Restore Your Vehicle’s Brain and End Frustrating Engine Problems
Is your Corvette, CTS-V, or Trailblazer acting possessed? Unexplained stalling, a persistent Check Engine Light, and erratic engine behavior can often be traced back to one component: a failing Engine Control Module (ECM). As a technician with over two decades of experience under the hood, I’ve seen firsthand how a faulty ECM can turn a reliable vehicle into a source of constant headaches. This isn’t just a part; it’s the central computer responsible for engine performance, fuel economy, and emissions. When it fails, everything downstream is affected.
This replacement Engine Control Module, part number 12636659, is the definitive solution to get your vehicle running right again. The biggest hurdle with ECM replacement has always been the expensive and time-consuming trip to the dealership for programming. We eliminate that step entirely. Simply provide your vehicle’s VIN at checkout, and our experts will program this module with the latest GM factory software specific to your car. It arrives at your door ready for a straightforward installation, saving you time, money, and the typical dealership hassle. This is the most direct path to restoring your engine’s original performance and reliability.
From the Diagnostic Bay
I remember a 2009 Corvette ZR1 that came into my shop with a ghost of a problem. The owner complained of intermittent no-starts and a random stalling issue that no one could pin down. The car would run perfectly for a week, then refuse to start for an hour. We checked fuel pressure, spark, and battery—all perfect. Scan tools showed intermittent U0100 (Lost Communication With ECM) codes. After hours of chasing wires, we swapped in a known-good test ECM. The problems vanished instantly. The original module had an internal hairline fracture that would separate when it heated up, breaking communication. A replacement, pre-programmed 2009 Corvette ECM like this one was the permanent, reliable fix.
Is Your Vehicle Showing These Telltale ECM Failure Signs?
- ✔ Check Engine Light is on with codes like P0601, P0606, or P060A (Internal Control Module Processor/Memory Error).
- ✔ Your engine cranks but refuses to start for no apparent reason.
- ✔ Unexplained drops in fuel economy and poor engine performance.
- ✔ Stalling, rough idling, or engine hesitation during acceleration.
- ✔ Automatic transmission shifting erratically or harshly.
- ✔ Communication errors (U-codes) with other vehicle modules.
- ✔ The cooling fans run constantly, even when the engine is cold.
A Straightforward Guide to Installation
- ✔ Safety First: Always disconnect the negative terminal from your vehicle’s battery before beginning any electrical work.
- ✔ Locate the ECM: On a 2009 Corvette ECM, it’s typically found in the right-hand side of the engine compartment. For other models, refer to the fitment list for common locations (e.g., RH firewall, LH engine).
- ✔ Disconnect Connectors: Carefully release the locking tabs on the wiring harness connectors and pull them straight out from the old module. 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 to reuse it.
- ✔ Install the New Module: Mount your new, pre-programmed ECM securely onto the bracket.
- ✔ Reconnect Everything: Firmly press the wiring harness connectors into the new module until they click and the locking tabs are secure. Reconnect the negative battery terminal.
- ✔ Perform Relearn (If Necessary): While we handle the main programming, some vehicles require a security or crank-sensor relearn procedure. This can often be done without special tools (consult your vehicle’s service manual) or by a local shop.
Verified Vehicle Compatibility
This module is a direct replacement for a wide range of GM vehicles and is interchangeable with service numbers 12639300, 1263605, 12628993, 12628911, 12625453, 12622175, 12630464, and 12678512. Please confirm your model and options 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
Do I need to do any programming myself?
No. We program the module to your specific vehicle using the VIN you provide during checkout. It arrives ready to be installed. In some cases, a simple security relearn procedure may be needed after installation.
What information do you need from me?
We require your 17-digit Vehicle Identification Number (VIN) to ensure the module is programmed with the correct, most current software for your vehicle’s specific configuration.
Is this a direct replacement for my original ECM?
Yes, this is a direct-fit replacement for the original equipment module and interchanges with multiple service numbers, including the primary part number 12636659.
What if my part number isn’t listed but my vehicle is?
Please contact us with your VIN. GM uses many interchangeable part numbers, and we can verify compatibility for you to ensure you get the correct part for your vehicle.
Will this fix my Check Engine Light?
If the Check Engine Light is caused by an internal failure of the ECM (e.g., codes P0601-P0606), then this replacement module is the correct solution. Always ensure proper diagnosis has been performed to rule out other sensor or wiring issues.