No Crank - Check TPM System?

t0rquey · **Posted:** Tue Jun 28, 2016 12:53 am

Hi all. My family and I were driving my wife's CRD tonight when it just quit out of the blue. It had just shifted to fifth locked and I was rolling on the throttle to merge onto a freeway when it just shut down. The gas light and TPMS light came on as I coasted to a stop on the shoulder. I did some quick checks and turned of the HVAC before trying to start it back up. When I turned the key to run, the glow plug light came on like normal, turned off for a second, and came back on with a chime and an EVIC message to "Check TPM System". When I turned it to start, nothing happened.

I let it sit for an hour or so and went back. I pulled the battery cables and touched them together to reset everything, but the response was exactly the same when I tried to start it again. We checked some fuses and relays, but everything looked normal. I am suspecting it to be a BCM issue. What say you guys?

jws84_02 · **Posted:** Tue Jun 28, 2016 7:17 am

Has the jeep been in the rust belt it's whole life? I had one from Michigan and the bcm was so rusty chunks feel off when I went to take it off. My guess is that or a wiring issue somewhere :banghead:

t0rquey · **Posted:** Tue Jun 28, 2016 7:25 am

I don't know the location of its first 88,000 miles of life, but I did buy it from a dealer local to me, so I always assumed it is a native Indiana Jeep.

I am torn between having it towed back to my house versus having it towed to a dealer. I figure that, if the BCM needs to be replaced, the dealer would have to flash it. Does this sound correct?

Sir Sam · **Posted:** Tue Jun 28, 2016 10:31 am

Sounds like we might be having the same issue though who knows if its the same cause.

I do not think it is the BCM as I am able to communicate with the BCM. I plugged my DRBIII in and the BCM showed communication, and was able to IO display of things like the foglight switch etc.

Does your keyless entry still work? Can you turn the headlights on and then the foglights? if that is working then the BCM is still doing its job.

t0rquey · **Posted:** Tue Jun 28, 2016 11:00 am

Yes, the RKE seems to function well and all the lights work. I guess I assumed that the TPMS was controlled by the BCM. Perhaps it is the FCM at fault?

I wish I had a DRBIII right this minute

Sir Sam · **Posted:** Tue Jun 28, 2016 12:14 pm

I think thats a good indication its not the BCM but rather something in the engine harness or power to it.

If you don't have the manual download it and use it to reference the pinout for the ECU and the TCM. Start checking pins and see whats right or wrong.

Sir Sam · **Posted:** Tue Jun 28, 2016 10:51 pm

I found fuse 14 blown in my drivers side kick panel. Replaced it and jeep runs.

t0rquey · **Posted:** Fri Jul 01, 2016 10:25 pm

I talked to the dealership this evening. The service manager said that it needs a PCM. The quote was $675 for the PCM and three hours labor, so about $1,100 after tax. After reading about Sir Sam's findings, I am seriously tempted to just have it towed home. I struggle to believe that the PCM just randomly took a dump...

WWDiesel · **Posted:** Fri Jul 01, 2016 10:46 pm

I would tread very carefully!!!
Unfortunately most dealer mechanics do not have a clue about these vehicles! We read horror stories on this forum quite often of dealerships making wrong diagnosis and / or shoddy repairs... :roll:

LOST and its members are your best friend on this vehicle....

Billwill · **Posted:** Sat Jul 02, 2016 4:18 am

Definitely ignore what the Dealer said....they will replace every part in your Jeep until it runs...or does not run as they would have omitted some programming somewhere or would have created a few extra problems in the process!

Download the KJ Service Manual for your year KJ here...includes theory of operations, fault finding and wiring diagrams:

http://www.colorado4wheel.com/manuals/Jeep/KJ

Check all the fuses, under the hood and inside the cabin and check the harness that Sir Sam mentioned in his fault finding and then report back here...the team of experts on this site have more chance of finding your fault than most "CRD" trained Dealers! :wink:

At the moment does the Jeep not crank at all?
Any other error codes stored?

