2012 Intermittent DTCs when charge cable connected, car immobilized. BDU relay jct block?

Symptoms
Plug car in:

• Windshield dashboard light remains yellow. No chirp to indicate charging.
• If open the door, DIC says "Not Able to Charge".
• After 15m or so, I receive a text message from OnStar saying "Your 2012 Volt is not charging due to an interruption..."

After that, if I turn the car on:

• DIC says :"Initializing Please Wait to Shift" for much longer than normal (10s?)
• Then dashboard comes up with some abnormalities:
  • Check Engine Light on
  • Gas and Electric ranges are grayed out
• Car is immobile...no traction power in any gear
• If turn car off with foot on brake pedal, it power cycles instead of turning off
• Codes set are P1EBD "Charge System Contacts Stuck Open", and P1E00 "HPCM2 req MIL illuminated"

In this above state, the car cannot be driven. Also the car won't attempt to charge. I have cleared codes with my OBDlink interface to restore driveability.

Playing with the car in the above state (clearing codes, setting them again with the cable, driving etc.) caused two other codes to show up: P0D22 "Battery Charger Output Current Performance", and P0AF8 "Hybrid Battery Pack Voltage Sense Circuit Correlation"



Other Notes
12V battery recently changed.
Symptoms have been reproduced on multiple charge cables (including 120V in 8A mode)
Dealer was unable to reproduce the issue so far. Will try to get it to misbehave for them next week.


I'm wondering if anyone has had symptoms like these? How were they addressed?

Thanks, russella


I don't see too many other complaints that seem to match my symptoms. I think what I'm seeing exactly matches what whiteelectric described in his thread from a few years back. Solution was to replace the relay-junction block/BDU:
https://gm-volt.com/forum/showthrea...pushed-dash-lights-work-Help!&highlight=p1ebd

fishhawk had a saga similar to this...he replaced his 12V battery which seemed to sort it out, but then didn't. From that thread it seems he finally had to get the BDU replaced to sort it out.