Restore Full Electrical Function to Your GM Truck or SUV
Are you battling bizarre electrical issues in your Chevrolet Silverado, GMC Sierra, or Tahoe? Flickering lights, unresponsive power windows, a malfunctioning security system, or a persistent airbag light are common signs of a failing Body Control Module (BCM). The BCM is the central command center for your vehicle’s body electronics, and when it fails, it can cause a cascade of frustrating problems. This OEM-quality GM Body Control Module, interchangeable with part number 20939137, is the definitive solution, arriving pre-programmed to your vehicle’s VIN for a hassle-free, plug-and-play installation.
We had a 2013 Sierra Denali 2500 in the shop that the owner described as ‘haunted.’ The radio would change stations on its own, the dome light would stay on, and the power locks worked intermittently. After hours of chasing wires and checking grounds, we traced it all back to a faulty BCM. Swapping in a VIN-programmed module like this one solved every single issue in under 10 minutes. It’s often the simplest solution to the most complex-seeming electrical gremlins.
Symptoms of a Failing GMC Sierra BCM
A failing BCM can manifest in numerous ways. If you’re experiencing any of the following, it’s time to consider a replacement:
- ✔ Unresponsive or erratic power windows, door locks, or interior/exterior lights.
- ✔ HVAC system failures, such as a blower motor that won’t turn on or stays stuck on one speed.
- ✔ An illuminated airbag warning light, often accompanied by Diagnostic Trouble Code (DTC) B1001.
- ✔ Security system malfunctions, including random alarm activation or no-start conditions.
- ✔ Intermittent stalling, engine misfires, or other performance issues linked to poor electrical grounding managed by the BCM.
- ✔ A variety of communication-related DTCs stored in the vehicle’s computer system.
Plug-and-Play Solution with VIN Programming
The biggest hurdle in replacing a BCM is the need for expensive programming at a dealership. We eliminate that step entirely. Simply provide your vehicle’s VIN during checkout, and we will program the module with the latest GM software specific to your truck. This ensures that all systems communicate correctly right out of the box, restoring factory performance without any additional calibration. This module is a direct replacement for a wide range of part numbers, including 25844480, 25835966, 15943678, 20939137, 22860591, and more.
Installation and Post-Install Considerations
Installation is straightforward for most DIY mechanics. The BCM is typically located under the driver’s side dashboard, near the steering column. In most cases, you simply disconnect the negative battery terminal, unplug the electrical connectors from the old module, remove it, and install the new one. However, please be aware of a few potential post-installation steps:
- Airbag System Sync: If the airbag warning light remains on after installation, a procedure called ‘Setup SDM Primary Key in BCM’ must be performed using a professional-grade scan tool. This syncs the new BCM with the airbag system.
- Brake Pedal Position Relearn: Some models may require a brake pedal position sensor relearn to ensure proper brake light and traction control operation.
This part requires no core return, so you can keep your old module without the hassle of shipping it back. Restore the reliability and functionality of your vehicle with this dependable, pre-programmed Body Control Module.
Frequently Asked Questions
Do I need to have this BCM programmed by a dealer?
No. This Body Control Module comes pre-programmed to your vehicle’s specific VIN. It is ready for installation right out of the box, saving you a trip to the dealership.
Where is the BCM located on my 2013 Sierra Denali 2500?
The BCM is located under the driver’s side dashboard, typically to the left of the steering column. Installation usually takes only a few minutes.
What happens if my airbag light is on after I install the new BCM?
If the airbag light is on, it means the new BCM needs to be electronically synced with the vehicle’s Sensing and Diagnostic Module (SDM). This requires a professional scan tool to perform the ‘Setup SDM Primary Key in BCM’ function.
My original part number is 25844480. Will this part 20939137 work?
Yes. This module is a direct replacement and is interchangeable with a long list of part numbers, including 25844480, 25835966, 25971916, and 20939137. It covers a wide range of 2007-2013 GM trucks and SUVs.
Is there a core charge for this part?
No, there is no core charge. You are not required to return your old, faulty module, making the replacement process simpler and more convenient.