Restore Full Electrical Function to Your HUMMER H2
If you’re dealing with baffling electrical issues in your 2008-2009 HUMMER H2—like power windows with a mind of their own, flickering lights, or a security system that won’t cooperate—the Body Control Module (BCM) is the most likely culprit. As a technician with over two decades of experience, I’ve seen how a failing BCM can turn a reliable vehicle into a source of constant frustration. This module acts as the central hub for your truck’s body electronics, and when it fails, chaos ensues. This replacement 2008-2009 HUMMER H2 BCM is the direct, reliable solution you need to get your vehicle back to 100%.
Case Study: The Phantom Power Drain
A customer brought in his ’08 H2 with a dead battery every morning. He’d already replaced the battery and alternator. After hooking up my multimeter, I found a significant parasitic draw. Tracing the circuits led me straight to the BCM. Internally, a faulty relay was keeping a circuit live long after the key was off. Swapping in a VIN-programmed BCM like this one didn’t just solve the battery drain; it also fixed his intermittently working radio and dome lights. It’s a perfect example of how one component can cause multiple, seemingly unrelated symptoms.
Is Your HUMMER H2 Showing These Symptoms?
A faulty BCM can manifest in numerous ways. Here are the most common signs I’ve diagnosed in my shop. If you’re experiencing several of these, it’s time to check your BCM.
- ✔ Erratic or non-functional power windows, door locks, and mirrors.
- ✔ Interior or exterior lights flickering, staying on, or not working at all.
- ✔ The security system acting up, causing no-start conditions or false alarms.
- ✔ The radio or instrument cluster display behaving erratically.
- ✔ Communication error codes, such as U0140 (Lost Communication With Body Control Module), stored in other modules.
- ✔ Wipers operating intermittently or not parking in the correct position.
A Straightforward Guide to BCM Installation
Installing your new 2008-2009 HUMMER H2 BCM is a manageable job for a confident DIYer. In the H2, the BCM is typically located on the left-hand (driver’s side) firewall, inside the cabin. Always confirm the location in a service manual for your specific vehicle.
- Safety First: Disconnect the negative terminal from your vehicle’s battery and wait at least 10 minutes to allow capacitors to discharge.
- Access the Module: You may need to remove lower dash panels or trim to gain clear access to the BCM on the LH firewall.
- Disconnect and Remove: Carefully unplug the electrical connectors. They have locking tabs that must be depressed. Once disconnected, unbolt the old BCM from its mounting bracket.
- Install the New BCM: Mount the new, pre-programmed BCM in the same location and securely fasten it. Reconnect all electrical connectors, ensuring they click into place.
- Final Steps: Re-install any trim panels you removed. Reconnect the negative battery terminal. Start the vehicle and test all functions (windows, locks, lights, etc.).
Important Post-Installation Information
Because this module is central to many systems, a couple of additional steps may be required after installation:
- ✔ Airbag System Sync: If the airbag warning light is illuminated 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 needed to ensure correct brake light and traction control operation. This also typically requires a compatible diagnostic tool.
Disclaimer: Vehicle systems vary. We always recommend consulting a factory service manual or a certified technician if you are unsure about any part of the process.
Will This Fit My Vehicle?
This BCM is a direct replacement for part number 20815898 and a wide range of other GM part numbers. It is guaranteed to fit the following vehicles. Please verify your model and any specific ID numbers mentioned.
Vehicle Fitment:
HUMMER H2 08-09 Body Control (BCM); (LH firewall)
ACADIA 07-12 Body Control (BCM); (LH dash)
AVALANCHE 1500 10 Body Control (BCM); (under steering column), ID 25892622
CAPRICE 11-13 Body Control (BCM)
CAPTIVA SPORT 12 Body Control (BCM); (center dash), ID 20921435, 20921436, 22860591
CTS 08-13 Body Control (BCM); LH dash
DTS 06-11 Body Control (BCM); (RH center dash)
ENCLAVE 08-12 Body Control (BCM); (LH dash)
EQUINOX 07-09 Body Control (BCM); (center dash)
ESCALADE 10 Body Control (BCM); (under steering column), ID 20815898, 25892622
ESCALADE ESV 10 Body Control (BCM); (under steering column), ID 20815898, 25892622
ESCALADE EXT 10 Body Control (BCM); (under steering column), ID 25892622
EXPRESS/SAVANA VANS 08-12 (See full list in original data for specific engines/options)
G8 08-09 Body Control (BCM); (center dash)
IMPALA 06-13 (See full list for specific IDs)
LUCERNE 06-11 Body Control (BCM); (right side dash)
MONTE CARLO 06-07 Body Control (BCM); (LH steering column)
OUTLOOK 07-10 Body Control (BCM); (center dash)
SRX 07-09 Body Control (BCM); LH dash
STS 10 Body Control (BCM); center dash
SUBURBAN 1500 10 Body Control (BCM); (under steering column), ID 20815898, 25892622
TAHOE 10 Body Control (BCM); (under steering column), ID 20815898, 25892622
TORRENT 07-09 Body Control (BCM); (center dash)
TRAVERSE 09-12 Body Control (BCM); (LH dash)
VUE 08-10 Body Control (BCM); (center dash)
YUKON / YUKON XL 1500 10 Body Control (BCM); (under steering column), ID 20815898, 25892622
Frequently Asked Questions
Do I need to program this BCM?
No. We handle the programming for you before shipping. Simply provide your vehicle’s 17-digit VIN during or after checkout, and we will flash the module with the latest GM software specific to your H2.
What is a core charge?
A core charge is a deposit you pay until you return your old part. We do not have a core charge on this item. You can keep your old BCM, which is helpful if you ever need to reference it.
Where is the BCM located on my 2009 HUMMER H2?
On the 2008-2009 HUMMER H2, the Body Control Module is located inside the vehicle’s cabin, mounted to the firewall on the driver’s side (LH side), typically behind the lower dash panel.
What tools do I need for the installation?
Basic hand tools like a socket set and screwdrivers are usually sufficient to remove the trim panels and unbolt the old BCM. No special programming tools are required as we handle that for you.
My airbag light is on after installing the new BCM. What should I do?
This is normal in some cases. The new BCM needs to be electronically ‘introduced’ to the airbag system’s computer (SDM). This requires a professional scan tool to perform the ‘Setup SDM Primary Key in BCM’ procedure to sync the modules and clear the light.