PCM Probelms/Auto Start/Check Engine

[Jvendi1003]

Hey everyone, I recently got a 2024 Sport S, after 300 miles my check engine light when on and my auto start/stop displayed a problem, brought it to the dealership, they stated it needs a new PCM, after 2 weeks the PCM just got replaced and the check engine light is still on. They now are awaiting a response from Chrysler as to what the problem may be. Has this happened to anyone?

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[jhackathorne]

Did they check the codes for the CEL? That should lead them in the right direction….

 

[Jvendi1003]

Did they check the codes for the CEL? That should lead them in the right direction….

They did and it led them to swap out the PCM but the CEL remained.

 

[JL ME]

Hey everyone, I recently got a 2024 Sport S, after 300 miles my check engine light when on and my auto start/stop displayed a problem, brought it to the dealership, they stated it needs a new PCM, after 2 weeks the PCM just got replaced and the check engine light is still on. They now are awaiting a response from Chrysler as to what the problem may be. Has this happened to anyone?

This happened to me two times at 4,000 miles and at 8,000 miles.
Both times I disconnected the batteries to clear the faults and went on my way.
I now have 12,000 miles on the jeep and haven't had the problem since.
The only other thing I did the second time was to push all the fuses down to seat them. They were not all seated properly.

 

[Jvendi1003]

This happened to me two times at 4,000 miles and at 8,000 miles.
Both times I disconnected the batteries to clear the faults and went on my way.
I now have 12,000 miles on the jeep and haven't had the problem since.
The only other thing I did the second time was to push all the fuses down to seat them. They were not all seated properly.

This happened to me two times at 4,000 miles and at 8,000 miles.
Both times I disconnected the batteries to clear the faults and went on my way.
I now have 12,000 miles on the jeep and haven't had the problem since.
The only other thing I did the second time was to push all the fuses down to seat them. They were not all seated properly.

Appreciate your input, hopefully Chrysler advises them something simple such as that.

 

[jhackathorne]

They did and it led them to swap out the PCM but the CEL remained.

Did they scan it against after replacing the PCM? If the CEL is on still it should be giving them codes even after replacing the PCM.

 

[Jvendi1003]

Did they scan it against after replacing the PCM? If the CEL is on still it should be giving them codes even after replacing the PCM.

They relaced the PCM yesterday and said the CEL was still showing with the same error message on the auto start/stop. They recalibrated the computer system and still nothing. The code has not changed either so they’re stumped.

 

[Jvendi1003]

Quick update for anyone reading this, there was a loose wire that was not grounded which fried the PCM due to over heating.

 

[Bob Burd]

Quick update for anyone reading this, there was a loose wire that was not grounded which fried the PCM due to over heating.

This makes no sense. Loose wires don't cause modules to overheat.

 

[Jvendi1003]

This makes no sense. Loose wires don't cause modules to overheat.

They told me the wiring not being grounded properly was causing a short which lead to overheating which in turn fried the system. Doesn’t sound right to me either.

 

[Bob Burd]

So did they put in a second PCM after fixing said loose wire?

 

[dstevens]

Bad grounds can easily fry electronics. When the ECU sinks current, for example when grounding an output solenoid, if the ground connection between the ECU and vehicle is bad then two things can happen. The ECU can ground through other sensors or outputs and damage the ECU or the sensor. However the other thing which happens is worse - the ground plane in the ECU becomes elevated in voltage and then components in the ECU are reverse polarized. eg if the ECU ground plane floats to 10V then the 5V rail is now -5V. This will burn out components in the ECU instantly.

 

[Bob Burd]

This is nonsense.

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