Restore Full Electronic Functionality to Your GM Vehicle
Is your Chevrolet Express, GMC Savana, or other compatible GM vehicle plagued by mysterious electrical problems? Flickering lights, unresponsive power windows, a security system that acts on its own, or a persistent battery drain can often be traced back to a single component: a failing Body Control Module (BCM). The BCM acts as the central command center for your vehicle’s body electronics, and when it malfunctions, it can create a cascade of frustrating and difficult-to-diagnose issues. This replacement Body Control Module, part number 20935349, is the definitive solution to restore your vehicle’s systems to perfect working order.
We had a 2011 Savana 2500 work van come into the shop with a classic parasitic battery drain. The owner had already replaced the battery twice and the alternator once, but every few days, the van would be dead. Standard diagnostic tests were inconclusive. After isolating circuits, we noticed the BCM wasn’t allowing the vehicle’s data network to go to ‘sleep’. It was keeping other modules awake all night, slowly draining the battery. Installing a VIN-programmed BCM like this one solved the problem instantly. It’s a reminder that a BCM issue isn’t always about what doesn’t work, but sometimes about what won’t turn off.
Common Symptoms of a Failing BCM
- ✔ Erratic or non-functional interior and exterior lights (headlights, dome lights, dash lights).
- ✔ Power windows, door locks, or mirrors working intermittently or not at all.
- ✔ Malfunctioning security system, including random alarm activation or key fob issues.
- ✔ Unexplained parasitic battery drain that kills your battery overnight.
- ✔ False warning lights appearing on the instrument cluster (e.g., ‘Service Theft System’).
- ✔ Horn honking unexpectedly or not working when pressed.
- ✔ Wipers behaving erratically, either not turning on or not turning off.
The Direct-Fit Express 3500 Body Control Module Solution
Don’t let a faulty module keep your vehicle off the road or force you into an expensive visit to the dealership. We take the hassle out of the repair process. When you purchase this Express 3500 Body Control Module, you’re not just getting a part; you’re getting a complete, ready-to-install solution. We use your vehicle’s VIN to program the module with the latest GM software updates specifically for your make and model. This ensures seamless communication with your vehicle’s other electronic systems and restores all original functionality without the need for additional dealer programming.
Installation and Post-Install Considerations
While the physical installation is straightforward for a technician or experienced DIYer, some vehicles may require simple electronic relearn procedures after the new BCM is connected. These are not complex programming steps but rather synchronization processes that can be performed with a capable diagnostic scan tool.
- Airbag System Sync: If your airbag warning light is illuminated after installation, a ‘Setup SDM Primary Key in BCM’ procedure is necessary to sync the new BCM with the airbag system.
- Brake Pedal Position Relearn: Some models may require a brake pedal position sensor recalibration to ensure proper brake light and traction control operation.
Always consult a factory service manual for your specific vehicle for detailed instructions.
Broad Compatibility Across the GM Lineup
This BCM is a direct replacement for a wide array of original equipment part numbers, ensuring a perfect fit and function for many vehicles beyond the Express van. If your original module has any of the following part numbers, this unit is the correct replacement for you:
10382479, 15093910, 15276271, 15299986, 15819552, 15828601, 15837419, 15872388, 15872421, 15880684, 15921352, 15921353, 15948438, 15948439, 20815898, 20839063, 20864767, 20864768, 20921435, 20921436, 20935349, 22860591, 25826124, 25826125, 25847588, 25847589, 25892622, 25910474, 25934762, 25934763, 95151084.
Frequently Asked Questions
What exactly does the Body Control Module do?
The BCM is a computer that manages and controls many of your vehicle’s non-engine related electronic functions. This includes power windows, power locks, the security system, interior and exterior lighting, wipers, and more. It acts as a hub, receiving input from switches and sending commands to the various accessories.
Is this BCM truly plug-and-play?
Yes, for the vast majority of vehicles. Because we program the module to your specific VIN before shipping, it arrives ready to be installed without requiring a trip to the dealer for programming. In some cases, minor relearn procedures, like for the airbag or brake pedal sensor, may be needed with a scan tool.
How do I provide my VIN for programming?
After you complete your purchase, we will contact you for your vehicle’s 17-digit Vehicle Identification Number (VIN). We cannot ship your order until we receive the VIN, as this information is essential for programming the module correctly for your vehicle’s specific options.
What happens if my airbag light comes on after installation?
This is a common security feature. The new BCM needs to be electronically ‘introduced’ to the airbag’s Sensing and Diagnostic Module (SDM). A technician with a professional scan tool will need to perform the ‘Setup SDM Primary Key in BCM’ procedure to sync the modules and turn off the light.
Do I need to return my old BCM?
No. This product has no core charge. You can keep your original module, which can be helpful for double-checking part numbers or for any other diagnostic purposes.
Can a bad BCM cause a dead battery?
Absolutely. One of the most common BCM failure modes is an internal fault that prevents it from going into a low-power ‘sleep’ mode. This, in turn, can keep other modules on the vehicle’s data network awake, causing a slow but steady drain on the battery known as a parasitic draw.