End the Electrical Gremlins in Your GM Vehicle
If you’re dealing with bizarre electrical issues in your 2007-2012 GMC Acadia—like flickering lights, malfunctioning power windows, or a car that refuses to start—a failing Body Control Module (BCM) is often the culprit. As a technician with over two decades of experience, I’ve seen how a bad BCM can turn a reliable vehicle into a source of constant frustration. It’s the central hub for your car’s body electronics, and when it fails, chaos ensues. This replacement BCM, part number 20935349, is the definitive solution to restore order and get your vehicle functioning correctly again.
A Technician’s Notebook: The Case of the Haunted Acadia
I remember an ’09 Acadia that came into the shop with symptoms the owner described as ‘haunted.’ The dome lights would randomly turn on while driving, the radio would shut off, and occasionally, the vehicle wouldn’t crank. The owner had already replaced the battery and checked the alternator. After hooking up my scanner, I saw multiple U-codes (communication loss) pointing to an intermittent BCM. Instead of a costly and time-consuming dealer replacement, we used a cloned module like this one. We transferred the data from his failing BCM, installed the new unit, and the ‘haunting’ was over. The customer saved hundreds and got his vehicle back the same day.
The Power of Our Cloning Service
Forget about expensive dealership programming and towing fees. Our unique cloning service makes this repair straightforward. You simply send us your original BCM. We then extract the vehicle-specific data—including key information, security settings, and learned parameters—and transfer it directly to this replacement module. We also ensure the module has the latest stable software from GM before the cloning process. The result? You receive a BCM that is truly plug-and-play. It will integrate seamlessly with your vehicle’s systems, just like the original did when it was new.
Is Your Vehicle Showing These Symptoms?
- ✔ Erratic or non-functional interior and exterior lights
- ✔ Power windows, door locks, or mirrors working intermittently or not at all
- ✔ The security system light stays on or flashes, preventing the engine from starting
- ✔ “Service Theft Deterrent System” message on the dash
- ✔ Complete no-crank, no-start condition with a good battery
- ✔ Diagnostic trouble codes (DTCs) such as U0140, U0155, or other communication errors
- ✔ Wipers or radio turning on and off by themselves
A Straightforward Guide to Installation
- ✔ Safety First: Always disconnect the negative terminal from your vehicle’s battery before beginning any electrical work.
- ✔ Locate the BCM: In the 2007-2012 Acadia, the BCM is typically located on the left-hand (driver’s) side of the dashboard, often behind the lower dash panel near the steering column.
- ✔ Disconnect and Remove: Carefully unplug the electrical connectors from the module. They have locking tabs that need to be depressed. Once disconnected, remove any bolts or clips holding the BCM in place and take it out.
- ✔ Install the New Module: Seat the new, cloned BCM in the mounting bracket and secure it. Reconnect all electrical connectors, ensuring they click firmly into place.
- ✔ Reconnect and Test: Reconnect the negative battery terminal. Turn the key to the ‘On’ position and test all body functions—lights, locks, windows, wipers, and radio—to confirm proper operation before starting the engine.
Important Post-Installation Steps
While our cloning service makes this a plug-and-play repair, some GM vehicles may require a simple relearn procedure to ensure all systems are communicating perfectly. These do not always occur but are important to be aware of:
- Airbag System Sync: If your airbag warning light is on 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 may be necessary for proper brake light and traction control operation.
Disclaimer: Always consult a factory service manual or a certified technician if you are unsure about any part of the installation or post-installation process.
Verified Vehicle Compatibility
This BCM is a direct replacement for part number 20935349 and interchanges with a wide range of other part numbers. It fits the following GM vehicles (please verify location and specific options):
Frequently Asked Questions
How does the cloning service work?
After you place your order, you will ship your original BCM to us. We use specialized equipment to read the unique, vehicle-specific data from your module and write it onto the replacement unit. This ensures the new module is a perfect match for your vehicle’s systems, including keys and security. We then ship both your original module and the ready-to-install replacement back to you.
Why do you need my VIN if you’re cloning my module?
We use your VIN to verify that we are starting with the correct base hardware and to flash the module with the latest, most stable operating software from GM before the cloning process begins. The cloning then transfers your vehicle’s specific key and options data.
Is this a difficult part for a DIYer to replace?
For most individuals with basic mechanical skills, this is a very manageable job. The BCM is typically accessible behind a lower dash panel. The main challenge is carefully removing the plastic trim without breaking any clips. Since our module is plug-and-play, you avoid the most difficult part: the software programming.
What happens if the airbag light comes on after I install it?
This is an infrequent but known possibility on some GM platforms. It means the new BCM and the airbag control module (SDM) need to be electronically ‘introduced.’ This requires a bi-directional scan tool to perform the ‘Setup SDM Primary Key in BCM’ procedure. Most professional repair shops can perform this service for you.
Do you keep my old BCM?
No. We always return your original module along with the programmed replacement unit. We do not require a core and believe you should keep your original parts.