Restore Full Functionality to Your GM Vehicle
Are you battling a storm of bizarre electrical issues in your Cadillac Escalade, Chevy Silverado, or GMC Sierra? One minute the power windows work, the next they don’t. The A/C blower motor has a mind of its own, and a persistent airbag light is staring you down. As a technician with over two decades of experience, I’ve seen this exact scenario hundreds of time. The culprit is almost always a failing Body Control Module (BCM), the electronic nerve center of your vehicle’s comfort and security features.
This isn’t just an inconvenience; it’s a breakdown in your vehicle’s core systems. Our replacement Body Control Module, equivalent to part number 20939137, is the definitive solution. We take the guesswork and dealership hassle out of the equation by pre-programming it to your vehicle’s specific VIN. This ensures that when it arrives, it’s ready for a true plug-and-play installation, immediately restoring the systems you rely on every day.
A Technician’s Notebook: The Grounding Gremlin
A 2009 Silverado 2500 came into my bay with a classic case of BCM failure—intermittent wipers, flickering dash lights, and a no-start condition that left the owner stranded. He had already replaced the battery and alternator. After plugging in the new, programmed BCM, most issues vanished, but the truck still occasionally hesitated to start. A quick voltage drop test revealed the root cause of the original BCM’s demise: a corroded ground strap under the driver’s side dash. We cleaned the contact point, and the truck has run flawlessly since. Moral of the story: When replacing a BCM, always inspect the main ground connections. A poor ground can fry a new module just as easily as it killed the old one.
Is Your GM Truck Exhibiting These Electrical Symptoms?
A faulty BCM can cause a cascade of seemingly unrelated problems. If your vehicle is showing these signs, a BCM replacement is the likely fix.
- ✔ Power windows, door locks, or mirrors operating erratically or not at all.
- ✔ HVAC system issues, such as the blower fan not working or temperature controls being unresponsive.
- ✔ An active airbag warning light on the dashboard, often accompanied by diagnostic trouble code (DTC) B1001.
- ✔ The security system preventing the engine from starting or causing random stalling.
- ✔ Interior dome lights or exterior lamps failing to turn on or off correctly.
- ✔ Wipers getting stuck or activating on their own.
Your 5-Minute Path to a Full Restoration
Forget spending hours at a dealership. This module is designed for a straightforward DIY installation right in your driveway.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before beginning any electrical work.
- Locate the BCM: On most compatible GM trucks and SUVs, the BCM is located under the driver’s side dashboard, near the steering column.
- Swap the Module: Carefully unplug the electrical connectors from the old BCM. Remove any retaining clips or bolts, and take out the old module. Position the new module and securely re-attach the electrical connectors and mounting hardware.
- Reconnect and Test: Reconnect the negative battery terminal. Start the vehicle and test all body functions—windows, locks, lights, wipers, and HVAC—to confirm the repair.
- Post-Installation Checks: In some cases, an airbag light may remain on. This requires a professional scan tool to perform the ‘Setup SDM Primary Key in BCM’ function. Similarly, a ‘Brake Pedal Position Relearn’ might be needed. These are simple procedures for any qualified shop.
Verified Compatibility for Your GM Vehicle
This module is a direct replacement for part number 20939137 and other interchangeable numbers, ensuring a perfect fit for a wide range of popular GM models. Please verify your vehicle below.
Fits: 2007-2011 Cadillac Escalade ESV, Escalade, Escalade EXT; 2007-2013 Chevrolet Avalanche, Silverado 1500/2500/3500, Suburban, Tahoe; and 2007-2013 GMC Sierra 1500/2500/3500, Sierra Denali, Yukon, Yukon XL. Please match your part number or contact us with your VIN to confirm fitment.
Frequently Asked Questions
Frequently Asked Questions
Do I need to have this BCM programmed by the dealer?
No. We pre-program the module to your vehicle’s VIN before shipping. This makes the installation plug-and-play, saving you the time and expense of a dealership visit.