Hello all. I’ve been having electrical issues with my 2002 Z06. The codes don’t always happen. But I’ve noticed they show up more often right after I take the car off of a trickle charger. I cleaned the negative battery ground, as well as the two on the in the engine bay on the frame rails behind the headlights, and the ground under the master cylinder. I attempted to remove the the grounding bolt by the drivers side foot well but don’t have any tools to get into that small of a space (ratcheting wrench wouldn’t fit) so I sprayed it down with some electrical cleaner. I didn’t unfasten any of the pin connectors because I couldn’t figure out how to separate them without breaking them.

I then went for a drive. For about 15-20 minutes everything was fine. Stopped at a light and then the radio, HVAC both quit as well as the “service vehicle soon,” ABS, TCS warnings came on. About a minute later I got the HVAC and radio back while driving it home.

so I took it to a shop because I can’t figure it out, nor get the pin connectors separated or remove and that driver footwell ground bolt. The day of, I unhook it from the trickle, get the “service vehicle soon” ABS and TCS signs. Go to a restaurant and meet my ride back.

after the restaurant to drive to the shop, no codes, nothing.
shop calls me today and says 🤷‍♂️ “we don’t see anything. Sounds like your BCM is going out” and recommended for me to go to corvette world in Dallas.

to me it sounds like a ground issue but I’m a shade tree mechanic so what do I know. I appreciate you taking the time to read this and thank you for your input. The codes I have (but don’t always all show up)

BCM B0432
SDM U1040
IDC U1040
PCM P1571
HVAC B0332 B0337 B0361 B0365

 

Drive it with a scan tool hooked up and record the outputs. That should give you some clues.

 

Could very well be your Ignition switch, or bad electrical connections related to the Ignition relays in the fuse box.

 

The HVAC Module and Radio are fed off the same circuit through the ignition switch…if you have a DVOM and know how to use it this can be confirmed that the switch may be faulty.

 

do you think the ABS, TCS and “service vehicle soon” are also connected? Those were showing up a few weeks before the radio and HVAC. Or do you think those are the EBCM?

 

I don’t know if your P1571 is a current DTC but the 5 volt reference comes from the PCM…the battery feed for the PCM is on the same circuit as the HVAC and Radio…the PCM has an internal 5 volt regulator for all of the cars 5 volt reference circuits.

 

Update on my issues. Replaced the ignition switch and no more codes. A/C and radio back to working normal as well.

thank you for everyone’s help.