Hello folks, and thank you in advance to take the time to read through this. This morning, while coming home from work, my check engine light was on. No biggie, after my second job I'll go home and throw my OBD2 code reader on there. I get home later today and stick the reader on there. It cannot link to the truck's computer. I try again, same thing. I turn off the ignition and notice that my radio is still on (longer than the usual delay). My ignition power is still on and will not go off. I disconnect the negative battery terminal for about 5-10 minutes. When I proceed to turn on the ignition again, now my check engine light, ABS, airbag, and battery lights stay on--even when I start the truck and it's running.

In addition to that, the power windows, locks, radio, and gauges do not work (with the exception of the tach and speedometer which do work). Obviously the OBD reader still cannot connect.

I have tried:

- Disconnecting negative terminal for 30+ minutes,
- Turning IGN on, removing ECM fuse for 5 minutes then replacing for a hopeful reset
- checking every possible fuse (all the IGNs, ciglighter, ECM, any other possible acronym fuse) that would have to do with the ECM.
- putting the truck in the timeout corner
- Something I saw on a random forum where you turn IGN on, press the gas pedal all the way for 15 seconds, then turn IGN off and release pedal
- Searching every corner of the interwebz

I am stumped and open for suggestions. Again, thank you in advance.

 

Oh, and here are the specs:
2006 Silverado 1500 5.3L V8, Z71 4x4 (LT I think?) Crew Cab; about 101.5k miles

 

So... I came across this thread while eating breakfast (before heading to the dealer): Chevy Silverado and GMC Sierra Electrical and Computer Questions - Car Forums - Edmunds

The problem was a bypass module installed with an aftermarket radio (for the chime and such). Removed it and everything magically worked... like instantly.

Hope this thread can help someone else in the future.