Restore Full Functionality to Your GM SUV
Are you battling frustrating and unpredictable electrical problems in your Chevrolet Trailblazer, GMC Envoy, or other GM SUV? Issues like flickering lights, malfunctioning power windows, a dead instrument cluster, or a security system that has a mind of its own are often not isolated failures but symptoms of a failing Body Control Module (BCM). The BCM acts as the central command center for your vehicle’s body electronics, and when it starts to fail, it can cause a cascade of confusing and annoying problems. This pre-programmed Body Control Module, part number 15191621, is the definitive solution to restore your vehicle’s electronic systems to perfect working order.
From the Diagnostic Bay
We recently had a 2004 GMC Envoy in the shop with a laundry list of bizarre electrical gremlins. The power locks would cycle randomly while driving, the radio would lose its presets, and the dome light would stay on intermittently. The owner had spent hundreds chasing the issue, replacing switches and checking grounds to no avail. After connecting our diagnostic tool, we saw multiple communication errors pointing directly at the BCM. Instead of a costly trip to the dealer for a new module and programming, we installed a VIN-programmed Trailblazer Envoy BCM just like this one. The installation was straightforward, and instantly, all the strange electrical issues were gone. It’s a common failure on these GMT360 platform vehicles, and a correctly programmed module is the key to a lasting repair.
Is Your BCM Failing? Check for These Symptoms:
- ✔ Erratic power windows, door locks, or power mirrors that work intermittently or not at all.
- ✔ Interior or exterior lights (headlights, taillights, dome lights) staying on, flickering, or not turning on.
- ✔ The security system engaging randomly, causing the horn to honk or preventing the vehicle from starting.
- ✔ Instrument cluster gauges behaving erratically or going completely dead.
- ✔ The radio or climate control system malfunctioning or losing power.
- ✔ Warning lights such as the airbag light, ABS, or “Service 4WD” light appearing on the dash.
- ✔ Communication issues with diagnostic scan tools, preventing proper vehicle diagnosis.
The Plug-and-Play Solution Dealers Don’t Offer
Replacing a BCM typically involves purchasing an expensive blank module from a dealership, followed by hours of labor for installation and programming with specialized equipment. We’ve eliminated that hassle. When you order from us, you provide your vehicle’s VIN, and we program the module for you before it ships. It arrives at your door loaded with the latest GM software updates specific to your vehicle, making the installation process as simple as swapping the part. This saves you time, money, and the headache of coordinating with a dealership service center.
Important Post-Installation Procedures
While this Trailblazer Envoy BCM is programmed for a plug-and-play installation, certain vehicle systems may require a recalibration or sync procedure after the new module is installed. This is a normal part of the repair process.
- Airbag System Sync: If your airbag warning light illuminates after installation, it means the new BCM needs to be synced with the vehicle’s SDM (Sensing and Diagnostic Module). A professional scan tool is required to perform the “Setup SDM Primary Key in BCM” procedure. This is a quick process for any qualified technician.
- Brake Pedal Position Relearn: On some models, a brake pedal position sensor recalibration may be necessary. This ensures your brake lights function correctly and the traction control system operates as designed.
Always consult a factory service manual or a qualified technician for specific instructions related to your vehicle.
Guaranteed Fitment for Your Vehicle
This module is a direct replacement for a wide range of GM SUVs and replaces multiple original part numbers, ensuring compatibility. Please verify your vehicle is on the list below.
Replaces Part Numbers: 15122670, 15065293, 15114669, 15191621, 9352135
Fits the following vehicles:
- 2002-2005 Chevrolet Trailblazer & Trailblazer EXT
- 2002-2005 GMC Envoy, Envoy XL, & Envoy XUV
- 2002-2004 Oldsmobile Bravada
- 2004-2005 Buick Rainier
- 2003-2005 Isuzu Ascender
- 2005 Saab 9-7X
Frequently Asked Questions
Is this BCM truly plug-and-play?
Yes, it is. We program the module using the VIN you provide during checkout. This ensures it has the correct software and configuration for your vehicle’s specific options, allowing for a direct installation without needing a trip to the dealer.
Where do I find my vehicle’s VIN?
Your 17-digit Vehicle Identification Number (VIN) can be found on the driver’s side of the dashboard (visible through the windshield), on the driver’s side door jamb sticker, or on your vehicle’s registration and insurance documents.
What happens if I forget to provide my VIN?
We cannot ship the module until we receive your VIN. Programming is a required step for the part to function in your vehicle. We will contact you via email to request the VIN if it’s not provided with the order.
Do I need to return my old BCM?
No, there is no core charge for this module. You can keep your original part.
My airbag light is on after installing the new BCM. Is it defective?
No, this is normal. The new BCM needs to be electronically ‘introduced’ to the airbag system’s computer (SDM). A technician with a professional scan tool must perform the ‘Setup SDM Primary Key in BCM’ procedure to sync the systems and turn off the light.
Will this fix my ‘Service 4WD’ light?
A faulty BCM can cause a ‘Service 4WD’ light because it disrupts communication with the Transfer Case Control Module (TCCM). While replacing the BCM often resolves this, the issue could also be with the TCCM or the front axle actuator. Further diagnosis may be required if the light persists.