Restore Full Functionality to Your GM Truck with a Programmed BCM
Are you battling a storm of bizarre electrical issues in your truck? One minute the radio works, the next it’s dead. The power windows have a mind of their own, and a persistent airbag light is staring you down. These aren’t just annoyances; they’re classic signs of a failing Body Control Module (BCM). This module, part number 20939138, is the central nervous system for your vehicle’s body electronics. When it fails, it can cause chaos. This replacement BCM, prepared with our expert cloning service, is the definitive, no-dealership solution for your 2013 Silverado 3500 BCM and other compatible GM vehicles.
What is Our Cloning Service?
Forget about expensive dealership appointments and towing fees. Our unique cloning service makes this repair a true plug-and-play process. You send us your original BCM, and we professionally transfer all its critical data—including VIN, security information, and specific vehicle options—to this replacement unit. When you receive it back along with your original module, it will be a perfect electronic match for your truck. This ensures seamless integration without the need for any additional programming or relearn procedures at a shop, getting you back on the road faster.
A Technician’s Notebook: The Case of the Phantom Power Drain
A 2013 Silverado 3500 came into my bay with a complaint that stumped two other shops: a parasitic battery drain that would kill a new battery in two days. The owner had already replaced the alternator and battery twice. Diagnostics showed no obvious shorts. However, I noticed the interior lights would flicker faintly long after the doors were shut. Using a thermal camera, I saw the BCM was unusually warm. The internal circuits were failing, keeping certain relays partially energized and slowly draining the power. A replacement 2013 Silverado 3500 BCM, cloned from the original, solved the drain, the flickering lights, and a non-functional power lock issue the owner had forgotten to mention. It’s a perfect example of how one faulty module can create multiple, seemingly unrelated problems.
Is Your Silverado Showing These Symptoms? Common BCM Failure Signs
- ✔ Erratic or non-functional power windows, door locks, and interior/exterior lights.
- ✔ HVAC system problems, such as the blower motor not working or temperature controls failing.
- ✔ An active airbag warning light, often accompanied by Diagnostic Trouble Code (DTC) B1001.
- ✔ Vehicle security system malfunctions, including random alarm activation or no-start conditions.
- ✔ Unexplained battery drain or intermittent stalling caused by improper grounding signals.
- ✔ Communication errors with other modules on the CAN bus network.
A Straightforward Guide to BCM Installation
- ✔ Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- ✔ Locate the Module: The BCM is typically found under the driver’s side dashboard, near the steering column. You may need to remove a lower dash panel for access.
- ✔ Disconnect and Remove: Carefully unplug the electrical connectors from the old BCM. They have locking tabs that need to be depressed. Once disconnected, unbolt or unclip the module from its mounting bracket.
- ✔ Install the New BCM: Mount the new, cloned BCM in the same location and securely reconnect all electrical harnesses. Ensure they click into place.
- ✔ Post-Installation Checks: Reconnect the battery. Start the vehicle and test all body functions: lights, wipers, locks, windows, and HVAC. While our cloning service handles most programming, note the special procedures below.
- ✔ Handle Special Cases: If the airbag light remains on, a professional scan tool is needed to perform the ‘Setup SDM Primary Key in BCM’ procedure. Some models may also require a Brake Pedal Position relearn.
Verified Vehicle Compatibility
This module is a direct replacement for part number 20939138 and other interchangeable numbers on a wide range of GM trucks and SUVs. Please verify your part number before ordering. This part fits the following vehicles, among others:
ESCALADE & ESV/EXT 07-11
SIERRA 1500/2500/3500 & DENALI 07-13
SILVERADO 1500/2500/3500 07-13
SUBURBAN 1500/2500 07-11
TAHOE 07-11
YUKON & YUKON XL 1500/2500 07-11
Note: Some 2007 models require the new body style (smooth door skin). Some 2010-2013 models may have specific ID requirements like 25835966.
Frequently Asked Questions
What exactly is a ‘cloning service’?
Cloning is a process where we transfer the exact software, VIN, and security data from your original BCM to the replacement unit. This makes the new module a perfect electronic copy, eliminating the need for dealership programming and ensuring all your vehicle’s features work correctly upon installation.
Do I need to send my old BCM to you?
Yes, for the cloning service to be performed, you must send us your original module. We will return it to you along with your newly programmed replacement. There is no core charge, and you get to keep your original part.
What if the airbag light is still on after I install the new BCM?
This is a known GM security feature. If the airbag light persists (often with code B1001), the BCM needs to be synced with the airbag system’s Sensing and Diagnostic Module (SDM). This requires a professional scan tool to perform the ‘Setup SDM Primary Key in BCM’ function.
Is this a difficult part to replace for a DIYer?
The physical replacement is quite simple for most DIYers with basic tools. It’s typically located under the dash and held in by a few bolts or clips. The entire swap can often be done in under 30 minutes. Our cloning service removes the most difficult part: the computer programming.