03 Avalanche

DENNIS KEEL

MEMBER
2003 CHEVROLET AVALANCHE
V8
4WD
AUTOMATIC
260,000 MILES

My chevy avalanche recently became possessed. When I was driving my door locks began to flicker back and forth my message center said service brake system, reduced engine power, abs was going off, engine seemed to be cutting on and off. Now it will run fine for about ten or 15 minutes and begin to act up again, the code I got out of t was pcm to tacm. I replaced the pcm with no luck, so before I start throwing more expensive parts at this thing I need some help. Severall others in different forums have described this problem but havn't found a solution plesas help

1 Reply

HMAC300

MECHANIC
48,601 POSTS

Check your battery and charging system. When a battery goes bad it screws up all your electronics. This includes cleaning your battery terminals and cleaning the grounds going to tehengine and the ground going from the battery to the body. It can always be something else but this is an easier better place to start. Most auto parts stores can check your battery to see if it's any good. Also there is an old TSB that the wire harness under the driver's seat can be chafed or hitting against the seat bracket and it may be causing problems with driveability isssues. It would need to be rerouted. Unfortunately I can't send a picture of this due to that part of the site not being available for a few more days. This effects the body module which operates thedoor locksforone.