Are you experiencing a cascade of frustrating electrical problems in your GM truck or SUV? Intermittent wipers, flickering lights, unresponsive power windows, or a malfunctioning security system are all classic signs of a failing Body Control Module (BCM). The BCM is the central nervous system for your vehicle’s body electronics, and when it fails, it can make your truck feel possessed. This genuine GM Body Control Module, compatible with part number 20939138, is the definitive solution to restore order and full functionality to your vehicle.
From the Diagnostic Bay
We had a 2013 GMC Sierra Denali 3500 roll into the shop that was a complete electrical nightmare. The owner said the radio would randomly turn off, the driver’s side power window wouldn’t work, and the airbag light was on. He’d been to two other shops that couldn’t pinpoint the issue. After scanning the vehicle, we found a slew of communication codes all pointing back to a faulty BCM. Instead of a costly, time-consuming repair at the dealership, we installed one of our VIN-programmed modules. In under 10 minutes, the truck was back to normal. The owner was thrilled to have his premium truck working correctly again without the dealership hassle.
Common Symptoms of a Failing BCM
- ✔ Unresponsive or erratic power windows, door locks, and interior/exterior lights.
- ✔ HVAC system malfunctions, such as the blower motor not working or temperature controls failing.
- ✔ An illuminated airbag warning light, often accompanied by DTC B1001.
- ✔ Security system errors, including random alarm activation or no-start conditions.
- ✔ Erratic behavior from dashboard gauges or warning messages.
- ✔ Communication errors with other vehicle modules, leading to a variety of diagnostic trouble codes (DTCs).
The Right Fix for Your 2013 Sierra Denali BCM
Don’t settle for a temporary fix or a complicated dealership visit. This module is pre-programmed to your vehicle’s specific Vehicle Identification Number (VIN) before it ships. This critical step ensures that the module communicates flawlessly with your truck’s existing systems right out of the box. There is no need for expensive trips to the dealer for programming. It’s a true plug-and-play solution designed to get you back on the road quickly and confidently. Built to strict OEM standards, this BCM guarantees the reliability and durability your hardworking truck demands.
Installation and Post-Install Procedures
Physically installing the BCM is straightforward. It is typically located under the driver’s side dashboard near the steering column and can be swapped out in minutes. However, please be aware of potential post-installation steps:
- Airbag System Sync: If the airbag warning light is illuminated 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 module is a direct replacement for a wide range of part numbers, including 25844480, 25835966, 15943678, 20939137, and 22860591. With no core charge, you can keep your old part without any hassle.
Frequently Asked Questions
What does a Body Control Module (BCM) do?
The BCM acts as the main computer for your vehicle’s body electronics. It controls non-engine related functions like power windows, locks, lights, wipers, the security system, and HVAC controls.
Is this module truly plug-and-play?
Yes, because we program it to your vehicle’s VIN before shipping, it is ready for installation without needing any additional dealership programming for standard functions. Some specific procedures, like an airbag system sync, may be required depending on your vehicle’s state.
What if my airbag light is on after installing the new BCM?
This is a common security feature. You will need a professional scan tool with the appropriate capabilities to perform the ‘Setup SDM Primary Key in BCM’ function to sync the modules and turn off the light.
Do I need to send my old part back?
No, there is absolutely no core charge for this part. You can keep your original module without any extra fees or hassle.
How can I be sure this fits my truck?
This module fits a wide range of 2007-2013 GM trucks and SUVs, including the Sierra, Silverado, Tahoe, and Escalade. Please verify your part number against the provided interchange list or contact us with your VIN to confirm compatibility.