Restore Peak Performance to Your Hummer H3
Is your 2009-2010 Hummer H3 suffering from frustrating issues like a persistent check engine light, rough idling, stalling, or poor fuel economy? These are common indicators of a failing Engine Control Module (ECM), the central computer that manages your vehicle’s engine performance, fuel delivery, and emissions. A faulty ECM can cripple your vehicle’s reliability and leave you stranded. This direct-replacement ECM, part number 12630464, is the definitive solution to restore your Hummer’s factory performance and dependability.
The Brain of Your Operation: The Role of the ECM
The ECM in your Hummer H3 is a sophisticated computer that processes data from dozens of sensors throughout your engine and powertrain. It makes real-time adjustments to the fuel-to-air ratio, ignition timing, and transmission shift points to ensure optimal power, efficiency, and low emissions. When it begins to fail, the entire system can become erratic, leading to a cascade of performance problems that can be difficult to diagnose. Replacing a failing unit with a generic, unprogrammed module often leads to more headaches, compatibility issues, and additional trips to the mechanic. Our solution eliminates that guesswork.
From the Diagnostic Bay
We had a 2010 Hummer H3 come into the shop with an issue that had stumped two other mechanics. The owner complained of random stalling at traffic lights and an intermittent misfire that never seemed to store a consistent trouble code. We checked the fuel pressure, spark plugs, and ignition coils, all of which were fine. After connecting our diagnostic tool, we noticed the live data stream from the ECM would occasionally drop out or show erratic sensor readings, even when the sensors themselves tested good. This pointed to an internal failure in the module. We installed a VIN-programmed 2009-2010 Hummer H3 ECM, performed the security relearn, and the truck ran perfectly. The intermittent stalling vanished, and the owner was thrilled to have his reliable H3 back.
Common Symptoms of a Failing Hummer H3 ECM
- ✔ Persistent Check Engine Light (CEL) with various trouble codes.
- ✔ Engine stalling, stumbling, or hesitating during acceleration.
- ✔ Noticeable decrease in fuel efficiency.
- ✔ Complete no-start or hard-starting conditions.
- ✔ Rough or erratic engine idling.
- ✔ Harsh or incorrect automatic transmission shifting.
- ✔ Communication errors when using a diagnostic scan tool.
Why Choose Our Programmed 2009-2010 Hummer H3 ECM?
This isn’t just a replacement part; it’s a complete, ready-to-install solution. We take the hassle and expense out of the repair process. When you order, you provide us with your vehicle’s VIN. Our technicians then program the module with the latest, most up-to-date software directly from GM for your specific vehicle configuration. This ensures perfect compatibility and function right out of the box, eliminating the need for expensive dealership programming.
This module is a direct fit for the 2009-2010 Hummer H3 and is also interchangeable with a wide range of other GM vehicles, making it a versatile and reliable component. It is a direct replacement for the following service numbers: 12636659, 12639300, 1263605, 12628993, 12628911, 12625453, 12622175, 12630464, and 12678512.
Installation and Compatibility
This ECM is located on the right-hand (passenger side) firewall of your Hummer H3. While installation is a straightforward unbolt-and-replace process, please be aware that a security relearn procedure (often called a ‘key relearn’ or ‘anti-theft relearn’) may be necessary for your vehicle to start after the new ECM is installed. This procedure can typically be performed by the owner without special tools and instructions are widely available online or in your vehicle’s service manual.
Frequently Asked Questions
Do I need to have this ECM programmed by a dealer?
No. We handle all the programming for you before shipment. Simply provide your vehicle’s VIN during checkout, and we will flash the module with the correct GM software for your specific Hummer H3.
Is this a simple plug-and-play installation?
It is a direct physical fit and electronically programmed for your vehicle. However, you may need to perform a security relearn procedure to sync the new ECM with your vehicle’s anti-theft system. This is a standard step for this type of repair.
Where do I enter my VIN?
You can provide your Vehicle Identification Number (VIN) in the notes section during the checkout process or reply to your order confirmation email with the information. We cannot ship your part until we have your VIN.
My original part number is different. Will this still work?
Yes, as long as your original part number is on the interchange list provided (e.g., 12636659, 12628993, etc.). GM often supersedes part numbers, and this module is a verified replacement for all listed service numbers.
What is the warranty on this part?
This engine control module comes with a comprehensive warranty that covers any defects in materials or workmanship. Please see our warranty page for full details and duration.