Mechanics

CHEVY BODY CONTROL MODULE

2004 Chevrolet Impala

Electrical problem
2004 Chevy Impala 6 cyl Two Wheel Drive Automatic 120000 miles

My 2004 Impala will not start. I have replaced the starter and starter relay. I have found references to bad terminals on the body control module. I cannot find this part in my repair manual. Where is it located on the car? Also, is it something I should try to check myself, or should I take it to a mechanic?
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Oran0007
November 6, 2008.



Your BCM is located on the left hand side of the steering column.

If you want to replace the BCM, you will have to have the new BCM programmed at a chevy dealer. You can't do it yourself. Once it is programmed though it's only a matter of swapping the BCM.
However, before you spend money on that, make sure your problem is not elsewhere.

Does your car crank or is it silent when you turn the key?
Is your security light on?
If your car cranks, have you checked for sparks and fuel?

Tiny
RenaudTN
Nov 7, 2008.
Thank You. When I turn the key, there is no cranking, even with a brand new starter. I read that sometimes the terminals on the BCM corrode, and can cause this.

I don't need to check for fuel or spark until I can get it to crank right? Hopefully I will be able to fix it this weekend.

Tiny
Oran0007
Nov 7, 2008.
That's right, before you can check for a fuel or spark related issue you first need the car to crank.
I forgot to ask, but you checked your battery to make sure it was good and the cables were clean and tight right?

If you replace the starter and starter solenoid, but the car still doesn't crank at all, I'm thinking your problem is either a bad ignition switch, park safety switch, or brake pedal safety switch.

Check for voltage at the solenoid; if you get 0, suspect one of the problem mentioned above.

Tiny
RenaudTN
Nov 7, 2008.