zbgy1

Can you have dealer reprogram a used BCM from another car.I have a 99 C-5 and the old BCM got wet.I have a used one from another 99 from a wrecked car.I was told by the wrecking yard that you can open the BCM and pull the tape off one of the chips and pass a UV light over it and clear the program and then have the dealer reprogram the BCM to my vin code.Is any of this true?

lionelhutz

Yes, it can be done. It does not require taking anything apart. There are 2 things that need to be done. The BCM needs to be programmed to match the options in the car and the BCM needs to be matched to the car. If the new BCM came from a car with the same options then a dealer is not even necessary. If you want the procedure let me know.

Peter

zbgy1

Peter would you please send me the procedure to reprogram the BCM. Thanks Billy

dougbfresh

The dealer has to hook it up to their test equipment and I believe they download the code needed from GM directly with the VIN of the car. Knowing most dealers, they will tell you the BCM you brought them is JUNK and won't reprogram to sell you a new one.

hattitude

I just got a new PCM- Powertrain Control Module, as part of a warranty repair.

They had to download the VIN from a GM computer into the new PCM unit. I found out that if the VIN in the PCM, doesn't match the VIN in the Airbag control, the airbag will not work and will trigger the airbag trouble light.

Not sure if that's the same with the BCM.

FYI....

JVetthead

I just replaced 2 BCMs in both of my cars with used BCMs... Thanks Ike
1 I had to take to dealer for reprogram because of active handling which i dont have the other on the race car I did not have to take to dealer only had to do the security relearn..

lionelhutz

Here's the info from the service manual;

The service BCMs EEPROM chip must be programmed with the proper RPO configurations by using a scan tool. The EEPROM stores information regarding the vehicle options and point of sale. If the BCM is not properly configured with the correct RPO codes, the BCM will set default values for some systems, which could cause malfunctions in other systems. When the BCM is replaced, the BCM must be programed to identify the following information:

Country of Sale (US, Canada, Europe, Japan, etc.)
Real Time Damping (RTD)
Memory Options
Front Fog Lamps
HVAC (C60-Manual, CJ2-Automatic)
Active Handling
Auto Headlamp Control
Power Tilt/Telescope Column

The BCM sends password information to the PCM on the serial data line to enable fuel for Content Theft Deterrent (CTD) functions, therefore, the PCM must also be programmed to accept the new password sent by the BCM. The BCM programming procedure will enable the learn password mode for both the BCM and PCM. This mode allows the PCM to learn the new password sent by the BCM whenever the BCM or PCM is replaced. If the BCM and PCM is not properly programmed together, the vehicle will exhibit a no start condition and the PCM will store a DTC P1631.

When an ignition key or the BCM is replaced, the BCM must be programmed to accept the resistance value of the new or existing vehicle keys in order to allow PASS-Key® operation. When the BCM is replaced, the service replacement BCM is programmed to accept the first PASS-Key® resistance value detected. If the BCM is unable to detect a valid PASS-Key® resistance value, the BCM will never end the programming sequence and a DTC B2735 will set. The BCM can also be programmed to accept a new PASS-Key® code by completing the following BCM/PASS-Key® programming procedure:


Important:
Before proceeding with this programming procedure, check for proper communications between the BCM and PCM. If communications cannot be established, refer to the appropriate Diagnostic System Check for the system unable to communicate.

Maintain the battery voltage while the PCM is in the Auto Learn Procedure. Follow this procedure exactly as indicated or you will have to repeat the procedure from the beginning.


Manual Programming (Domestic/Canada Only)
Using a Tech 2, select New BCM Setup and program the BCM with the correct RPO code configuration. [this is for the stuff above]
Turn ON the ignition leaving the engine OFF for 11 minutes.
Turn OFF the ignition for 30 seconds.
Turn ON the ignition leaving the engine OFF for 11 minutes.
Turn OFF the ignition for 30 seconds.
Turn ON the ignition leaving the engine OFF for 11 minutes or until DTC P1630 sets.
Turn OFF the ignition for 30 seconds.
Turn ON the ignition leaving the engine OFF and wait 30 seconds.
Attempt to start the engine. If the engine does not start, Refer to the Powertrain On Board Diagnostic (OBD) System Check in Engine Controls.

Important
Performing this procedure may cause a DTC P1630 to set. If a DTC P1630 sets, turn OFF the ignition for 30 seconds, then turn ON the ignition. If the DTC P1630 does not clear, Refer to Powertrain On Board Diagnostic (OBD) System Check in Engine Controls.

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There are other procedures that are used with a Tech2 or a Techline Terminal but if the options listed are the same for both cars then you should be able to just do the key-on key off as listed and be good to go.

Peter