Restore Full Control Over Your GM Truck’s Electronics
Is your GMC Sierra, Chevrolet Silverado, or other GM truck plagued by baffling electrical problems? One minute the A/C works, the next it doesn’t. The security light flashes randomly, or the power windows have a mind of their own. As a technician with over two decades of diagnostic experience, I can tell you that these aren’t separate issues—they often point directly to a single failing component: the Body Control Module (BCM). This module is the nerve center for your vehicle’s comfort and convenience features, and when it fails, it creates chaos. This replacement BCM, part number 20939137, is the definitive solution, offered with a professional cloning service to make your repair simple and effective.
A Technician’s Notebook: The Case of the Intermittent No-Start
A 2011 Sierra 3500 HD was towed to my shop with a frustrating intermittent no-start condition. The owner had already replaced the battery and checked the starter. The dashboard would light up, but turning the key did nothing. After hooking up my scanner, I found a slew of communication codes and a tell-tale B1001 for SDM mismatch. Instead of just throwing parts at it, we checked the main BCM grounds—a common weak point. They were solid. The issue was internal to the BCM itself; its logic board was failing, causing it to lose communication with the security and powertrain systems. A cloned BCM like this one solved the problem instantly, without a trip to the dealer. This is a fix I’ve performed hundreds of times on this GM platform.
Is Your GM Truck Showing These Symptoms?
- ✔️ Unresponsive or erratic power windows, door locks, or interior/exterior lights.
- ✔️ Complete or intermittent loss of HVAC and climate control functions.
- ✔️ An illuminated airbag warning light, often accompanied by DTC B1001 (Setup SDM Primary Key In BCM).
- ✔️ Security system malfunctions, leading to stalling, misfires, or a no-start condition.
- ✔️ Strange behavior from dashboard gauges or warning messages.
- ✔️ A variety of communication (U-codes) or body-related (B-codes) diagnostic trouble codes.
A Straightforward Guide to BCM Replacement
Our cloning service makes the electrical part of this job plug-and-play. The physical installation is just as simple and can be done with basic tools in your own garage.
- Safety First: Always begin by disconnecting the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Access the Module: The BCM is located under the driver’s side dashboard, typically to the left of the steering column. You may need to remove a lower dash panel for access.
- Perform the Swap: Carefully release the locking tabs on the multiple wiring harnesses connected to the old BCM and unplug them. Remove any mounting bolts or clips holding the module in place and take it out. Install the new module and securely reconnect all harnesses.
- Reconnect and Test: Reattach the negative battery terminal. Start your truck and verify that all body functions are restored—check your lights, locks, windows, wipers, and HVAC system.
- Address Warning Lights: If the airbag light remains on, the ‘Setup SDM Primary Key in BCM’ procedure is required. This is not a defect but a necessary security handshake that must be performed with a compatible high-end scan tool. Similarly, a ‘Brake Pedal Position Relearn’ may be needed on some models.
Disclaimer: While this is a common repair, procedures can vary slightly. We always recommend consulting a factory service manual for your specific vehicle.
Verified Vehicle Compatibility
This module is a direct replacement for part number 20939137 and other interchangeable numbers on a wide range of GM trucks and SUVs. It is guaranteed to fit the following vehicles:
ESCALADE EXT 10 Body Control (BCM); (under steering column), ID 25835966
SIERRA 2500 PICKUP 08-11 Body Control (BCM); (under steering column)
SIERRA DENALI 2500 11 Body Control (BCM); (under steering column)
SIERRA DENALI 3500 13 Body Control (BCM); (under steering column), ID 25835966
SUBURBAN 1500 10 Body Control (BCM); (under steering column), ID 25835966
SUBURBAN 2500 10 Body Control (BCM), (under steering column)
YUKON XL 2500 09-11 Body Control (BCM); (under steering column)
ESCALADE EXT 07-09 Body Control (BCM); (under steering column)
SIERRA 3500 PICKUP 08-11 Body Control (BCM); (under steering column)
TAHOE 07 Body Control (BCM); (under steering column)
YUKON 07 Body Control (BCM); (under steering column)
ESCALADE EXT 11 Body Control (BCM); (under steering column)
