Programmed 2007 HUMMER H2 ECM Engine Control Module 12597121

Is Your HUMMER H2 Running Rough? Get Back in Command.

As a technician with over two decades of experience under the hood, I’ve seen countless drivers frustrated by mysterious engine problems. Stalling at intersections, a persistent check engine light, poor fuel economy, or a complete no-start condition can sideline even the most rugged vehicle like your 2007 HUMMER H2. Often, the culprit is the very brain of the operation: the Engine Control Module (ECM). When the ECM fails, it can send incorrect signals—or no signals at all—to critical components, leading to a cascade of performance issues that can be a nightmare to diagnose.

This isn’t just a replacement part; it’s a direct solution. We offer a reliable Engine Control Module, part number 12597121, that arrives at your door programmed specifically for your vehicle. Simply provide us with your VIN after purchase, and we’ll flash the module with the latest, most stable GM software updates. This critical step ensures seamless communication with your H2’s systems, restoring the performance and reliability you depend on. It’s the dealership-level solution without the dealership price tag or hassle.

Is Your Truck Showing These Symptoms?

A failing ECM can manifest in various ways. If you’re experiencing any of the following, this module is the likely solution.

• ✔ Check Engine Light is on with codes like P0601, P0606, or other communication errors.
• ✔ Engine cranks but refuses to start.
• ✔ Unexplained drops in fuel efficiency.
• ✔ Rough or erratic idling and stalling.
• ✔ Noticeable loss of power and poor acceleration.
• ✔ Transmission shifting issues or harsh shifts.
• ✔ The vehicle enters a reduced power or “limp” mode.

A Straightforward Guide to Installation

Installing your new 2007 HUMMER H2 ECM is a manageable job for a confident DIYer. On the H2, the module is located in the engine bay, on the driver’s side, typically under the battery tray. Always prioritize safety.

1. Safety First: Disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent accidental reconnection.
2. Access the Module: You will likely need to remove the battery and the battery tray to gain clear access to the ECM. Keep track of all fasteners.
3. Disconnect the Connectors: Carefully unclip the wiring harness connectors from the old ECM. These connectors have locking tabs; do not force them. Inspect the pins for any corrosion or damage before proceeding.
4. Remove the Old ECM: Unbolt the old module from its mounting bracket.
5. Install the New ECM: Mount your new, pre-programmed module in place and securely fasten it.
6. Reconnect Everything: Plug the wiring harnesses firmly into the new ECM until they click. Reinstall the battery tray and the battery, then reconnect the negative battery terminal.
7. Security Relearn: In many cases, you may need to perform a simple security relearn procedure (often called a “key-on, key-off” cycle) to sync the new ECM with your vehicle’s anti-theft system. This procedure can typically be found in your owner’s manual or online and requires no special tools.

Guaranteed Fitment for Your GM Vehicle

This module is a direct-fit replacement, programmed for your specific vehicle. It is compatible with part numbers 12589297, 12597121, 12603892, and 19210738 and fits a wide range of GM trucks, SUVs, and cars. Please verify your vehicle is on the list below for guaranteed compatibility.

Frequently Asked Questions