Body Control Module (BCM)
01-31-2015, 05:24 PM
#1
Instructor
Thread Starter
Body Control Module (BCM)
I have been hearing a lot of horror stories about the Body Control Module or BCM on early model C5's. I own a 1999 C5 Convertible with 26,000 original miles. Can someone give me some info about this ? Can it happen anytime or do I need to look for it to happen around a certain millage or certain conditions ? Are there any signs that the BCM is going bad? Hate to be on a road trip and it go out.
01-31-2015, 05:33 PM
#2
Le Mans Master
I think you're confusing the BCM (body control module) with the EBCM
(electronic brake control module).
The BCM is programmed to the specific car and options (it can be reprogrammed if swapped ).
The EBCM is the same for all models 97-2000.
They no longer make the early year EBCMs and they are not repairable under most circumstances.
Later model EBCMs (2001-2004) are often repairable.
As for what you can do to preserve your working EBCM, I have no idea.
(electronic brake control module).
The BCM is programmed to the specific car and options (it can be reprogrammed if swapped ).
The EBCM is the same for all models 97-2000.
They no longer make the early year EBCMs and they are not repairable under most circumstances.
Later model EBCMs (2001-2004) are often repairable.
As for what you can do to preserve your working EBCM, I have no idea.
01-31-2015, 06:07 PM
#3
Race Director
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St. Jude Donor '16-'17,'22,'24
Not completely accurate. There is an EBCM that is specific to the 97 and first half year 98's that had the EBCM mounted in the rear at the back of the differential.
In mid year 98 GM began offering Active Handling as a chargeable option. The EBCM's available on cars starting in mid 98 were 2. One if you have Active Handling ( referred to by many as the V model) and one if you did NOT have AH. The EBCM was relocated to the front frame rail under the alternator. The EBCM's for cars from mid 98 through 2000 remained at 2, one for cars with the AH RPO and one for the non AH cars. The EBCM's for the very early cars are not interchangeable with the mid 98 to 2000 and vice versa.
The EBCM is the electronic brain that controls the anti lock brake system. When it fails you loose the anti lock brake feature (brakes continue to function) and any feature that depends upon the anti lock brakes such as Traction Control and Active Handling.
In mid year 98 GM began offering Active Handling as a chargeable option. The EBCM's available on cars starting in mid 98 were 2. One if you have Active Handling ( referred to by many as the V model) and one if you did NOT have AH. The EBCM was relocated to the front frame rail under the alternator. The EBCM's for cars from mid 98 through 2000 remained at 2, one for cars with the AH RPO and one for the non AH cars. The EBCM's for the very early cars are not interchangeable with the mid 98 to 2000 and vice versa.
The EBCM is the electronic brain that controls the anti lock brake system. When it fails you loose the anti lock brake feature (brakes continue to function) and any feature that depends upon the anti lock brakes such as Traction Control and Active Handling.
01-31-2015, 06:25 PM
#4
Instructor
Thread Starter
Not completely accurate. There is an EBCM that is specific to the 97 and first half year 98's that had the EBCM mounted in the rear at the back of the differential.
In mid year 98 GM began offering Active Handling as a chargeable option. The EBCM's available on cars starting in mid 98 were 2. One if you have Active Handling ( referred to by many as the V model) and one if you did NOT have AH. The EBCM was relocated to the front frame rail under the alternator. The EBCM's for cars from mid 98 through 2000 remained at 2, one for cars with the AH RPO and one for the non AH cars. The EBCM's for the very early cars are not interchangeable with the mid 98 to 2000 and vice versa.
The EBCM is the electronic brain that controls the anti lock brake system. When it fails you loose the anti lock brake feature (brakes continue to function) and any feature that depends upon the anti lock brakes such as Traction Control and Active Handling.
In mid year 98 GM began offering Active Handling as a chargeable option. The EBCM's available on cars starting in mid 98 were 2. One if you have Active Handling ( referred to by many as the V model) and one if you did NOT have AH. The EBCM was relocated to the front frame rail under the alternator. The EBCM's for cars from mid 98 through 2000 remained at 2, one for cars with the AH RPO and one for the non AH cars. The EBCM's for the very early cars are not interchangeable with the mid 98 to 2000 and vice versa.
The EBCM is the electronic brain that controls the anti lock brake system. When it fails you loose the anti lock brake feature (brakes continue to function) and any feature that depends upon the anti lock brakes such as Traction Control and Active Handling.
First thanks for info.
So mine being a 1999 is the EBCM repairable/replaceable? Is the active handling the same as where you can set it for competition or stock setting button on console? is that what your talking of ? I have always heard when it went out you were domed.
01-31-2015, 09:10 PM
#5
Instructor
Thread Starter
If your car has Active Handling there will be JL4 listed on the list of RPO's on the inside of the glove box door. If the EBCM is what actually fails then generally the only repair for your car will be to find a used replacement EBCM that has not failed.
BUT, if you get the "Service AH/TC" message displayed in the DIC, DO NOT assume that the EBCM has failed and is the cause. There are dozens of codes that can result in the EBCM being disabled and the message displayed in the DIC. If you get the message Pull and Post your codes in a new thread on the Forum. Many here on the Forum can help you determine if you have a repairable condition that will cause the message to go away or if the EBCM has failed.
BUT, if you get the "Service AH/TC" message displayed in the DIC, DO NOT assume that the EBCM has failed and is the cause. There are dozens of codes that can result in the EBCM being disabled and the message displayed in the DIC. If you get the message Pull and Post your codes in a new thread on the Forum. Many here on the Forum can help you determine if you have a repairable condition that will cause the message to go away or if the EBCM has failed.
Thank You very much.
02-01-2015, 08:58 AM
#6
Le Mans Master
The front mounted and rear mounted EBCM are the same unit. You are correct that there are two different units though, active handling, and non active handling.