GM Repair Problems? Ask GM Repair Expert Now.
I have seen this condition before. It usually indicates a communication problem in the system's can network.
The most common cause if the communication loss is corrosion at the PCM connector under the battery. You can disconnect the battery and unplug each wiring harness and check it for corrosion.
Let me know what the connectors look like (if you plan to work on it yourself).
It sounds like there is definitely an electrical problem somewhere in the communication network. Did you see anything unusual at the PCM?
Sorry, I'm back. I'm looking up schematics to see where to check next.
Can you check to see if there is 60 ohms at data link between serial data wires; most of the time they are tan and tan and black?
I think you may have a bad BCM.
The Body control module. It works with the PCM to control components such as the seat, windows, lights, door locks, etc.
Here is a diagram that shows the location of the BCM. It's right above your feet under the dash. You can unplug all of these connectors also and check for signs of damage or water intrusion. It never hurts to spray the connector ends with WD-40 and then plug them back in and see what happens. A bad BCM and a loose BCM connector will give the same symptoms.
I just wanted to check and see if you need any additional information.
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