Restore Your Vehicle’s Brainpower and Performance
If your Pontiac G6, Chevy Silverado, or other compatible GM vehicle is suffering from frustrating issues like a persistent Check Engine Light, rough idling, stalling, or a complete no-start condition, the problem often lies with a failing Engine Control Module (ECM). As an automotive technician with over two decades of diagnostic experience, I’ve seen firsthand how a faulty ECM can wreak havoc on a vehicle’s entire system. It’s the central computer, and when it starts to fail, it can send you chasing phantom sensor issues for weeks. This isn’t just an inconvenience; it affects your car’s reliability, fuel economy, and safety.
This isn’t just a replacement part; it’s a complete solution. We take the hassle and high cost of dealership programming out of the equation. Simply provide us with your vehicle’s VIN during checkout, and our experts will program this ECM with the very latest, most stable software updates directly from GM. This ensures that when the part arrives at your door, it’s ready for a straightforward installation, restoring your vehicle’s factory performance and communication protocols.
A Technician’s Notebook: The Intermittent G6 Gremlin
I remember a 2009 Pontiac G6 that came into the shop with a problem that was driving the owner crazy. It would start fine for a week, then refuse to start for a day. Other times, the transmission would shift erratically. The customer had already replaced the battery and alternator. After hooking up my high-level scan tool, I noticed intermittent communication loss with the ECM (a classic U0100 code). The module’s internal processors were failing under certain temperature conditions. Instead of a costly diagnostic path and a trip to the dealer, we installed a VIN-programmed ECM just like this one. The fix was immediate and permanent. It’s a perfect example of how the right part, correctly prepared, can save hundreds in labor and diagnostic fees.
Is Your Vehicle Showing These Symptoms of ECM Failure?
A failing engine computer can manifest in numerous ways. If you’re experiencing any of the following, a faulty ECM is a likely culprit:
- ✔ Persistent Check Engine Light (CEL) that won’t clear
- ✔ Engine stalling or misfiring for no apparent reason
- ✔ Vehicle refuses to start, even with a good battery and starter
- ✔ Noticeable drop in fuel efficiency
- ✔ Poor or erratic automatic transmission shifting
- ✔ Communication error codes, such as U0100, or internal module failure codes like P0601 or P0606
- ✔ Issues with other electronic systems that rely on ECM data
Your Straightforward Guide to Installation
Installing your new 2009 G6 Engine Computer is a manageable job for a confident DIYer. Taking your time and following these steps will ensure a smooth process. The ECM on the G6 is typically located in the left-hand (driver’s side) front of the engine compartment.
- 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 listed models, you’ll find it in the engine bay, often near the firewall or air filter box. It’s a metal box with several large electrical connectors.
- Disconnect the Connectors: Carefully unlatch and remove the electrical wiring harnesses from the old ECM. These connectors have locking tabs; never force them. Inspect the pins for any corrosion or damage.
- Remove the Old Module: Unbolt the old ECM from its mounting bracket. Keep the hardware, as you may need it for the new module.
- Install the New ECM: Mount your new, pre-programmed ECM securely onto the bracket and re-tighten the bolts.
- Reconnect Everything: Firmly plug the wiring harnesses back into the new module until they click into place. Reconnect the negative battery terminal.
- Final Steps: Some vehicles may require a security relearn procedure, which can often be done by cycling the key. Turn the key to the ‘ON’ position for 10-15 minutes, then ‘OFF’ for 10 seconds, and repeat two more times before attempting to start the engine. Your vehicle is now ready to go!
Verified Vehicle Compatibility
This module, part number 12629009, is a direct replacement for service number 12625455 and fits a wide range of General Motors vehicles. Please verify your specific model and engine option below. Providing your VIN is the best way to guarantee perfect compatibility.
- Pontiac G6 (2009): 3.5L & 3.9L Engines
- Chevrolet Silverado 1500/2500/3500 (2009-2010): Various engines including 6.0L
- GMC Sierra 1500/2500/3500 (2009-2010): Various engines including 6.0L
- Chevrolet Suburban / Tahoe (2009-2010)
- GMC Yukon / Yukon XL (2009-2010)
- Cadillac Escalade / ESV / EXT (2009-2010): 6.2L Engine
- Chevrolet Express & GMC Savana Vans (2009): 4.8L, 5.3L, & 6.0L Engines
- Chevrolet Impala (2009): 3.5L & 3.9L Engines
- And many more models including the Corvette, Hummer H2, Malibu, G8, and Vue.
The ECM is your vehicle’s main computer. It controls critical functions like fuel injection timing, spark timing, and transmission shifts to ensure the engine runs efficiently and cleanly. When it fails, the entire vehicle’s performance is compromised.
No! That’s the primary benefit of our service. We program the module to your car’s specific VIN before we ship it. This makes it a plug-and-play solution, saving you the time, towing fees, and high labor costs of dealership programming.
The Vehicle Identification Number (VIN) allows us to load the exact factory software and calibrations for your car’s specific engine, transmission, and options. This ensures seamless integration and proper function, just like the original part.
On the 2009 Pontiac G6, the ECM is typically located in the front of the engine compartment on the driver’s side (LH side), often near the air filter housing or firewall.
While this part resolves the vast majority of issues listed in the symptoms section, we always recommend a proper diagnosis. However, if your mechanic has condemned the ECM or you have clear signs of module failure (like communication codes), this is the correct, reliable fix.
Yes, this ECM (12629009) is a fully compatible and often updated replacement for the original part number 12625455, covering all the same applications.