loved it.
Really great place to bury that harness with the heat and a badly located oil pressure sensor.
Thanks for the video Jake.
Another great diag
Someone in part one mentioned something about the oil sensor, sometimes running onto a problem before it tab's help but either way I never thought of checking for pcm shorted to it's own casing, although I'm not a mechanic I enjoy watching your vids that keep this old man occupied. Thanks for sharing
Yes someone mentioned this except issue!
Imagine being a fiat dodge/chrysler technician at the dealer and having to build these 5v circuits in your head all the time - and its under warranty so you get paid minimum wage or nothing to do it.
Glad I got out of the dealer scene in 2023. Wish I'd done that 8 years ago. We enjoy your content man! My new job is purely doing diags just like yours (the "hard" ones other guys didnt do or couldnt do) so im gonna start watching a lot more!
Nice job Jake, Got the same thing going on with the APP 2 Vref coming and going on the same YMM right now. Pretty sure something is pulling it down.
Jake, that Jeep sure sounded nice once you were done with it. Thanks for Sharing! 🙃🙂
Well done Jake!! I know that a lot of 3.6L Pentastar engines are having the oil cooler leak issues that have to be fixed! One shop I visited said they do 4 or 5 a week continuously! It would be interesting to check with some shops in my area to see if that wiring harness needed to be replaced during the cooler repair process. I think the wiring harness issue would get more severe depending on how long the oil spill at the cooler is be allowed to contaminate the wiring.
Nice video and diagnosis. I had my money on a shorted out sensor and would have started unplugging them one at the time. Seeing that harness brought back memories of working on my 90’s Mercedes cars that had wiring issues.
Great diag! Must have felt good finding those crusty bare wires instead of throwing a PCM at this thing and having the problem remain.
Fantastic video harness is definitely on the list for oil cooler replacement 👊🏻👍🏻
Great diagnostic and repair! My initial call was a problem inside the PCM plug, but this could extend to the full length of the wiring (I should have re-watched the previous video, to see why I mentally excluded the wiring, but I was a bit lazy). Thanks for another excellent video, Jake!
Interesting case, thanks for sharing
I have gotten those filter housings from Chrysler with new sensor and it be bad. I always reinstall the original sensor if it doesn't have a problem.
Had a Chrysler (Jeep) ECT sensor that was bad inside of the connector itself. I had to borrow a ground off the MAP sensor. Had resistance about 1/2 inch up from the ECT connector but not by touching the pin (front or back). We used a Mopar pigtail.
Excellent trouble shoring , thank you
Now that was really really good !!!! Great vid.
Short to reference ground, not chassis ground. And of course the short to chassis ground went away when the PCM was unplugged Tricky!
Exactly what I thought and have seen several times.
Awesome Jake you are the man!
Test test don't guess .
Wow. Great job. 👏
Same goes for misfire monitors. Not all manufacturers give you live data for misfires and to me this is irritating. We all have methods for figuring it out regardless. But it's obvious the pcm knows which cylinder is misfiring because it will eventually throw a code for it. But even that sometimes is irritating because you'll get a P0300 for a single cylinder misfire. Any case just let us see which one is misfiring so we can get to why sooner. Instead of going through whatever it takes to get to the point where we know exactly which cylinder is misfiring.
Awhile back had a GM truck which was clearly misfiring yet the misfire counters would not show it. Would not even set a current P0300. I thought i was imagining it and said to my foreman to put his hand on top of engine. Yup its a dead miss. I know but look at the data. Turns out if fuel level is too low it would not set a current code or count misfires. Added fuel to it for a road test and counters started to count misfires. Just some info in case you run into this. Had me confused for a little bit.
@jeffco908 Good info. Thanks brother.
Good job. 👍
Great fix Jake!.
Another great diagnostic. Thanks for sharing.
Thank you for the knowledge and video
good fix
Nice repair and find Jake . Maybe when we saw 100 psi on the dash readouts it should have rung my bell . Really have not seen any cars with 100 psi oil pressure . Thanks for the updates Artie 👍
That just happens to be the max the sensor can go so it's a tell tell
Wrong! You didn't see post-fix start-up hitting 99psi with partial throttle-blip?
