Restore Peak Performance to Your Hummer H3
If your 2009-2010 Hummer H3 is suffering from frustrating issues like a persistent check engine light, poor acceleration, or even a no-start condition, a failing Engine Control Module (ECM) is often the culprit. As a technician with over two decades of experience, I’ve seen firsthand how a faulty ECM can disrupt everything from fuel delivery to transmission shifting. This isn’t just an inconvenience; it’s a critical component failure that compromises your vehicle’s reliability. We offer a dependable, direct-fit solution: a replacement ECM, part number 12622175, that arrives at your door fully programmed to your vehicle’s specific VIN.
Forget the expensive towing fees and dealership programming appointments. Our process is designed for both seasoned mechanics and dedicated DIYers. Simply provide us with your Hummer’s VIN during checkout, and our specialists will flash the module with the latest, most stable software updates from General Motors. This ensures seamless communication between the ECM and all other vehicle systems, restoring the precise engine management your H3 was designed to have.
Case Study: The Intermittent No-Start H3
A customer brought in a 2009 H3 that would randomly refuse to start. No crank, no click—just silence. It had been to two other shops that replaced the battery and starter to no avail. The issue was intermittent, making it a diagnostic nightmare. After hooking up my scan tool, I noticed a U0100 Lost Communication with ECM/PCM code stored. During testing, I found the 5-volt reference signal from the ECM would occasionally drop out. This tiny electrical fluctuation was enough to prevent the entire system from powering up. We installed a VIN-programmed 2009-2010 Hummer H3 ECM, and the problem was solved instantly. It’s a classic example of how ECM failure can mimic other, more common issues.
Is Your Hummer H3 Showing These Symptoms?
A failing ECM can manifest in numerous ways. If you’re experiencing any of the following, it’s a strong indicator that your engine’s computer needs attention:
- ✔ Persistent Check Engine Light (CEL)
- ✔ Engine stalling, stumbling, or misfiring
- ✔ Vehicle refuses to start or has a hard starting condition
- ✔ Noticeable decrease in fuel economy
- ✔ Transmission shifting issues or harsh shifting
- ✔ Communication error codes (e.g., U0100, U0101)
- ✔ Internal module failure codes (e.g., P0601, P0606)
A Straightforward Guide to Installation
Installing your new 2009-2010 Hummer H3 ECM is a manageable job for anyone with basic tools. Since we handle the programming, you can skip the most complicated step.
- Safety First: Disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent accidental contact.
- Locate the ECM: On the Hummer H3, the ECM is typically located on the right-hand (passenger) side of the firewall in the engine compartment.
- Disconnect Connectors: Carefully release the locking tabs on the electrical wiring harnesses and pull them straight out from the module. Avoid pulling on the wires themselves.
- Remove the Old Module: Unbolt the old ECM from its mounting bracket. There are usually a few bolts holding it in place.
- Install the New Module: Mount your new, pre-programmed ECM onto the bracket and secure it with the bolts.
- Reconnect Everything: Firmly plug the wiring harnesses back into the new ECM until they click into place. Reconnect the negative battery terminal.
- Final Step: Some vehicles may require a security relearn procedure, which can often be done without special tools. A common method is to turn the key to the ‘ON’ position for 10-15 minutes, then ‘OFF’ for 10 seconds, and repeat three times before starting the engine. Consult your owner’s manual for specific instructions.
Verified Vehicle Compatibility
This ECM is a direct replacement for part number 12622175 and is interchangeable with service numbers: 12636659, 12639300, 1263605, 12628993, 12628911, 12625453, 12630464, and 12678512. It is guaranteed to fit the following vehicles:
- ✔ HUMMER H3 2009-2010 (RH firewall)
- ✔ CADILLAC CTS 2009 (6.2L)
- ✔ CADILLAC DTS 2009-2011
- ✔ CADILLAC SRX 2009 (4.6L)
- ✔ CADILLAC STS 2009-2010 (4.4L, 4.6L)
- ✔ CADILLAC XLR 2009
- ✔ CHEVROLET COLORADO 2009-2012 (2.9L, 3.7L)
- ✔ CHEVROLET CORVETTE 2009 (ZR1)
- ✔ CHEVROLET TRAILBLAZER 2009 (6.0L)
- ✔ GMC CANYON 2009-2012 (2.9L, 3.7L)
- ✔ GMC ENVOY 2009 (5.3L)
- ✔ BUICK LUCERNE 2009-2011 (4.6L)
- ✔ SAAB 9-7X 2009
Frequently Asked Questions
Frequently Asked Questions
Do I need to do any programming after I receive the ECM?
No. We program the module to your vehicle’s VIN before shipping. In most cases, it is a plug-and-play installation, although some vehicles may require a simple key relearn procedure that you can do yourself.
Where do I find my VIN?
Your 17-digit Vehicle Identification Number (VIN) can be found on your vehicle’s registration, insurance card, or on a placard on the driver’s side of the dashboard visible through the windshield.
Is this a reliable replacement for my 2009-2010 Hummer H3 ECM?
Absolutely. This module is a quality replacement part that meets or exceeds original equipment specifications. It is loaded with the latest GM software to ensure optimal performance and longevity.
What happens if I don’t provide a VIN?
Providing your VIN is mandatory for this part. We cannot ship the module without programming it, as it will not function correctly in your vehicle. This step ensures you receive a part that works right out of the box.
Will this fix my check engine light?
If the check engine light is caused by an internal failure of the ECM (e.g., codes P0601-P0606), then yes, this will resolve the issue. However, you should always diagnose the codes to ensure the problem isn’t a faulty sensor or wiring.