Restore Your Vehicle’s Brain and Get Back on the Road
Is your vehicle suffering from frustrating, hard-to-diagnose electrical gremlins? A failing Engine Control Module (ECM) is often the culprit behind issues like stalling, poor fuel economy, erratic behavior, or a dreaded no-start condition. As the central computer for your engine, its proper function is critical. This replacement 2009 Corvette Engine Control Module, part number 12639300, is the reliable, straightforward solution you need. We take the guesswork and extra cost out of the repair by pre-programming the module to your vehicle’s specific VIN before it ships. This means no extra trips to the dealership for expensive flashing—it’s ready for installation right out of the box.
A Technician’s Notebook: The Ghost in the Machine
I once had a 2010 GMC Canyon in my bay that was driving the owner crazy. It would randomly stall at red lights, but never threw a consistent code. The owner had already replaced the crank sensor and a throttle body based on forum advice, with no luck. After hooking up my scope, I noticed the 5-volt reference signal to the sensors would occasionally drop out for just a millisecond—too fast to set a specific sensor code, but long enough to stall the engine. The issue wasn’t the sensors; it was the ECM itself failing internally. We installed a VIN-programmed module just like this one, and the truck ran perfectly. It’s a classic case where chasing individual symptoms can be costly, while addressing the root cause—the ECM—provides the real fix.
Common Signs of a Failing ECM
- ✔ Check Engine Light is on with communication-related Diagnostic Trouble Codes (DTCs) like P0601, P0606, or U0100.
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained drops in fuel efficiency and engine performance.
- ✔ Intermittent stalling or rough idling for no apparent reason.
- ✔ Automatic transmission shifts harshly or at the wrong times.
- ✔ Other modules on the vehicle cannot communicate with the ECM.
A Straightforward Guide to Installation
Replacing your ECM is a manageable job for a DIYer with basic tools. Following these steps will ensure a smooth process.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 15 minutes for the system capacitors to discharge.
- Locate the Module: Find the old ECM. On a 2009 Corvette, it’s typically located in the right-hand side of the engine compartment. For other models, refer to the fitment list for its general location (e.g., RH firewall, LH engine compartment).
- Disconnect Connectors: Carefully release the locking tabs on the electrical wiring harnesses and pull them straight out from the module. Never force them. Inspect the pins for any corrosion or damage.
- Remove the Old ECM: Unbolt the mounting hardware holding the module in place and remove it from the vehicle.
- Install the New ECM: Mount your new, pre-programmed module in the same location and secure it with the original hardware.
- Reconnect and Secure: Firmly plug the wiring harnesses back into the new ECM until the locking tabs click into place. Reconnect your vehicle’s negative battery terminal.
- Final Steps: Your vehicle may require a security relearn procedure, which can often be done without special tools (e.g., turning the key to ‘ON’ for 10-15 minutes). Consult a service manual for your specific model’s procedure if needed. Start the engine and check for proper operation.
Will This Fit My Vehicle?
This ECM is a direct 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 verify your application from the list below:
- 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): 3.7L
- Buick Lucerne (2009-2011): 4.6L
- Saab 9-7X (2009)
Frequently Asked Questions
Why do you need my VIN?
Your Vehicle Identification Number (VIN) is essential. We use it to load the exact, correct GM-certified software and calibrations for your vehicle’s specific engine, transmission, and options. This ensures perfect compatibility and performance.
Is any additional programming required after installation?
No. This module arrives pre-programmed and ready for installation. In some cases, a simple ‘security relearn’ or ‘CASE relearn’ procedure may be needed, which can typically be performed without a scan tool.
Will this fix my check engine light?
If the check engine light is caused by an internal failure of the ECM (like codes P0601-P0606), then yes, this part will resolve the issue. It’s crucial to ensure the ECM is the actual problem and not a faulty sensor or wiring issue.
Is this a brand new part?
This is a high-quality, tested replacement part guaranteed to meet or exceed original equipment performance. We ensure every module is flashed with the latest stable software from GM for maximum reliability.
How do I find my original part number?
The part number is printed on a sticker on your original ECM. You can cross-reference it with the list of interchangeable service numbers provided in this listing to confirm compatibility.