Restore Full Electrical Function to Your GM Vehicle
Are you battling bizarre electrical issues in your Chevy Express, GMC Savana, or other compatible GM vehicle? Flickering lights, malfunctioning power windows and locks, a security system that acts on its own, or even a vehicle that refuses to start can all point to a single culprit: 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 cause a cascade of frustrating and seemingly unrelated problems. This replacement BCM, part number 20921436, is the direct solution to restore order and reliability to your vehicle’s essential functions.
Why Choose Our Programmed Express 2500 Body Control Module?
Forget expensive dealership visits and the hassle of programming a new module. We take care of the hard part for you. Simply provide your vehicle’s VIN during checkout, and our experts will program this BCM with the latest GM software specific to your vehicle. This ensures a seamless installation process, getting you back on the road or back to work with minimal downtime. This is a true plug-and-play solution designed for both professional technicians and savvy DIYers.
From the Diagnostic Bay
We had a 2011 Express 2500 work van come in that was driving the owner crazy. The radio would turn on and off, the dome light would stay on, and occasionally the van wouldn’t start, but only on humid days. We checked all the usual suspects—battery, alternator, grounds—and found nothing. After pulling the BCM from under the dash, we saw the tell-tale signs of water intrusion. A small leak from the windshield cowl had been dripping onto the module, causing corrosion and intermittent short circuits. Installing a pre-programmed BCM like this one solved every single issue instantly. It’s a common failure point, and a programmed replacement is the fastest, most reliable fix.
Common Symptoms of a Failing BCM
- ✔ Erratic or non-functional interior and exterior lights (headlights, taillights, dome lights).
- ✔ Power windows, door locks, or mirrors not working correctly or at all.
- ✔ Vehicle security system engaging randomly or preventing the engine from starting.
- ✔ Horn sounding unexpectedly or not working when pressed.
- ✔ Wipers operating intermittently or not parking in the correct position.
- ✔ Warning lights on the dashboard, such as the airbag or security light.
- ✔ Complete no-start condition where the starter does not engage.
Installation and Post-Install Notes
While this module is delivered programmed for your vehicle, some GM platforms may require additional vehicle-specific relearn procedures after installation. These are simple steps that sync the new module with other systems in your vehicle.
- Airbag System Sync: If your airbag warning light is illuminated after installation, a professional scan tool is needed to perform the ‘Setup SDM Primary Key in BCM’ procedure. This syncs the new BCM with the airbag system.
- Brake Pedal Position Relearn: On some models, a brake pedal position sensor recalibration might be necessary to ensure correct brake light and traction control operation.
Always consult a factory service manual or a qualified technician for guidance specific to your vehicle.
This is a direct replacement for the following part numbers:
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 does a Body Control Module do?
The BCM acts as a central computer for your vehicle’s body electronics. It controls non-engine related functions like power windows, locks, lights, wipers, security systems, and more.
Is this BCM truly plug-and-play?
Yes, it comes programmed to the VIN you provide, so it does not require a trip to the dealership for initial programming. However, as with any BCM replacement, some vehicles may require minor ‘relearn’ procedures for systems like the airbag or brake pedal position sensor after installation.
How do I provide my VIN?
After you complete your purchase, you will need to send us your 17-digit Vehicle Identification Number (VIN). We cannot program and ship your module without it.
What if my airbag light is on after installing the new BCM?
This is a known possibility. It means the new BCM needs to be synced with the airbag’s Supplemental Inflatable Restraint (SIR) module. A procedure called ‘Setup SDM Primary Key in BCM’ must be performed with a professional-grade scan tool to resolve this.
Do I need to return my old BCM?
No, there is no core charge for this part. You can keep your original module.
Will this Express 2500 Body Control Module fit other vehicles?
Yes, this BCM fits a wide range of GM vehicles including the GMC Savana, Chevy Tahoe, Suburban, Impala, Acadia, and many more. Please check the detailed fitment list on this page to confirm compatibility with your specific year, make, and model.