My jeep died while driving down the road and will not start back up. The security key light is on and everything else on the jeep seems to be working right but when I try to get a code it will not communicate with the PCM. I have read that some sensors can go bad and cause this problem and was wondering if their might be anyone that could point me in the right direction as to which sensors to test first so I am not going through all of them for no reason. I have a 2006 Rubicon unlimited. If anyone else has any other ideas as to why this may have happened please let me know as I am not very mechanically inclined and really don't know what I am doing. Just trying to fix the problem myself if possible to save money and keep from having to take it to the dealership.
No communication with PCM
- Thread starter ADsLJ
- Start date
There are a few things that come to mind. If you’re plugging a scanner into the datalink connector and it won’t communicate with the PCM, make sure the ground from the back of the head (engine) to the firewall is good.
Another possibility is that the ignition actuator pins broke and you’re not able to turn the key far enough to wake the PCM.
Good voltage and clean grounds at the battery are vital for TJs. Make sure the battery is good and that the posts, terminals and grounds are clean.
If everything above checks out, there’s a high likelihood the PCM needs to be replaced. It sounds like the ignition sense circuit has failed.
Another possibility is that the ignition actuator pins broke and you’re not able to turn the key far enough to wake the PCM.
Good voltage and clean grounds at the battery are vital for TJs. Make sure the battery is good and that the posts, terminals and grounds are clean.
If everything above checks out, there’s a high likelihood the PCM needs to be replaced. It sounds like the ignition sense circuit has failed.
Powelligator
New Member
Holy Thread From The Dead, Batman!
If the OP is still around, was there ever a resolution to this problem? This just happens to be the EXACT SAME SYMPTOM of a problem I'm seeing with my 2006 LJ Rubicon. In my case the buzzing / clicking sound coming from the glovebox is actually coming from a couple of relays on the fuse block - directly ahead of the glovebox. Another thing that's different with mine is that sometimes the Jeep starts right up and acts like nothing is wrong, then you can shut it down and it won't restart - until it feels like it.
I'm thinking a ground problem, the Jeep just celebrated it's 20th birthday, so maybe corrosion with the grounds?
Thanks!
If the OP is still around, was there ever a resolution to this problem? This just happens to be the EXACT SAME SYMPTOM of a problem I'm seeing with my 2006 LJ Rubicon. In my case the buzzing / clicking sound coming from the glovebox is actually coming from a couple of relays on the fuse block - directly ahead of the glovebox. Another thing that's different with mine is that sometimes the Jeep starts right up and acts like nothing is wrong, then you can shut it down and it won't restart - until it feels like it.
I'm thinking a ground problem, the Jeep just celebrated it's 20th birthday, so maybe corrosion with the grounds?
Thanks!
Powelligator
New Member
I reckon then the question now morphs into...
Anyone else seen this symptom? Anyone else solve the problem where this was the symptom?
Anyone else seen this symptom? Anyone else solve the problem where this was the symptom?
Powelligator
New Member
I'd like to close the loop on this in case anyone out there also sees this weird problem. My mechanic found that the ground wire on the Crankshaft Position Sensor was questionable, he replaced it and soldered it up - and the problem is no more. Yep - just as we thought, a simple ground problem. I'm thinking as these Jeeps age out (the newest TJ is almost old enough to drink now) we're going to start to see more ground issues causing weird symptoms.
Similar threads
