Is Your GM Truck or SUV Plagued by Electrical Gremlins?
If you’re dealing with a frustrating array of electrical issues in your Chevrolet Silverado, GMC Sierra, Tahoe, or Suburban, a failing Body Control Module (BCM) is the likely culprit. The BCM acts as the central command center for your vehicle’s body electronics, managing everything from your power windows and door locks to the HVAC system and security features. When it begins to fail, it can cause chaotic and unpredictable behavior that is often difficult to diagnose.
This genuine quality GM Body Control Module, interchangeable with part number 20939137, is the definitive solution. It arrives at your door fully pre-programmed to your vehicle’s specific VIN, ensuring a seamless, plug-and-play installation without requiring a costly trip to the dealership for programming. Restore order to your vehicle’s electronics and get back on the road with confidence.
From the Diagnostic Bay
We had a 2009 Silverado 1500 in the shop that was driving the owner crazy. The radio would turn off randomly, the driver’s side window wouldn’t roll down, and the anti-theft light would flash intermittently, sometimes preventing the truck from starting. The owner had already replaced the window switch and checked fuses, but the problems persisted. After hooking up our scanner, we saw a dozen communication codes pointing to a network failure. The root cause wasn’t a dozen separate issues; it was one failing BCM corrupting the entire system. Installing a VIN-programmed module like this one resolved every single issue in under 10 minutes.
Symptoms of a Failing 2007-2010 Sierra Denali BCM
- ✔ Intermittent or non-functional power windows, door locks, and interior/exterior lighting.
- ✔ HVAC system acting erratically, with blower motor issues or incorrect temperature control.
- ✔ Security system faults, causing no-start conditions or random alarm activation.
- ✔ Persistent Airbag warning light, often accompanied by DTC B1001.
- ✔ A flood of seemingly unrelated diagnostic trouble codes (DTCs) stored in the system.
- ✔ Wipers operating on their own or not working at all.
This module is the direct-fit, reliable replacement for a wide range of 2007-2013 General Motors trucks and SUVs. By providing your VIN at checkout, we ensure the module is flashed with the latest GM software and configured for your vehicle’s exact options. This critical step guarantees that all systems communicate correctly from the moment of installation. While the physical swap is simple—typically located under the driver’s side dash—be aware that some vehicles may require a post-install procedure. If the airbag light remains on, a ‘Setup SDM Primary Key in BCM’ procedure must be performed with a professional scan tool. In some cases, a Brake Pedal Position Relearn may also be necessary. These are standard procedures for ensuring all related safety systems are properly synchronized with the new BCM.
Frequently Asked Questions
Why is VIN programming so important for a BCM?
The BCM is tailored to your vehicle’s specific features (like power seats, sunroof, specific lighting, etc.). VIN programming loads this unique configuration onto the module, ensuring it communicates correctly with all other computers in your vehicle for seamless operation. A non-programmed module will cause more problems than it solves.
Is this part difficult to install myself?
The physical installation is straightforward for most DIY mechanics, typically taking less than 15 minutes. It’s located under the steering column. However, be prepared for potential post-install electronic procedures, like an airbag system sync, which may require a professional-grade scan tool.
Will this BCM fix my airbag warning light?
If the airbag light is caused by a communication error with a faulty BCM (like DTC B1001), this part will resolve the root cause. However, you will likely need to perform the ‘Setup SDM Primary Key in BCM’ procedure with a capable scan tool to clear the light after installation.
What makes this different from a used part from a salvage yard?
A used BCM is programmed to the donor vehicle’s VIN and options. Installing it in your truck will create a feature mismatch, leading to incorrect operation of various systems and potentially immobilizing your vehicle. Our modules are programmed specifically for your truck.
Do I need to return my old part?
No, there is no core charge for this part. You can keep your original module without any additional fees or hassle.