Stereo & Electronics - body control module

what all does the bcm control exactly??

The BCM controls the keyless entry system, content theft deterrent system (alarm), vehicle theft deterrent system (VATS), audible warnings and chimes, retained accessory power (RAP), power door locks, hatch release, and the interior courtesy lights.

vehicle theft deterrent system (VATS)
VATS = Vehicle Anti-Theft System
:P

Yes, but the service manual lists it using the generic "vehicle theft deterrent" followed by the GM corporate-speak version (VATS) so I just followed their lead. I knew when I typed it that somebody would point out that the acronym didn't match - thank you for meeting my expectations. :jest:

is there a way to bypass the bcm so that it retains keyless entry funtions hatch and couresy lamps

maybe i should explain the car was a v6 car and the ls1 now runs off of a stand alone harness and basically the bcm is in my way and i would just remove it if i knew what it controlled. your telling me if i remove it i figured keyless entry was out, but the door locks and hatch is that just the keyless entry side of will the switches in the car no longer work if they are removed? what is (rap)

The BCM actually controls the door locks - without it the switches wouldn't do anything. The same applies to the hatch release although that would be a little easier to work around.

RAP is Retained Accessory Power - the function where the radio and windows will still have power for about 10 minutes after shutting off the ignition or until a door is opened. You could bypass that but you would have to rewire the power for the windows and radio.

There is no way to bypass the BCM while retaining keyless entry since the receiver is built into the BCM. The courtesy lights could be rewired but it would take some doing since the door switches only signal the BCM to turn on the lights - they don't directly control the lights like they used to in older models.

thanks that is what i needed to know

I knew when I typed it that somebody would point out that the acronym didn't match - thank you for meeting my expectations. :jest:
:lol: You're Welcome. :cheers:

to open up a semi-old thread. I want to tie my radar into the reading lights on the rearview mirror. With the BCM holding power to that item using the RAP, should i worry about it killing my battery? Once i turn off the car and open the door, close it, and lock the car there shouldnt be any power to the radar right?

to open up a semi-old thread. I want to tie my radar into the reading lights on the rearview mirror. With the BCM holding power to that item using the RAP, should i worry about it killing my battery? Once i turn off the car and open the door, close it, and lock the car there shouldnt be any power to the radar right?No, the power will continue for several minutes after you close the door (I think it's 10 minutes but I could be wrong). The map lights are not part of the RAP circuit. They are supplied with battery (constant) power and the power is only cut off by the BCM after 10 minutes as part of the battery saver function. The idea is to prevent the battery from running down if you leave a door open.

Why not just take a few minutes and run an ignition-controlled power wire (say, from the IGN port in the fuse panel) up the A pillar and across under the headliner?

Aren't the airbags/SIR sytem also controlled by the BCM (or are they run through the PCM)?? :confused:

Aren't the airbags/SIR sytem also controlled by the BCM (or are they run through the PCM)?? :confused:No, neither - the airbags are controlled by a separate module under the console behind the shifter.

Thanks WhiteBird, i'll keep that in mind when i decide which route to do. Im not electrically inclined so we'll see.