Restore Full Functionality to Your GM SUV
Are you dealing with baffling electrical issues in your Trailblazer, Envoy, or other GM SUV? Flickering dashboard lights, power windows with a mind of their own, or a radio that cuts out unexpectedly are more than just annoyances—they’re classic signs of a failing Body Control Module (BCM). As the central hub for your vehicle’s body electronics, a faulty BCM can cause a cascade of frustrating and seemingly unrelated problems. This isn’t just a part; it’s the solution to restoring the reliable performance you depend on every day.
This replacement BCM, part number 15114669, is the definitive fix. Unlike sourcing a used module from a junkyard that requires expensive dealership programming, this unit arrives at your door completely programmed to your vehicle’s specific VIN. We load the latest, most stable software from GM, ensuring all electronic systems communicate correctly right out of the box. This saves you time, money, and the headache of scheduling a dealership appointment.
Real-World Repair Story
Real-World Repair Story
I remember a 2004 Trailblazer that came into my shop with a laundry list of complaints from the owner. The dome light wouldn’t turn off, the driver’s side power window worked only intermittently, and the vehicle would occasionally refuse to crank. The owner had already replaced the battery and alternator. After hooking up my scan tool, I saw a dozen communication codes (U-codes) pointing to a network failure. Instead of chasing each symptom, experience told me to look at the central hub: the BCM. A quick check of the BCM’s connectors revealed no corrosion, confirming an internal failure. We installed one of these pre-programmed BCMs, and in under an hour, every single issue was resolved. It’s a perfect example of how one component can cause widespread electrical chaos.
Common Signs of a Failing BCM
If your vehicle is experiencing any of the following, a faulty BCM is the most likely culprit. A failing module can often generate communication-related Diagnostic Trouble Codes (DTCs), such as U0140, U0155, or U0164.
- ✔ Erratic or non-functional power windows, door locks, and mirrors.
- ✔ Interior or exterior lights staying on or not working at all.
- ✔ Gauges on the instrument cluster behaving erratically or dropping to zero.
- ✔ The security or anti-theft system preventing the vehicle from starting.
- ✔ Intermittent issues with the radio or climate control system.
- ✔ False warnings on the driver information center.
A Straightforward Guide to Your BCM Installation
Replacing the BCM is a manageable job for a DIYer with basic tools. The module is typically located behind the rear seat on the driver’s side, integrated with the fuse panel.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before beginning any electrical work.
- Access the Module: Locate the rear fuse block. You may need to fold down the rear seat and remove a plastic cover or panel to gain access.
- Disconnect Connectors: Carefully unplug all the electrical connectors from the old BCM. They have locking tabs that must be depressed to be removed. Don’t force them.
- Remove the Old BCM: Unbolt or unclip the old BCM/fuse block assembly from its mounting location.
- Install the New BCM: Mount your new, pre-programmed BCM in the same location and securely reconnect all the electrical connectors.
- Reconnect Battery & Test: Reconnect the negative battery terminal. Turn the key to the ‘On’ position and test all functions: windows, locks, lights, radio, etc., to confirm the repair.
Important Post-Installation Notes
While this BCM is programmed for a plug-and-play installation, certain vehicle systems may require a recalibration procedure after the new module is installed.
- Airbag System Sync: If the airbag warning light is illuminated after installation, a simple ‘Setup SDM Primary Key in BCM’ procedure must be performed using a professional-grade scan tool. This syncs the new BCM with the airbag system.
- Brake Pedal Position Relearn: On some models, a brake pedal position sensor relearn may be needed to ensure correct brake light operation and to prevent issues with the traction control system.
Disclaimer: Vehicle systems vary. Always refer to a factory service manual or a certified mechanic if you are unsure about any step.
Verified Vehicle Compatibility
This BCM is a direct-fit replacement for the following vehicles and part numbers. Please verify your vehicle and options before ordering. It is a compatible replacement for part numbers: 15122670, 15065293, 15114669, 15191621, and 9352135.
- Bravada: 2002-2004
- Envoy: 2002-2005
- Envoy XL: 2002-2005
- Envoy XUV: 2004-2005
- Isuzu Ascender: 2003-2005
- Rainier: 2004-2005
- Saab 9-7X: 2005
- Trailblazer: 2002-2005
- Trailblazer EXT: 2002-2005
Why do I need to provide my VIN?
Your Vehicle Identification Number (VIN) allows us to program the Body Control Module with the exact software and calibrations your vehicle had when it left the factory, plus any available GM updates. This ensures all your specific options (like power seats, sunroof, etc.) work correctly without a trip to the dealer.
Is this a difficult part to replace myself?
For someone with basic mechanical skills, this is a very manageable job. The BCM is typically easy to access, and since we pre-program it, the most complex part of the process is already done for you. The main steps involve disconnecting the battery and swapping electrical connectors.
What happens if the airbag light comes on after I install it?
This is a known possibility. It simply means the new BCM needs to be electronically ‘introduced’ to your vehicle’s airbag module (SDM). A repair shop with a capable bi-directional scan tool can perform the ‘Setup SDM Primary Key in BCM’ procedure in a few minutes to resolve this.
Do I need to send my old BCM back?
No, there is no core charge for this part. You can keep your original module.
Will this BCM fix my no-start problem?
A failing BCM is a common cause of intermittent no-start or no-crank conditions, especially if the security light is on. If the BCM is failing to communicate with the powertrain control module or recognize the key, replacing it can solve the problem. However, you should always perform a complete diagnosis, as other parts like the starter or ignition switch can cause similar symptoms.