As the title states, I have an 03 trailblazer ext with a 4.2L I6, Around 196k miles on the clock. I've owned the truck for a few years now and I've had this issue on and off but now is consistent.

Literally every time I put the truck into gear or into park and the autolocks are triggered, if someone hits the lock button, or if I roll the window completely up or down I'm getting a reduced engine power code for a p1271 (app sensor). I can just clear it usually and the truck will run fine until I have to put it back into park again.

I've now replaced: My battery My water pump along with the fan clutch My gas pedal (app sensor) Went over and cleaned all the chassis grounds Gone through the harness and inspected for any damaged wire Removed and cleaned the throttle body

But it's like everytime I'll think it's fixed like for instance most recently when I replaced the battery, because it might go weeks without it happening. But then out the blue seemingly it rears its head again and now it's a consistent issue. It's at a point where I just keep a cheap scan tool plugged in to clear the code upon start up. I was thinking about doing a new pcm but from my understanding I'd have to do a CASE relearn procedure that an expensive scan tool is required for. I'm at a loss at this point, any ideas?