I just reflashed my PCM for a gear change and I can't get it started. I tried flashing it back to stock, no start. We got on a scanner, there is a crank signal but no injector pulse or ignition. Its looking like the PCM and BCM are not communicating and the BCM has failed! We think its related to the VATS, codes are 12,25,35,55. Its now at the GM Dealer, my buddy is a drivability tech, he is going to try a reflash on Monday. Is it possible and probable that something crashed when I did the reflash or one mother of a coinsidence? Thanks, Les.

 

I've seen bus get hung before, did you try the deal with key
on, removing both PCM fuses? See if the thing will talk to you
then? Try relink VATS after that?

 

I will tell my tech at the dealership to give this a try, I guess the next thing is an factory reflash? I will still need to do my own to recalibrate for my gear change. Any thoughts on why this has happened, is it due to the BCM? Les...

 

I hope this helps someone else out as I sure got lucky. My no start was due to a faulty start relay, the coinsidence was unbelievable! My tech buddy reflashed the ECM and no start! Checked the wiring diagram and swapped the relay for another and presto. This would have left me stranded one day and not easy to diagnose. The start relay is located in the under hood fuse box next to the cooling fan relay, Les...