Fix Your Truck’s Electrical Gremlins for Good
If you’re dealing with bizarre electrical issues in your 2007-2011 Chevrolet Avalanche 1500, you know the frustration. One day the radio works, the next it doesn’t. The power locks have a mind of their own, or the A/C blower motor quits unexpectedly. These aren’t random quirks; they’re classic signs of a failing Body Control Module (BCM). As the central command for your truck’s body electronics, a faulty BCM can cause chaos. This OEM-quality replacement, part number 20939138, arrives fully programmed to your vehicle’s VIN, offering a direct, reliable solution without a trip to the dealership.
Is Your Avalanche Showing These Signs of BCM Failure?
From my 20+ years in diagnostics, BCM failures often present as a cluster of unrelated problems. If you’re experiencing any of the following, it’s time to suspect the BCM:
- ✔ The security light is flashing, and the engine won’t start or stalls intermittently.
- ✔ Power windows, door locks, or interior lights work sporadically or not at all.
- ✔ The HVAC system is unresponsive, or the blower motor speed is erratic.
- ✔ You have an airbag warning light on the dash, often with a DTC like B1001 (Setup SDM Primary Key in BCM).
- ✔ Your scan tool shows communication errors or various body-related trouble codes.
- ✔ Headlights or taillights are acting strangely, staying on or not turning on.
Your Straightforward BCM Installation Guide
One of the best parts about this fix is the simplicity. For most DIYers, this is a 5-minute job. Here’s a quick rundown of the process:
- Safety First: Always disconnect the negative terminal from your truck’s battery before working on any electronics.
- Locate the BCM: On the Avalanche, it’s typically found under the driver’s side of the dashboard, near the steering column. You may need to remove a plastic knee bolster panel for access.
- Disconnect and Remove: The BCM is held in place by clips or small bolts and has several large electrical connectors. Carefully release the locking tabs on each connector and pull them straight out. Then, remove the old module.
- Install the New Module: Seat the new, pre-programmed BCM into the mounting bracket and firmly reconnect all electrical connectors. You’ll hear a click as they lock into place.
- Reconnect and Test: Reconnect the battery terminal. Start the vehicle and test all functions: windows, locks, lights, wipers, and HVAC to confirm the repair was successful.
Why Choose Our 2007-2011 Avalanche 1500 BCM?
This isn’t just a replacement part; it’s a complete solution. By pre-programming the module to your specific VIN, we eliminate the need for expensive scan tools or dealership intervention. It restores the complex communication network between your truck’s safety, security, and convenience systems. Built to strict OEM standards and backed by a one-year warranty, this module ensures long-term reliability for your workhorse or daily driver. It is a direct replacement for part numbers 25844480, 20939138, 25971917, and others listed below.
Verified Vehicle Compatibility
This Body Control Module is a confirmed fit for the following vehicles, among others. Please verify your part number before ordering.
Chevrolet:
2007-2011 Avalanche 1500
2007-2011 Silverado 1500/2500/3500
2007-2011 Suburban 1500/2500
2007-2011 Tahoe
GMC:
2007-2011 Sierra 1500/2500/3500
2007-2011 Sierra Denali
2007-2011 Yukon & Yukon XL
Cadillac:
2007-2011 Escalade, ESV, & EXT
Frequently Asked Questions
Is this BCM really plug-and-play?
Yes. We program the module with your vehicle’s VIN before shipping. This ensures it communicates correctly with your truck’s other systems right out of the box, with no need for a trip to the dealer.
What if my airbag light stays on after installation?
This is a known GM security feature. If the airbag light persists (often with code B1001), a procedure called ‘Setup SDM Primary Key in BCM’ is required. This must be done with a bi-directional scan tool but is a simple function for any professional mechanic.
Do I need to send my old BCM back?
No. There is absolutely no core charge for this part. You can keep your old module or dispose of it responsibly.
What tools do I need for the installation?
For most installations, you’ll only need basic hand tools like a socket or a screwdriver to remove the lower dash panel. The BCM connectors have release tabs that don’t require special tools.
Will this fix my intermittent stalling issue?
It can. The BCM is tied into the vehicle’s security and anti-theft systems. If it fails, it can incorrectly signal the powertrain control module (PCM) to shut down the engine, causing a no-start or stalling condition.