Ok, OS12606961 Z71 4WD avalanche, after loading .CAX file for lean cruise did a full flash as required everything seemed good, appeared to take it, timer count down etc.

Went out to start and nothing, everything comes on with lights etc, fuel pump now staying on, relay continues to click, V2 says PCM not seen and when trying to turn truck over nothing happens.

Key off Onstar light green, key on Onstar light red.

Talked to JoeCar, battery disconnected now, pulled the INFO fuse under hood( forum says its the on star system fuse) to try and reset PCM.

Don't no what happened as I've been doing normal flashes for tuning and everything working great, also full flash been working on 2000 vette with no issues, reconnected to vette to verify cable still good, works perfectly.

What happened, what do i need to do to reprogram the previous calibration that worked before .cax

thanks Mike