Body Control Module/Computer Replacement
 

I recently had some strange electrical issues with my 02SS. The problem ended up being the BCM. I want to share my experience to help everyone save the $450 the dealer wanted to replace it. I did it for half the cost.

A rebuilt module can be purchased from your local auto parts store for $94 vs. the $250 from Chevrolet. Pretty easy to change also saving $120 hr. labor. There is 2 procedures you have to then perform.

Once you change the module the car won't start. All codes are stored in the old module. You have to perform a relearn procedure. Its time consuming but saves $$$ from dealer. Need a fully charged battery, also jump box or charger. Key will be on for extended period. Turn on the key and attempt to start the car. Leave the key in the on position for 30 minutes. After 30 minutes turn the key off for 10 seconds. Repeat this procedure 3 times. After the 3rd time off for 10 seconds the car will start.

After I got the car to start I still had the radio locked, security light, no interior dome lights, and an air bag light. You need to take the car to the dealer and they run the VIN and get the codes for the car build. They program the BCM with the codes and car is back to normal. They charged me $108 for this. Ended up total cost of $202 vs. $450 dealer quoted me.

Hey, Just wandering as to what kind of electrical problems you were having that lead to having to replace the BCM.

Body Control Module/Computer Replacement
 

My lights kept going from daytime to nighttime mode cycling constantly. Dash lights dim to bright and DRL on and off. No interior dome lights. There was a drain on my battery that would kill it if left idle more than a few days. After I replaced the module the problems went away.

My 2001 Monte does the same thing. It had a battery drain since day 1 I bought it used. Headlight display would come on every now and then. Lights go from day to night. My dome lights have always worked though no matter what. Also, my traction control and ABS would pop up once in a blue moon. Now, somebody had went underneath my monte and snipped the wheel speed sensor wire for the front passenger wheel. I guess they were trying to cut a brake line but cut that wire instead. I had found this out when Midas told me they spotted a cut wire(BTW, NEVER EVER go to Midas. They are F***ing retarted I swear:nono:) Anyways, I re connected the wires and my traction control/ABS has been displayed ever since and wont go away. I think its because of the BCM. I know mine is bad because if you pop the hood of your car and open up the top fuse panel and check the circuit labeled LEFT I/P 242 you'll see an abnormally high amp draw. I then checked the BCM circuit on the driver side in cabin fuse panel and sure enough it was the ONLY circuit drawing current overnight when the car is completly off. It would die in 2-3 days if I didnt drive it.

Now, as for the dealer and what they charge to reprogram a BCM, that is a COMPLETE rip off just to push a couple buttons on a keyboard and reprogram it. Can't you just go to the junk yard and pop a good BCM out of another monte and bring that to the dealer to be reprogrammed? I mean, it'll certainly be less than the 94 dollar rebuilt one at a store right? Figure no more than 20 bucks. Just my 2 cents there.

One last thing, I had changed my cluster gauge to the SS one(I think it looks alot better anyway than the LS:rolleyes:) and my oil pressure gauge does not work and never has since it was put in. Is this normal? Does the LS 3.4L engines have a oil pressure sensor? Should that gauge work with the 3.4L engines or is the gauge in the cluster gauge itself burnt/broken? It's been buggin me for awhile haha

Don;t think a used one will work.
 

I am told that the BCMs are a one time use item. They are programmed to the specific car. After you do the relearn procedure it will let the car at least start. All the symptoms you have it is possible you have a BCM from another car that hasn't had the car specific programming done to it. They put in all the security codes for the car (theft lock), and all the accessories that were on that VIN when it was built. I have had absolutely NO problems out of mine since. All the accessories work and can set for weeks and the battery stays charged.

BCM replacement.
 

Yeah, a lot of these GM body control modules are "one and done" as far as the VIN-writes/initial setups. You have to be careful too and answer all of the questions correctly during setup like "does the car have fog lights?" , etc. because if you answer it wrong, you have to go buy another BCM and do the setup all over again. Rock Auto has these 2000's Dorman BCMs for around $70 or so (not too bad.) I think they have the AC/Delco ones for about $120.

GM has a Tech2Win emulator that works with their MDI (factory tooling) and also with Drew Technologies Mongoose Pro GM 2 cable ($495.) The Tech2Win program is available from GM (acdelcotds.com) for $55 for a 3-day subscription to allow Tech2 functionality with Drew Tech's J2534 product line. You also can get a yearly Tech2Win subscription coupled with GM's SPS (Service Programming System) that allows for module flashing/replacements for $1395 for a year. You also can get GM service info (service manuals, wiring diagrams, access to TSBs, etc.) for $20 for 3 days or get SPS by itself for $55 for a 2 day subscription.

Here's the site that has information on Drew Tech's products and GM's Tech2Win program/subscription info:

www.tech2win.info

Bottom-line is you can get a MongoosePro GM II cable for $495 and get the Tech2Win subscription for $55 for 3 days and basically have full GM factory diagnostic capabilities for LOTS of GM cars like ours. That's a pretty affordable diagnostic solution for do-it-yourselfers!

DH

I am having a problem with my car similar to this issue.

I have a 2000 MC SS

I pulled into my driveway one day and the next thing I know, my car wouldn't crank. I replace the starter, but still nothing. Took it to a mechanic, and he told me that I needed a new ECM and BCM. Purchased remanufactured (I know this was a mistake now) parts, and had no problems reprogramming the ECM.

However, when the BCM is connected, the car automatically switches to Accessory mode, and doesn't recognize any of the others, no matter the position of the key in the ignition (OFF, ON, CRANK).

Does anyone have a suggestion as to why the car is acting as if the key is in the Accessory Position continuously?

NOTE: As for the BCM, I purchased a remanufactured part, but it has not been compatible with the car, so I just went ahead and purchased the BCM directly from the dealer - and yes, I was raped for it.

BCM issues.
 

Did the shop program/setup the BCM? If this isn't done a lot of times the car won't start or recognize the keys/key fobs, etc. You (or the shop tech) would need to see what your year car requires (in service information) as far as PCM/BCM replacement/setup.

DH

What could this bee when my high beam out message is on and high beAms stay on while my low beams are dim. The service vechile light was on but went off. What could this be?