Forum Fam,
I’m completely stumped. I have a 2007.5 Sierra Denali awd 6.2L, been a fine running truck only 118k miles on the clock. Early last week I went to start my truck and interior lights came on, etc but no crank. It’s a new battery and fully charged. I pulled the inner fender, I’ve got power at my starter via the battery cable. However am NOT getting power to the pink wire via the relay.

I can jump the starter relay and the truck turns over but does not start. I don’t believe Im getting any power to the relay from the yellow wire from the ECM (pin 86).

I thought maybe ignition switch, but when I turn key to start position, everything else shuts off like it should. I know there is a park neutral switch in the Tranny as well, but idk.

When this problem started, I also noticed a random “service airbag” light on my dash. I know it’s electrical but it had me stumped so I had it towed to a shop with a full scanner, they spent a week and they are stumped.

Maybe a bad ecm? I just don’t know what to do. Any ideas?