Hey, all, just a quick question here.....I'm thinking of replacing the BCM in my Cavalier, to, hopefully, fix my interior & trunk lighting issue. The main ? is, does the BCM have to come out of the same model year vehicle, with the exact same options on it? And, is there anything I need to do after I replace the BCM? Thanks in advance for any info!

look on rock auto or gm lookups like this to see if the bcm is the same. dont work on cavs much but i assume its like most of the other vehicles after around 2000 most use the same hardware/bcm but the vehicle and options and security are programed with the tech II at the dealer.
http://www.gmpartsdirect.com/catalog/frameset.cfm

Your Cavalier uses a Multifunction Alarm Module to control the interior lighting; here'* some info on it from the GM Service Manual:



Interior Lighting System Description

Multifunction Alarm Module

The multifunction alarm module uses an inadvertent power control in order to supply power to the following lamps:

The left front door jamb switch turns on the interior lamps through the multifunction alarm module. This is done by grounding circuit 394. When the left front door is opened, the switch closes. This action grounds and blocks the input to the module. The module then grounds the courtesy lamps and the header lamp in order to turn the courtesy lamps and the header lamp on. The following switches turn on the interior lamps by grounding the circuit 395 from the multifunction alarm module:

The panel dimmer switch provides a ground circuit for the interior lamps. This action turns on the interior lamps independent of the door switches.
The remote control door lock receiver grounds the interior lamps for approximately 40 seconds when one of the following conditions apply:

The multifunction alarm module provides an interior lamps-on delay after the left front door has been opened. The lamps remain on until one of the following apply:

The 40 second lamps-on delay is sometimes reduced to 4 seconds. This reduction occurs if a front door is opened within 2 minutes after the ignition switch is moved out of one of the following positions:

The interior lamps will turn off immediately when the vehicle begins to move.
Voltage is applied to the multifunction alarm module at all times through the INT LAMP fuse. The multifunction alarm module applies voltage at all times to the alarm'* internal feature, the inadvertent power control. Voltage is applied to the multifunction alarm module through the ALARM fuse when the ignition is in one of the following positions:

Voltage is applied at all times to the cigar lighter through the CIG fuse.

Battery Run Down Protection

Inadvertent Power Control output of the multifunction alarm module applies voltage to the following lamps:

If the ignition switch is in the OFF position for more than 20 minutes, the output timer will shut off power to all of the above lamps. If the vehicle traveled less than 24 km (15 mi) since battery voltage applied to the module, the output timer will shut off the lamps after 2 to 4 minutes.
You may reset the inadvertent power control output by one of the following methods:

Power Output Diagnostic Mode

You may use a power output diagnostic mode in the multifunction alarm module in order to run a quick test on the operation of the following outputs:

The power output diagnostic mode activates after you perform all of following actions:

Before 15 seconds pass, perform the following steps:

During a normal operation, the multifunction alarm module will flash the interior lamps until the ignition switch turns OFF. If there is an internal short in the multifunction alarm module, the module will chime in the following patterns:

• Two chimes every 3 seconds means that there is a courtesy output failure.

Wow, that'* a lot of info, but, my car does not have any alarm on it.

Well, the Service Manual isn't showing a BCM in any of the lighting diagnostic tests, only this Multifunction Alarm Module. You can verify this by using the info under the "Power Output Diagnostic Mode" section.

I don't know what problems you're having with your interior & trunk lighting, but if you post it up I may be able to help.

Found it, #26 in this pic, and it appears to be behind the passenger side kick panel:

http://parts.nalleygmc.com/showAssem...&searchString=

I think that may help...lol....I was told from people in another forum I'm in, that, it was on the driver'* side, near the kick panel..

Is this module easy to get to?

I understand your confusion..the component locator in the Service Manual says it'* located, "At the right front of the passenger compartment" and the instructions say to "Remove the left sound insulator" to get at it, lol!

I've never had to remove one, so you'll have to let me know.

A closer look at the pic shows it'* actually under the dash rather than behind the kick panel, but it shouldn't be too bad to get at.

Keep in mind that replacing this module doesn't guarantee that your problems will be fixed. Spending some time checking circuits with a test light and a DMM can often save you time, headaches, and cash!

What my problem is, is that my interior & trunk lights do not work. They were tested by a friend of mine back in AZ sometime back, and, there'* power going to the connectors. It may be as simple as replacing the bulbs, I'm not sure, but, I'm going to try to do that ASAP & let you know.