Fix Annoying Electrical Problems in Your GM Truck or SUV
Is your GMC Sierra, Chevrolet Silverado, or Tahoe plagued by strange electrical issues? Intermittent wipers, flickering lights, a non-responsive HVAC system, or power windows with a mind of their own are all classic signs of a failing Body Control Module (BCM). The BCM is the central command center for your vehicle’s body electronics, and when it starts to fail, it can cause a cascade of frustrating and difficult-to-diagnose problems. This genuine quality GM Body Control Module, part number 20939137, is the definitive solution to restore your vehicle’s electronic systems to perfect working order.
From the Diagnostic Bay
We had a 2010 Silverado 2500 come into the shop with a laundry list of complaints. The owner said the radio would cut out, the driver’s side power lock wouldn’t work, and the A/C blower was completely dead. He’d already replaced the blower motor resistor with no luck. After hooking up the scanner, we saw a dozen communication codes pointing to the BCM. Instead of spending hours chasing wires, we installed one of our VIN-programmed BCMs. In less than 15 minutes, every single issue was resolved. It’s a reminder that sometimes the most complex-seeming electrical gremlins have a simple, central cause.
Symptoms of a Failing 2007-2011 Sierra 2500 BCM
If you’re experiencing any of the following issues, a faulty BCM is the most likely culprit. Replacing it can save you hours of diagnostic time and hundreds of dollars in labor costs.
- ✔ Power windows, door locks, or mirrors operating erratically or not at all.
- ✔ Interior or exterior lights flickering, staying on, or failing to turn on.
- ✔ HVAC controls are unresponsive, or the blower motor works intermittently.
- ✔ The vehicle’s security system malfunctions, causing false alarms or starting issues.
- ✔ An airbag warning light is illuminated on the dash, often with DTC B1001.
- ✔ Unexplained battery drain when the vehicle is turned off.
- ✔ Communication errors with other modules when read by a diagnostic scanner.
The Plug-and-Play Advantage: Pre-Programmed for Your VIN
Don’t waste time and money on a trip to the dealership. This Body Control Module arrives at your door fully programmed to your vehicle’s specific Vehicle Identification Number (VIN). We load the latest GM software updates, ensuring complete compatibility and optimal performance right out of the box. This critical step means you can install it yourself in minutes and avoid the expensive programming fees and scheduling hassles associated with a dealership visit. It’s a true plug-and-play repair.
Installation and Post-Install Procedures
The BCM is typically located under the driver’s side dashboard, near the steering column. Installation is a straightforward process of disconnecting the battery, removing a few trim panels, and swapping the electrical connectors from the old module to the new one. While the module is pre-programmed, some vehicles may require a simple relearn procedure after installation.
- Airbag System Sync: If the airbag warning light is on after installation, a ‘Setup SDM Primary Key in BCM’ procedure must be performed using a professional-grade scan tool. This syncs the new BCM with the airbag system.
- Brake Pedal Position Relearn: On some models, a brake pedal position sensor recalibration may be needed 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, 15263363, 15943678, 25790508, 25835965, 20939138, and 22860591. Verify your part number to ensure a perfect match.
Frequently Asked Questions
What does the Body Control Module (BCM) do?
The BCM is a computer that manages and controls many of your vehicle’s non-engine related electronic functions. This includes power windows, door locks, lighting, wipers, the security system, and the climate control system.
Why is VIN programming so important for a BCM?
VIN programming loads your vehicle’s specific software, options, and security information onto the module. Without it, the BCM will not communicate correctly with other computers in your vehicle, leading to system malfunctions or a no-start condition. Our pre-programming makes it a plug-and-play part.
Is this module difficult to install?
For most DIY mechanics, the physical installation is simple and takes under 30 minutes. It’s typically located under the dash and involves swapping a few electrical connectors. However, be aware that post-install procedures like an airbag sync may require a professional scan tool.
What happens if my airbag light is on after I install this?
This is a common occurrence. It means the new BCM needs to be electronically introduced to the vehicle’s Sensing and Diagnostic Module (SDM). A mechanic with a high-level scan tool can perform the ‘Setup SDM Primary Key in BCM’ function to resolve this in a few minutes.
Do I need to send my old part back?
No. This module is sold with no core charge. You can keep your original part without any additional fees or hassle.