I was doing my 4th Dash Removal and first one for a LS1 all the others were LT1, not that I thought it would matter. After doing it for HVAC removal on a 99 Camaro we reassembled the the dash and noticed the windows would not roll up. When the Key was foward if you hit the lock button to "Lock" the Courtesy bell would start ringing faster, you turn the key off, the locks work fine. Either way windows wouldnt work. Everything was checked and doubled checked, nothing was cut and I had never had this problem before. I posted earlier and someone said it might be the BCM, so I have a 97 that we borrowed if from. We plugged it in and the windows and door locks work fine, but the car wouldnt start, most likely I am assuming this is from the VAT Key System.

I searched and am curious can any other thing cause this are they that sensitve internals?? Is our only choice to buy a new BCM off ebay or GMPartsDirect?

On a Side note does the BCM also control the radio power and such?

Here are a few pics that I am curious to what they are.

What module or control is this? Below


Double Plug in: What is this one?Below



Here is 2 relays black and gray, I believe the gray controls the alarm



This has some type of Phone RJ Connection on it, what is that used for?



Any help appreciated.

 

First one looks like the remote reciever for the keyless entry. Not Sure from photo I have to see in person could be a relay for locks or the windows same with number two. Three are the fan relays for the A/C not sure if they are all for the A/C or not but I know where they are mounted and I am sure that is off it the right area. The Blue and White pulg on the far right are the plugs feeding the A/C controls and all the gauge cluster stuff from the computer and all that.

 

Thanks for the helping!

Anyone else think they know the other ones?

 

RJ connector is not factory. Looks like an aftermarket alarm system & wiring. GM wouldn't use RJ connectors (not their style ).

Double connector item is DRL module / turn signal / auto headlight.

 

You guys have any thoughts on how that BCM took a dump?

 

Yeah, I hope we can get this figured out bro. Rolling around with no radio or windows is rough. Ha.

 

I have had a similar issue ever since I pulled my dash and took the heat and junk out.

my car keeps blowing the fues that controls the power locks and interior lights, everything else is fine but it won't let the power locks or cabin lights live for more than like 5 minutes if i put a new fuse in. i've always assumed its BCM related.

i just haven't bothered to do anything about it since its not that big of a deal on a non daily driven car.

 

Hmm, so you have no power locks now? My windows don't move. I have to figure this out. Does your radio work? Mine doesn't.

 

This is from one of the techys off Cz28
"The BCM will also control the retained and accessory power for the radio, windows and such (which some of you already found"

So we know thats why your radio doesnt work. Let me know what Ivan is gonna do for ya on that.

And Buy some damn 28s!!

 

Did you check the express down module by the firewall, and on top of the trans tunnel? If everything BUT the windows works, that would be a possibility (for the drivers side at least).

Beyond that, look over your radio and window circuits for a wire with a bare spot. Shouldn't be too tough with everything pulled out already.

 

Yeah, I know. I just don't have the gear for them. I'd need a 4.10 for motor and/or juice. I'm calling Ivan now. Thanks.

 

We didnt check the express down we will have to try that too.

 

Your on crack you dont need a 4.10

 

I had a friend look up a part number for the BCM with my VIN and then he checked for his 02 SS and a different part# came up? Are these year specific, VIN specific, or what? It's $130 for a new one and I want to make sure it'll fix the problem. Errrr. Help! Ha.

 

From the service manual it sounds like a RAP issue:

Retained Accessory Power (RAP) Description and Operation
The Body Control Module (BCM) monitors the ignition switch position, battery condition and passenger compartment door status to determine whether Retained Accessory Power (RAP) should be initiated. When the ignition switch is in the ACC or RUN/ON position, the BCM closes the RAP relay and supplies power to the RAP circuit. If the ignition switch transitions from RUN/ON to OFF, the battery level is within the acceptable range and the passenger compartment doors are closed, then the internal RAP relay will remain closed. When the RAP relay is closed it provides power to the:

Power windows
Power folding top
Radio.
The BCM module turns OFF the RAP function and opens the internal RAP relay when one of the following conditions are met:

The body control module senses the opening of a door in the passenger compartment
The body control module receives a message from its internal timer indicating the end of the RAP period after 10 minutes
The transition from OFF to RUN/ON or ACC of the ignition switch.

--------------------------------------------------------------------------------
and after reading through everything it sound like you needs to connect with a Tech2. Get the DTC's from the BCM and reset them as mentioned here:

Body Control Module (BCM) Programming/RPO Configuration

Important
Any new BCM will automatically program to the resistance of the ignition key being used at the first ignition ON cycle. This can only be done once for the life of the module.
The BCM can only be programmed to one ignition key resistance. All ignition key resistances must match.

A new BCM is not programmed. Before the system will function properly it must be programmed to the code that matches the customer's keys.

Insert one of the customer's keys into the ignition cylinder and turn it to the ON position. Start the engine at this time in order to verify system operation.
Observe the SECURITY indicator lamp for the following conditions:
The indicator lamp lights steadily for approximately 5 seconds and then goes out. This indicates that the BCM is programmed properly.
The indicator lamp flashes at a rate of one flash per second until the ignition is turned OFF. This indicates that the BCM did not program and the system should be checked for a fault. Refer to Diagnostic System Check - Theft Deterrent in Theft Deterrent.

Important
After programming, perform the following to avoid future misdiagnosis:


Turn the ignition OFF for 10 seconds.
Connect the scan tool to the data link connector.
Turn the ignition ON with the engine OFF.
Use the scan tool in order to retrieve history DTCs from all modules.
Clear all history DTCs.


These are excerts from the factory service manual...hope it helps.

 

Wow, that's A LOT of great info. Thanks for posting. I hope this new BCM fixes the problem. So if I read correctly, a used working BCM will not work on my car because it's already been programmed for a different key resistor once and only once. I have to buy a brand new one from GM and set it for my key. It's also very likely that my RAP relay is shot too, or is this simply a side effect of a bad BCM? Thanks a lot.

 

Where is the Rap located at?

 

Good question...........?

 

I'll get for ya later tonight....what happened to your original BCM????

 

The RJ connector appears to be a aftermarket gear correcting module. You will notice most likely, you can disconnect it, and plug the 2 factory white connectors back together, as the car would have come from the factory.

The 2 connector one is the DRL/Turn Signal control module.

the one with a 5 pin connector, 4 wire is the 1218-2126 is the window roll down module.

the relays, im not sure what they're for.

hope this helps.

Ryan