@@grad0n that’s a cold start and it’s in high pressure mode. It also started out saying 0 psi where before it said 100 with the engine off. So not really sure what you are saying is wrong?
Great video series!
Nice!
Amazing diag.. Jake
oh yes i feel that pain . our older drawings you could click on the splice and it would list out what ever else was on there also click on the connector and it would take you to the location . new ones oh no none of that and to top it off new ones give you a description of the block as in body to body or body to facia but no terminal block number . oh no for that you have to use another drawing . man i tell you that boils my p*** . great example there my friend of thinking outside the box or you could be eating a £1000 ecm 😱😱😱
Good job!
Following you from iraq
I love your vids have a cool info
I’m glad I’m not the only person that gets frustrated by the way manufacturers makes things difficult for absolutely no reason 😅😂
Your scan tool's pre-repair analysis showed an issue with the oil pressure sensor in your first video. It's definitely challenging to determine right away if that is related to the TB problem or a different one altogether, especially without the thorough tests you conducted. Did you think it was unrelated at the first glance of the code scan?
At first I was unsure because I knew the had replaced the sensor, along with the crank sensor and both cam sensors. So since it said history instead of current I honestly didn’t know.
Good 👍
Are you doing the resitance with battery disconnect
No but I would highly suggest it to newer techs until they fully learn and understand the circuits they are testing and how stray voltage can give false reading.
We can't expect the manufacturer to build that harness with silicone wires resistant to oil. I would pay the extra for the protection.
1:55 internal short within a connection ( green booger) or sensor itself
I was just told in order to fix a p0303 that I needed to replace the PCM on my '12 WK2 5.7 Jeep GC. Recently, I had the radiator, battery, starter and all 16 spark plugs replaced. The shop did a #3 cylinder compression test, and moved the ignition coil, but the p0303 code's still there. My fuel mileage has gotten really bad too. There's also an oil leak from the oil pan gasket, and oil seeping from the valve cover. Before I pay for a new PCM I need to see if there's another issue. A p0303 means the problem is exclusive to the #3 cylinder, right?
I wouldn’t trust a compression test on that engine. A failed exhaust lifter could still give good static compression readings. A relative compression test would be much better.
I'm guessing the tech pinched a wire when changing the oil cooler.
Not sure at what point in the video you made this comment but no it didn’t have anything to do with the mechanic that put the oil cooler in. This car was actually having this problem intermittently before the oil cooler was replaced.
what do they call the harness. i am going to get one!!
I think it just comes up as Harness in the parts catalog. There is 2 different versions of it for different oil pressure sensors but that’s determined by the vin. I just tell them I need the harness to the oil pressure sensor and knock sensors.
@@autodiagyt ok thanks you may have saved me extra work that is a f-up area to have to tare apart 2x happy holidays
This is the exact type of electrical understanding that is lacking in the industry. It’s also part of the next class I’m going to write.
PJ keeps telling me I need to write a class but I don’t know where to start or what to cover lol
If it's a Jeep, it's usually a short or bad ground. lol
A Chrysler without the dreaded red locking tabs
that was a good one!
Chrysler bad 4 looped and shared grounds
👍👍👍👍 nice
❤❤❤❤❤❤❤
Jake I hope it's not silly question....why u didn't get the short while u check the short in 5v in part1.. Is not the same 5v for all sensors???
The short “appears” to go away when the pcm is unplugged. What most techs and even service info miss alot of times is the short to ground doesn’t have to be to the engine block or something else. The short could be to a low reference ground wire that has to travel through the pcm before actually connecting to chassis ground.
"These harnesses are not that expensive." $150 bucks!!! WHAT?! If that wire insulation is breaking down from oil saturation then it should not cost anywhere near $150. It means they are charging you for the more expensive automotive or marine grade wire but giving you the cheap plastic insulation wires.
PTFE insulation is what I was thinking of. Wire with PTFE insulation is what you would want in the middle of the engine like that.
Bad 3rd brake light bulb 💡
?
That diagram wont even show all the shared circuits. that 5volt shares with all kinds of shit. The oil pressure sensor that is aftermarket is a common 5volt short on Mopars.
Great video, another garbage Jeep....really good video.
Great video Jake fine diagnostic work.