Restore Peak Performance to Your GM Vehicle
Is your 2008 GMC Yukon, Silverado, or other compatible GM vehicle suffering from frustrating issues like a persistent Check Engine Light, erratic shifting, poor fuel economy, or a no-start condition? These are classic signs that the engine’s brain—the Engine Control Module (ECM)—is failing. As a technician with over two decades of experience, I’ve seen firsthand how a faulty ECM can turn a reliable truck into a source of constant headaches. This isn’t just an inconvenience; it affects your vehicle’s safety, reliability, and emissions performance.
This replacement Engine Control Module, part number 12612384, is the definitive solution. It’s not just a part in a box; it’s a complete, ready-to-install fix. We take the hassle and guesswork out of the repair by pre-programming the module to your vehicle’s specific Vehicle Identification Number (VIN). This ensures that it has the latest, most stable software updates directly from GM, correcting factory bugs and optimizing performance. You get a component that communicates flawlessly with your vehicle’s other systems right out of the box, eliminating the need for an expensive trip to the dealership for programming.
A Technician’s Notebook: The Phantom Misfire
I remember a 2008 Sierra 1500 that came into my bay with what the owner described as a “random, violent shudder” at highway speeds. He had already replaced plugs, wires, and a coil pack chasing a misfire that never set a consistent code. My scan tool showed nothing obvious. After checking fuel trims and sensor data, everything looked normal—until it wasn’t. For a split second, I saw the injector pulse width for cylinder 3 drop to zero. The ECM was momentarily cutting fuel for no reason. This is a classic internal processor fault. We installed a VIN-programmed ECM just like this one, and the problem vanished instantly. It’s a reminder that a bad ECM doesn’t always throw a P0601 code; sometimes, the symptoms are much more subtle and frustrating.
Is Your GM Vehicle Showing These Signs?
A failing ECM can manifest in numerous ways. If you’re experiencing any of the following, this module is the likely solution your vehicle needs. Look out for:
- ✔ Persistent and illuminated Check Engine Light
- ✔ Diagnostic Trouble Codes (DTCs) such as P0601, P0602, P0606, or U0100
- ✔ Unexplained drop in fuel mileage
- ✔ Engine stalling, stumbling, or hesitating during acceleration
- ✔ Harsh or erratic automatic transmission shifting
- ✔ Complete no-start or intermittent starting problems
- ✔ Failure to pass state emissions testing
A Straightforward Guide to Installation
Replacing the ECM on these GM trucks and SUVs is a job most DIYers can handle with basic tools. Our pre-programming makes it a true plug-and-play process. Follow these general steps for a successful installation:
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 15 minutes to allow all systems to power down completely.
- Locate the ECM: On most trucks and SUVs like the Yukon, Tahoe, and Silverado, the ECM is located under the hood on the driver’s side, typically under or near the battery tray. On vans like the Express/Savana, it’s often in the LH rear of the engine compartment.
- Disconnect the Connectors: Carefully release the locking tabs on the wiring harness connectors and pull them straight out from the module. Never force them. Inspect the pins for any corrosion or damage.
- Remove the Old Module: Unbolt the mounting hardware holding the old ECM in place and remove it from the vehicle.
- Install the New Module: Mount your new, pre-programmed ECM in the same location and secure it with the original hardware.
- Reconnect Everything: Firmly seat the wiring harness connectors into the new module until they click into place. Reconnect the negative battery terminal.
- Perform Security Relearn: You may need to perform a simple security relearn procedure. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then ‘OFF’ for 10 seconds, and repeating this cycle three times. Your vehicle’s service manual will have the exact steps.
Verified Vehicle Compatibility
This module is a direct replacement for part numbers 12612384, 12622141, and 12617568 and fits a wide range of GM vehicles. Please verify your specific model and engine below. This is a partial list of popular applications:
- ✔ Cadillac: 2008 CTS (3.6L), 2008 Escalade / ESV / EXT
- ✔ Chevrolet: 2008 Avalanche 1500, 2011 Caprice, 2008-2009 Corvette, 2008-2009 Equinox (3.4L), 2008 Express/Savana Vans (Gasoline), 2008 Impala (3.5L/3.9L), 2008 Malibu (3.5L), 2008 Silverado 1500/2500/3500, 2008 Suburban 1500/2500, 2008 Tahoe
- ✔ GMC: 2008 Sierra 1500/2500/3500, 2008 Sierra Denali, 2008 Yukon / XL 1500 / XL 2500 (w/o hybrid)
- ✔ Hummer: 2008 H2
- ✔ Pontiac: 2008 G6 (3.5L/3.9L), 2008-2009 Torrent (3.4L)
- ✔ Saturn: 2008 Aura (3.5L), 2008-2009 Vue (3.5L)
Frequently Asked Questions
What do I need to do after I purchase?
After you place your order, you MUST provide us with your 17-digit Vehicle Identification Number (VIN). We cannot program and ship your module without it. You can typically send it through the order notes or a follow-up message.
Is this a plug-and-play part?
Yes! Because we program it to your VIN before shipping, it is designed to be a plug-and-play installation. In some cases, a simple 10-30 minute security relearn procedure (also known as a CASE relearn) may be required, which does not need special tools.
Will this fix my transmission shifting problems?
In many cases, yes. The ECM works directly with the Transmission Control Module (TCM) to manage shift points. If the ECM is sending faulty data, it can cause poor shifting. A new, correctly programmed ECM often resolves these communication-based transmission issues.
How do I find my original part number?
The part number is printed on a sticker on your original ECM. You can match it to 12612384, 12622141, or 12617568. However, our VIN programming ensures compatibility even if your number differs slightly, as long as your vehicle is on the fitment list.
Do I need to send my old ECM (core) back?
This listing does not require a core return. You can keep or responsibly dispose of your old module, making the process faster and simpler for you.