Originally Posted by RHODEEHO
no faults recorded in computer.
That actually surprises me greatly - I would be looking at power delivery (electrical) as almost nothing else would explain the ECU taking a dump and not recording it. Heck, fault codes in the C7 are even timestamped so I'm aghast that the ECU wouldn't log a failure - thus I presume that it *COULDN'T* log a failure.... which leads to power/ground questions.
Were I the technician, I would have grabbed hold of every connector I could find and given it a good wiggle, removed and reseated all ECU connections, and any other power distribution connectors I could reasonably easily reach.
I hope you got hit by cosmic rays or some other such gremlin, but it does make me nervous. OTOH, my HID igniter circuit failed exactly one time (in the dealership parking lot no less) throwing the dash indication and everything, then went away silently upon restart and hasn't reappeared (yet) in the intervening decade+.
When the original failure occurred, did you shut the car completely off and restart it? Kind of like a personal computer - shut down, wave hands and pray to the electronics gods, then restart?