Restore Full Electrical Function to Your 2010 Chevrolet Avalanche 1500
If you’re battling bizarre electrical issues in your truck—from flickering dash lights and malfunctioning power windows to a security system that has a mind of its own—a failing Body Control Module (BCM) is often the hidden culprit. As the central command for your vehicle’s body electronics, its failure can cause a cascade of frustrating problems. This replacement BCM, part number 20921436, is the definitive solution to get your 2010 Avalanche 1500 running reliably again, without the excessive costs and scheduling hassles of a dealership visit.
From the Diagnostic Bay: The Case of the Haunted Truck
A customer brought in his 2010 Avalanche last month with a list of symptoms that sounded like the truck was possessed. The radio would turn on and off, the driver’s side window wouldn’t roll down, and the anti-theft light would flash randomly, sometimes preventing the truck from starting. He’d already replaced the battery and checked all the fuses. After connecting my scan tool, I saw a handful of communication error codes, primarily U0140 (Lost Communication with BCM). In my 20+ years of experience, a cluster of unrelated electrical faults almost always points back to a single network controller. We confirmed the BCM was failing internally. Instead of a costly dealer replacement and programming fee, we used this exact cloning service. The customer’s original data was transferred to the replacement unit, he installed it himself in under an hour, and all the ghostly electrical problems vanished. It’s a straightforward fix that saves hundreds.
Is Your Avalanche Showing These Symptoms?
A faulty BCM can manifest in numerous ways. If you’re experiencing any of the following, this module is likely the solution you need. Over the years, I’ve seen these issues countless times in the shop.
- ✔ Power windows, door locks, or mirrors operate intermittently or not at all.
- ✔ Interior or exterior lights flicker, stay on, or won’t turn on.
- ✔ The security system light is illuminated, and the vehicle may not start (Service Theft Deterrent System message).
- ✔ The radio or infotainment system behaves erratically.
- ✔ Your key fob stops working reliably.
- ✔ You have multiple communication Diagnostic Trouble Codes (DTCs) like U0140, U0155, or U0100.
A Straightforward Guide to BCM Installation
This module is designed for a direct-fit replacement. Our cloning service means you can skip the expensive trip to the dealer for programming. For a proficient DIYer, this is about a 30-60 minute job.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the BCM: In the 2010 Avalanche 1500, the BCM is typically located under the driver’s side of the dashboard, near the steering column. You may need to remove a lower dash panel for access.
- Disconnect the Old Module: Carefully unplug the electrical connectors from the original BCM. They have locking tabs that need to be depressed to release them. Note their orientation.
- Remove the Old BCM: Unbolt or unclip the old module from its mounting bracket.
- Install the New BCM: Mount your new, pre-programmed BCM in the same location and reconnect all the electrical connectors firmly until they click into place.
- Reconnect Power: Reattach the negative battery terminal.
- Test All Functions: Start the vehicle and test your power windows, locks, lights, radio, and other accessories to confirm the repair was successful.
Important Post-Installation Steps
Our cloning service handles the critical programming, but some vehicle systems may require a relearn procedure to sync with the new BCM. This is normal and ensures all safety systems function correctly.
- Airbag System Sync: If the airbag warning light is on after installation, a ‘Setup SDM Primary Key in BCM’ procedure is needed. This requires a professional-grade scan tool and ensures the airbag system is properly synchronized with the new BCM.
- Brake Pedal Position Relearn: On some models, a brake pedal position sensor relearn might be required to ensure your brake lights and traction control system are working as intended.
Disclaimer: Procedures can vary slightly by vehicle trim and options. Always consult a factory service manual or a qualified technician if you are unsure about any step.
Verified Vehicle Compatibility
This BCM is a direct replacement for part number 20921436 and is compatible with a wide range of GM vehicles. We program it specifically for your 2010 Chevrolet Avalanche 1500 using your VIN. It also fits the following models, but always verify your original part number matches one from our list:
Fits Models Such As: 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/ESV/EXT (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 1500 (10), Tahoe (10), Torrent (07-09), Traverse (09-12), Vue (08-10), Yukon/XL 1500 (10).
Note: Specific options or ID numbers may apply. Please check the original fitment data for details.
Frequently Asked Questions
What exactly is the ‘Cloning Service’?
What exactly is the ‘Cloning Service’?
The cloning service is how we make this a plug-and-play solution. We transfer the critical vehicle-specific data (like VIN, mileage, and key information) from your original, failing BCM directly onto the replacement unit. This ensures it communicates perfectly with your truck’s other modules, avoiding the need for expensive dealership programming.
Do I need to send my original BCM to you?
Yes. For the cloning service to work, we need your original module. After you place your order, we will provide instructions for sending it to us. We perform the service and ship both your original module and the ready-to-install replacement back to you.
Is this part guaranteed to fit my 2010 Avalanche?
Absolutely. As long as your vehicle is a 2010 Chevrolet Avalanche 1500 and your original BCM has one of the part numbers listed, this module is a guaranteed fit. The cloning process ensures it’s programmed specifically for your truck’s configuration.
What tools are required for installation?
Basic hand tools are all that’s typically needed: a socket set or nut driver to remove the lower dash panel and the module’s mounting bolts, and possibly a flathead screwdriver or trim removal tool to help release plastic clips. No special electronic tools are needed for the installation itself.
What if my airbag light comes on after I install it?
This is a possibility and is not a sign of a defective part. It simply means the BCM and the airbag system (SDM) need to be re-synchronized. This procedure, called ‘Setup SDM Primary Key in BCM,’ must be done with a bi-directional scan tool, which most professional repair shops have.