Restore Full Functionality to Your GM Vehicle
Are you battling bizarre electrical issues in your 2009-2012 Chevrolet Traverse? Intermittent wipers, flickering lights, power windows with a mind of their own, or a security light that won’t turn off are 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 create a cascade of frustrating and unpredictable problems. This isn’t just an annoyance; it can be a safety concern when essential systems like lighting and door locks become unreliable.
This replacement BCM, part number 20921435, is the definitive solution. We take the guesswork and high cost out of the repair by programming the module specifically to your vehicle’s VIN before it ships. This means it arrives at your door ready for installation, loaded with the latest GM software updates to ensure optimal performance and compatibility. You get a reliable, direct-fit part without the need for an expensive trip to the dealership for programming.
Case Study: The Ghost in the Acadia
A customer brought in a 2011 GMC Acadia (which uses the same BCM as the Traverse) with a laundry list of complaints: the radio would turn off randomly, the liftgate wouldn’t open, and the driver’s side power window only worked occasionally. They had already replaced the window switch and checked fuses. My initial scan showed multiple communication loss codes (U-codes) with various modules. This pointed directly to the BCM. After confirming power and ground to the module were solid, we installed one of our pre-programmed BCMs. In under an hour, every single one of the ghost-like electrical problems was gone. The customer saved hundreds compared to the dealer quote and drove away with a perfectly functioning vehicle.
Common Signs of a Failing BCM in Your Traverse
If you’re experiencing any of the following, a faulty BCM is the likely culprit. Over my 20+ years in diagnostics, these are the symptoms I see most often with this specific module failure.
- ✔ Erratic or non-functional interior and exterior lights.
- ✔ Power windows, door locks, or mirrors behaving unpredictably.
- ✔ The security system engaging randomly or the security light staying on.
- ✔ Wipers turning on by themselves or not working at all.
- ✔ Instrument cluster warning lights appearing without cause (e.g., ABS, Airbag).
- ✔ Diagnostic trouble codes related to communication errors, such as U0140 (Lost Communication With Body Control Module).
- ✔ Remote keyless entry failure.
Your Straightforward BCM Installation Guide
Installing your new BCM is a manageable task for a confident DIYer. For the 2009-2012 Traverse, the BCM is typically located on the left (driver’s) side of the dash, often behind the lower trim panel.
- Safety First: Disconnect the negative terminal from your vehicle’s battery and wait at least 10-15 minutes to allow all systems to power down completely.
- Access the Module: Remove the necessary lower dash panels and trim to gain clear access to the old BCM. It’s a black box with several large multi-pin electrical connectors.
- Disconnect and Remove: Carefully unplug all electrical connectors from the old BCM. Most have a locking tab that needs to be depressed or a lever that needs to be swung over. Once disconnected, unbolt or unclip the module from its mounting bracket.
- Install the New BCM: Mount your new, pre-programmed BCM in the same location and securely reconnect all the electrical connectors. Ensure they click into place.
- Final Steps: Reassemble the dash panels and reconnect the negative battery terminal. Start the vehicle and test all functions: lights, windows, locks, wipers, etc.
- Post-Installation Checks: As noted in our policies, some vehicles may require a post-installation procedure like a brake pedal position relearn or an airbag system sync if a warning light appears.
Important Post-Installation Information
This module is designed to be as close to plug-and-play as possible. However, due to the complexity of modern vehicle systems, a couple of additional steps may be needed.
- ✔ No Core Charge: You are not required to return your old BCM. This saves you time and the hassle of a core return.
- ✔ Airbag System Sync: If the airbag light is on after installation, a shop with a capable diagnostic tool will need to perform the “Setup SDM Primary Key in BCM” procedure. This is a simple sync process.
- ✔ Brake Pedal Position Relearn: On some models, a brake pedal position sensor relearn may be required to ensure brake lights and traction control function correctly.
Disclaimer: Vehicle systems vary. Always refer to a factory service manual or consult with a qualified technician if you are unsure about any step.
Verified Vehicle Compatibility List
This BCM is a direct replacement for a wide range of GM vehicles. Please match your original part number to the list below or confirm your vehicle is listed. This unit replaces 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.
Fits models including: Acadia (07-12), Avalanche 1500 (10), Caprice (11-13), Captiva Sport (12), CTS (08-13), DTS (06-11), Enclave (08-12), Equinox (07-09), Escalade (10), Express/Savana Vans (08-12), G8 (08-09), Hummer H2 (08-09), Impala (06-13), Lucerne (06-11), Monte Carlo (06-07), Outlook (07-10), SRX (07-09), STS (10), Suburban (10), Tahoe (10), Torrent (07-09), Traverse (09-12), Vue (08-10), Yukon (10).
Do I need to get this BCM programmed by a dealer?
Do I need to get this BCM programmed by a dealer?
No. We handle the programming for you before we ship the part. Simply provide your vehicle’s VIN at checkout, and we will flash the module with the latest GM software specific to your car. It arrives ready to install.
What is a VIN and where do I find it?
The VIN (Vehicle Identification Number) is a unique 17-digit code for your vehicle. You can find it on your driver’s side dashboard (visible through the windshield), on the driver’s side door jamb sticker, or on your vehicle’s registration and insurance documents.
Is there a core charge for this part?
No, there is no core charge. You can keep your old module, which saves you the cost and hassle of shipping it back.
What if my airbag light comes on after installation?
This can occasionally happen. It means the new BCM needs to be electronically ‘introduced’ to the airbag system’s computer (SDM). A repair shop with a professional scan tool can perform the ‘Setup SDM Primary Key in BCM’ procedure to resolve this.
Where is the BCM located on my 2011 Traverse?
On the 2009-2012 Chevrolet Traverse, the BCM is typically located on the driver’s side of the dashboard, behind the lower trim panel near the steering column.