etdobbs

My C6 has been experiencing electrical issues (mainly will not start) when parked outside in temperatures above 85°. It can drive and does not die in any temperature. The issue arises when shut off and let sit for a couple minutes. It will not restart until it cools off (either later in the evening or if I push it in the garage).

Symptoms when above ~85°:
- doors and trunk will not electronically open
- when trunk is opened manually, alarm will not go off
- FOB alarm button does not work
- FOB not recognized in glove box slot
- ignition and accessory buttons do not respond. (no gauge response and no DIC "FOB not detected" message)
- "Service Vehicle Soon" apppeared on DIC once when it cooled off enough to start.
- trunk and dome lights will work
- on/off button will show radio time
I am still working diagnosis.

When it cools off, everything comes back to life. Alarm will go off, ignition will be on. Whatever buttons I touch to get it started seem to be remembered. It will startup immediately and have no issues.

My current plan:
- further inspection of battery (~8 months old)
- check the 12 main frame ground points (nice write ups on this by forum members)
- inspect connections at BCM, RCDLR, and instrument panel
- when above 85°, remove RCDLR and instrument panel and bring inside to cool them down.

Questions:
- has anyone experienced this type of issue before?
- are there any other modules or areas that I should be considering?

Thanks in advance for your input.
Tim..

etdobbs

I think I found it. Thanks for looking.

Got uid0

what did you find

etdobbs

After much trial and error indicting the systems mentioned above, I believe one of my serial data wires was selectively contacting a 12V+ wire. The source was at the black connector of the gauge panel. All cleaned up and running good over the last three 95°+ Iowa days.