I am in the middle of trying to solve what I believe to be a BCM failure with my 2001 Pontiac Aztek. I've got most of the problems experienced by many others on this and other forums. A/C, power windows, tailgate w/upper window, power locks and radio all not working, Also, my message center keeps alternating between "security" and "service vehile soon" messages.
In an effort to do my best to confirm that it is the BCM and not some other wiring or component issue, I've done some voltage measurements at my center console fuse panel for my above components that are not working and in all cases except one, I have 12 volts (approx) power at each fuse so if I am reading my wiring diagrams correctly, the next item to control the affected circuits is the BCM. In the one case I do not have voltage for the power windows, there is a RAP relay preceeding fuse (#35) and it is controlled by the BCM. I'm getting my information from "Power Distribution" wiring diagrams downloaded from my library's Automotive Repair Reference Center (ARRC). There was also a helpful article about what the BCM controls at mediawurks.com/images/issues/cnt_mo/TLcme.html#story6
(Motorola BCM article). After completing this effort and reading what I could find, I was convinced I had a failing BCM and obtained a new one from BrightAuto.com. I received AC Delco and GM Part# 15235418 which I am understand to be the most current unit available.
After installing, I started the car and was quite disappointed to see that absolutely nothing had changed. Every single item that did not work with the old BCM was still not working with the new BCM installed. It was almost as though I had reinstalled the old BCM. This was not possible because I had marked "old BCM" with a marker on the old BCM label. The other possibility is that it has to be programmed before any improvements will be noticed.
Seems there is a good amount of disparity between the results people are getting on this forum and also the Edmunds Townhall forum (topic = Pontiac Aztek Electrical Problems) after installing their new BCM. On the Edmunds forum, everything I read had people installing the new BCM before getting it programmed and it cared for almost all of the problems.....the only things not fixed were the locked radio and an airbag warning light.
I would appreciate hearing from others that could tell me that they also saw no improvements with their new BCM installed until they got it programmed by a GM dealer or other capable and trained mechanic. I'd hate to throw away another $80 to have programming done if it will not make a difference as perhaps I have a different problem.
Last, does anyone know of a good place to get all the wiring diagrams for this car? Even though I was able to get some from my library, there was plenty of wiring info not available......the biggest being the BCM inputs and outputs........the connector identification for the rear of the fuse panel (the large light gray and black.....and then the three connectors coming out of the BCM.
In advance, thanks for any help and information you may provide.