BCM (Body Control Module) Issues?

**GMac1969** · 05-03-2012

Hello All...

Recently, when I turn on my headlights, I am experiencing a problem that looks like it would be an electrical short of some nature but in researching, I am finding it could possibly be a BCM (Body Control Module) issue. This is keeping me from passing Safety Inspection. I can get a hold of a BCM for fairly cheap but want to get some sound advice before purchasing and installing.

SYMPTOMS(1) Basic Headlights do not work.
(2) Lighting on instrument cluster flickers intermittently at a high rate.
(3) High Beams work and when they do...the flickering of Instrument Cluster goes away.

Fuses are all intact and good. Please help.

Thanks much..

**Rico** · 05-03-2012

What year?

**Rico** · 05-03-2012

Do you need schematics?

**Rico** · 05-03-2012

...

**BillBoost37** · 05-03-2012

I think the ign switch may have been blamed in the past as well. Have you pulled and looked at the headlight switch for any signs of heat etc?

**1ATony** · 05-03-2012

Originally Posted by BillBoost37

I think the ign switch may have been blamed in the past as well. Have you pulled and looked at the headlight switch for any signs of heat etc?

Yah you may want to check the back of the headlight switch to see if it's melted, and also the wires that go to it to see if they have heated up.

**GMac1969** · 05-03-2012

Sorry...1998 Grand Prix GTP.

**GMac1969** · 05-03-2012

I have not pulled the headlight switch but will do that. I didn't think about that as a possible reason in reading some of the other posts concerning the BCM that involved the same symptoms I am having. Thanks. Will get back with results and hopefully good ones...

**GMac1969** · 05-03-2012

Originally Posted by Rico

Do you need schematics?

Thanks so much for the offer but I don't think I will be getting that in-depth with this repair. All the wiring is in great shape with no signs or fray, wear or burning.

**Rico** · 05-03-2012

If you do then just let us know.

**GMac1969** · 05-03-2012

Originally Posted by 1ATony

Yah you may want to check the back of the headlight switch to see if it's melted, and also the wires that go to it to see if they have heated up.

Physically felt and inspected the back of the Headlight Switch and it is in good shape with no signs of heat or burns. I do, however, have an aftermarket set of headlights with Halo rings and such but have had NO issues with that. Maybe this might be the issue but there is no heating issue and all the bulbs work fine when working. I will replace with OEM headlights to see if this is the culprit and then look again at the BCM. Also, my inspection did not pass due to the Computer not being able to be read. (Another tell tale sign of BCM?)

**Rico** · 05-03-2012

Like Bill said the ignition switch may be causing your problem. A bad ignition switch may also cause the scanner to PCM communication problem.

I wouldn't rule out the DRL module as well IMHO.

**GMac1969** · 05-03-2012

Originally Posted by Rico

Like Bill said the ignition switch may be causing your problem. A bad ignition switch may also cause the scanner to PCM communication problem.

I wouldn't rule out the DRL module as well IMHO.

Thanks for all the tips. Time to get my hands dirty and see what comes up. This is absolutely great to have this feedback. Could have helped me a LOT a long time ago when I shelled out a crap-load of money to have OTHER people do the work that I could have done... :-)

**GMac1969** · 07-03-2012

Pulled and replaced Headlight Switch but that did not solve my problem. I figured it wouldn't since the switch was in perfect condition...no heat, no signs of melting, etc. Back to the question of the BCM. As well, if I purchase one, will it need to be reprogrammed?

**Rico** · 07-03-2012

Originally Posted by GMac1969

Pulled and replaced Headlight Switch but that did not solve my problem. I figured it wouldn't since the switch was in perfect condition...no heat, no signs of melting, etc. Back to the question of the BCM. As well, if I purchase one, will it need to be reprogrammed?

Just get a BCM at a local yard. Don't forget about the DRL module...may just want to pull the plug on it.

**brian1970** · 04-23-2013

what is the drl module

**brian1970** · 04-23-2013

i have a 2004 pontiac gandprix with the 3.8 motor it was stolden pretty muched stripped i put motor tranny computer from another car in it pretty much done but it wont engage starter i tryed to reset theft it wont or not sure thats it say starter shut down due to theft system took it to garage was told its the bcm maybe because computer wont hook up to it to tell whats wrong

**SlowNA06** · 04-23-2013

That's unrelated to the light issue. You want to perform a security learn for the new PCM. It takes a bit more than 45 minutes. Especially if you screw up and need to do it again.

Set the parking brake to disable the daytime running lights system to avoid draining the vehicles battery.

Try to start the vehicle by turning key to the START position.
Allow the key to fall back into the ON position. DO NOT TURN THE KEY TO THE OFF POSITION.
After no less than fifteen minutes turn OFF the ignition and wait for ten seconds.

Try to start the vehicle by turning key to the START position.
Allow the key to fall back into the ON position. DO NOT TURN THE KEY TO THE OFF POSITION.
After no less than fifteen minutes turn OFF the ignition and wait for ten seconds.

Try to start the vehicle by turning key to the START position.
Allow the key to fall back into the ON position. DO NOT TURN THE KEY TO THE OFF POSITION.
After no less than fifteen minutes turn OFF the ignition and wait for ten seconds.

Start the vehicle.