Restore Peak Performance to Your HUMMER H3
Is your 2009-2010 HUMMER H3 suffering from frustrating and unpredictable issues like stalling, a persistent check engine light, or a complete no-start condition? These are classic signs of a failing Engine Control Module (ECM), the central computer that manages your vehicle’s engine performance, fuel delivery, and emissions. When it falters, it can make your otherwise rugged H3 feel unreliable. This replacement ECM, part number 12622175, is the definitive solution to restore your vehicle’s factory performance and your peace of mind.
What sets this module apart is our professional programming service. Before we ship your part, we flash it with the latest official GM software updates, specifically matched to your vehicle using your VIN. This means it arrives at your door ready for installation, saving you the time, cost, and hassle of a trip to the dealership for expensive programming. Get your H3 back on the road and running smoothly with a component you can trust.
A Technician’s Notebook: The Phantom No-Start H3
I once had a 2009 H3 in my bay that was a real head-scratcher. The owner said it would randomly refuse to start, but then an hour later, it would fire right up. The battery was good, the starter was fine, and there were no consistent trouble codes—just an intermittent U0100 (Lost Communication with ECM). After hours of tracing wires and checking grounds, we swapped in a known-good, programmed ECM. The problem vanished instantly. The original module had an internal hairline fracture that would separate when hot, cutting communication. This is why for intermittent electrical gremlins, a reliable 2009-2010 HUMMER H3 ECM is often the root cause and the only true fix.
Common Signs of a Failing Engine Control Module
- ✔ Check Engine Light is illuminated with codes like P0601, P0606, or U0100.
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained stalling or rough idling.
- ✔ Noticeable decrease in fuel economy.
- ✔ Poor engine performance, hesitation, or misfires.
- ✔ Communication issues with diagnostic scan tools.
- ✔ Problems with the automatic transmission shifting correctly.
A Straightforward Guide to Installation
- ✔ Safety First: Always disconnect the negative terminal from your vehicle’s battery before beginning any electrical work.
- ✔ Locate the ECM: On the 2009-2010 HUMMER H3, the ECM is typically located on the right-hand (passenger) side of the firewall in the engine bay.
- ✔ Disconnect Connectors: Carefully release the locking tabs and unplug the wiring harnesses from the old module. Inspect the connectors for any corrosion or damage.
- ✔ Remove the Old Module: Unbolt the old ECM from its mounting bracket.
- ✔ Install the New Module: Mount your new, pre-programmed 2009-2010 HUMMER H3 ECM in place and securely fasten it.
- ✔ Reconnect Everything: Plug the wiring harnesses back into the new module, ensuring they click into place. Reconnect the negative battery terminal.
- ✔ Final Steps: In some cases, a security relearn procedure may be needed, which can typically be done without special tools by cycling the key. Your vehicle’s service manual will have specific instructions. Start the engine and confirm the check engine light is off.
Verified Vehicle Compatibility
This ECM is a direct-fit replacement for a wide range of GM vehicles and is interchangeable with service numbers 12636659, 12639300, 1263605, 12628993, 12628911, 12625453, 12622175, 12630464, and 12678512. Please confirm your vehicle is on this list:
- 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): ID 12636659 or 12625453
- 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
- HUMMER H3 (2009-2010): Including 3.7L models
- LUCERNE (2009-2011): 4.6L
- SAAB 9-7X (2009)
A properly functioning 2009-2010 HUMMER H3 ECM is essential for your vehicle’s health. Don’t let a faulty module keep you off the road. Order today and experience the difference a quality, professionally programmed component makes.
Frequently Asked Questions
Do I need to program this ECM?
No. We handle all the programming for you before shipment. Simply provide your vehicle’s VIN during checkout, and it will arrive ready to install.
Where is the ECM located on my 2010 HUMMER H3?
The Engine Control Module on the H3 is mounted to the firewall on the passenger side of the engine compartment.
What happens if I forget to provide my VIN?
We cannot program and ship the module without your vehicle’s 17-digit VIN. We will contact you to retrieve this information, which may delay your order.
Will this fix my check engine light?
If the check engine light is caused by a faulty ECM (e.g., internal processor error codes), then this part will resolve the issue. It’s crucial to have a proper diagnosis to confirm the ECM is the point of failure.
Is this a difficult part for a DIYer to install?
For someone with basic mechanical skills and common hand tools, this is a very manageable job. The most important parts are being careful with the electrical connectors and ensuring the battery is disconnected.