YUKON XL 1500 10 Body Control (BCM); (under steering column), ID 25835966
AVALANCHE 1500 08-09 Body Control (BCM); (under steering column)
SILVERADO 1500 PICKUP 08-11 Body Control (BCM); (under steering column)
TAHOE 09 Body Control (BCM); (under steering column)
SIERRA 1500 PICKUP 10-11 Body Control (BCM); (under steering column)
SIERRA 2500 PICKUP 13 Body Control (BCM); (under steering column), ID 25835966
SILVERADO 2500 PICKUP 09-11 Body Control (BCM); (under steering column)
SUBURBAN 2500 07-09 Body Control (BCM); (under steering column)
YUKON 11 Body Control (BCM), (under steering column)
ESCALADE 11 Body Control (BCM); (under steering column)
ESCALADE ESV 11 Body Control (BCM); (under steering column)
SUBURBAN 1500 07-09 Body Control (BCM); (under steering column)
AVALANCHE 1500 07 Body Control (BCM), (under steering column)
SIERRA 3500 PICKUP 07 Body Control (BCM); new style (smooth door skin), (under steering column)
SILVERADO 3500 PICKUP 08 Body Control (BCM), (under steering column)
TAHOE 10 Body Control (BCM); (under steering column), ID 25835966
YUKON 08 Body Control (BCM), (under steering column)
YUKON 09 Body Control (BCM); (under steering column)
SIERRA 3500 PICKUP 13 Body Control (BCM); (under steering column), ID 25835966
SIERRA DENALI 2500 13 Body Control (BCM); (under steering column), ID 25835966
SILVERADO 1500 PICKUP 07 Body Control (BCM); new style (smooth door skin), (under steering column)
SILVERADO 3500 PICKUP 09-11 Body Control (BCM); (under steering column)
SILVERADO 3500 PICKUP 13 Body Control (BCM); (under steering column), ID 25835966
TAHOE 08 Body Control (BCM)
YUKON XL 2500 07-08 Body Control (BCM), (under steering column)
SIERRA DENALI 07 Body Control (BCM); new style (smooth door skin), (under steering column)
SIERRA DENALI 1500 11 Body Control (BCM); (under steering column)
SILVERADO 2500 PICKUP 13 Body Control (BCM); (under steering column), ID 25835966
YUKON 10 Body Control (BCM); (under steering column), ID 25835966
YUKON XL 1500 07-09 Body Control (BCM), (under steering column)
YUKON XL 1500 11 Body Control (BCM); (under steering column)
AVALANCHE 1500 10 Body Control (BCM); (under steering column), ID 25835966
SIERRA 2500 PICKUP 07 Body Control (BCM); new style (smooth door skin), (under steering column)
ESCALADE 07-09 Body Control (BCM); (under steering column)
SIERRA 1500 PICKUP 07 Body Control (BCM); new style (smooth door skin), (under steering column)
SIERRA 1500 PICKUP 09 Body Control (BCM), (under steering column)
SIERRA DENALI 3500 11 Body Control (BCM); (under steering column)
SUBURBAN 2500 11 Body Control (BCM); (under steering column)
ESCALADE ESV 10 Body Control (BCM); (under steering column), ID 25835966
SIERRA 1500 PICKUP 08 Body Control (BCM); (under steering column)
SIERRA DENALI 08-10 Body Control (BCM); (under steering column)
SUBURBAN 1500 11 Body Control (BCM); (under steering column)
ESCALADE 10 Body Control (BCM); (under steering column), ID 25835966
SILVERADO 2500 PICKUP 07 Body Control (BCM); new style (smooth door skin), under steering column)
SILVERADO 2500 PICKUP 08 Body Control (BCM), (under steering column)
SILVERADO 3500 PICKUP 07 Body Control (BCM); new style (smooth door skin), (under steering column)
AVALANCHE 1500 11 Body Control (BCM)
TAHOE 11 Body Control (BCM); (under steering column)
Frequently Asked Questions
How does the cloning service work?
You send us your original BCM. We then extract the unique vehicle data—including the VIN and specific options for your truck—and flash it onto the replacement module. This makes the new part a perfect digital match for your vehicle, so it works right out of the box without dealer programming. Your original module is always returned to you.
Is this BCM a plug-and-play installation?
Yes, thanks to our cloning service, the module is electronically plug-and-play. However, as a security measure on GM vehicles, you may need to perform an ‘SDM Key Sync’ or ‘Brake Pedal Position Relearn’ with a capable scan tool if certain warning lights appear after installation.
Will this fix my airbag light?
A faulty BCM is a very common reason for an airbag light and DTC B1001. Replacing the module should correct the root cause, but you must perform the ‘Setup SDM Primary Key in BCM’ procedure with a scan tool to sync the modules and turn off the light.
Do I have to pay a core charge?
No. There is no core charge or deposit required for this part. We require your original module for the data cloning process and will return it to you along with the programmed replacement unit.