Swap over the ASD Relay under the hood with an identical one next to it and do the same with the Starter Relay.

t0rquey · **Posted:** Mon Jul 04, 2016 1:47 pm

When it was stuck on the side of the road, I checked all of the fuses under the hood, but I didn't know where the interior fuse panel was located. I swapped the ASD relay, as well as the starter relay, but had no change. I wish now that I would have dove deeper into the service manual to learn about the interior fuse panel, because I highly doubt the dealer has even looked there. My suspicions about the ecu not getting power were confirmed by the dealer, but I am very inclined to think that the pcm is fine. If the dealer did find a bad wire, I'd imagine that they would want to replace the entire harness. I'm going to have it towed home tomorrow...

WWDiesel · **Posted:** Mon Jul 04, 2016 2:46 pm

Is yours an 05 or 06? If you do not already have them, get yourself a good 12v test light and a multi-meter and then download the service manual from link Billwill provided which contains the wiring diagrams for your vehicle. Check all fuses that can fed the PCM with test light and make sure they are have 12v on both sides of the fuse. Just looking at a fuse you cannot always tell if it is blown or not. Test light or voltage meter tells all! If all fuses are good, then I would check all grounds and make sure they are good and tight with no corrosion. A bad ground can cause all kind of crazy problems!!!
If all grounds are good, then it is time to start checking the wiring and try and backtrack from the PCM back to the 12v battery source.
Good luck and keep us posted and hopefully there are individuals on this forum that can help you find the problem.... :wink:

If you have problems reading the wiring diagrams, just ask for help, they can be kinda hard to follow and several on here are very good at reading them....
Hopefully it is just a bad fuse or wire and not the PCM :roll:

t0rquey · **Posted:** Tue Jul 05, 2016 11:27 pm

So I got the KJ back home today. Within twenty minutes, I had found a worn spot in my harness, located fuse #14, and saw that it was blown. I swapped it for another 10a, and lo and behold, the Jeep fired right up. Looks like I'll be making a trip up to the dealer tomorrow morning. Many thanks to Sir Sam for the legwork on this one!

Sir Sam · **Posted:** Wed Jul 06, 2016 12:50 am

t0rquey wrote:

So I got the KJ back home today. Within twenty minutes, I had found a worn spot in my harness, located fuse #14, and saw that it was blown. I swapped it for another 10a, and lo and behold, the Jeep fired right up. Looks like I'll be making a trip up to the dealer tomorrow morning. Many thanks to Sir Sam for the legwork on this one!

No problem, when can I expect that cooler of beer? :5SHOTS:

WWDiesel · **Posted:** Wed Jul 06, 2016 10:00 am

t0rquey wrote:

So I got the KJ back home today. Within twenty minutes, I had found a worn spot in my harness, located fuse #14, and saw that it was blown. I swapped it for another 10a, and lo and behold, the Jeep fired right up. Looks like I'll be making a trip up to the dealer tomorrow morning. Many thanks to Sir Sam for the legwork on this one!

Glad you found the problem!!! Sam's original problem and diagnosis/fix provided a big clue and may help others in the future with a similar problem. :rockon:

After Sam's find, I went and checked all the wiring harnesses on top of my CRD motor for any chafing or unprotected wiring and luckily found none. All wiring is still in OEM harness protectors but I think I will add some new ones in critical places just to be pro-active. Plastic wiring loom covers are CHEAP! The old plastic protectors are very brittle and will break or crack if you move them any... :roll:

t0rquey · **Posted:** Thu Jul 07, 2016 7:40 pm

I went and talked to the service manager at the dealer today, and they are going to credit me for what I paid on the misdiagnosis. I told him that I had it running in twenty minutes and showed him the blown fuse. I was pretty impressed because he actually offered the credit. I don't think I'd ever take it back there, but I suppose I hold a neutral feeling about the whole endeavor.

Sir Sam · **Posted:** Fri Jul 08, 2016 12:36 am

Thats about as good as you could get under the circumstances I suppose, maybe a free oil change credit or something.

Can you share a photo of where you found the wire issue on your harness?

No Crank - Check TPM System?

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