Is your Cadillac STS, Corvette, or Hummer H3 suffering from perplexing engine issues? A faulty Engine Control Module (ECM) is often the culprit behind problems like poor fuel economy, intermittent stalling, or a persistent check engine light that won’t go away. The ECM is the brain of your vehicle’s engine, and when it fails, it can cause a cascade of frustrating and potentially damaging symptoms. This direct-fit Engine Control Module, part number 1263605, is the definitive solution to restore your vehicle’s performance, reliability, and drivability.
We take the guesswork and high dealership costs out of the equation. Unlike a generic module from a parts store, this unit is professionally programmed to your vehicle’s specific Vehicle Identification Number (VIN) before it ships. This crucial step ensures that the ECM has the latest software updates from General Motors and communicates flawlessly with your vehicle’s other systems, such as the transmission, anti-lock brakes, and security system. Simply provide your VIN at checkout, and we handle the complex programming for you, making installation as straightforward as possible.
Common Symptoms of a Failing ECM
- ✔ Persistent Check Engine Light (CEL) illumination
- ✔ Engine stalling or misfiring unexpectedly
- ✔ Noticeable decrease in fuel efficiency
- ✔ Rough idling or hesitation during acceleration
- ✔ Difficulty starting the engine or a complete no-start condition
- ✔ Transmission shifting problems or harsh shifts
- ✔ Unexplained loss of power
- ✔ Communication errors with diagnostic scan tools
We had a 2009 Cadillac CTS-V come in that was driving the owner crazy. It would run perfectly for days, then suddenly go into limp mode with a dozen random error codes. The local shop had replaced sensors and checked wiring for weeks with no success. After confirming the basics were solid, we suspected the ECM was failing internally, but only when it got hot. We installed one of our VIN-programmed modules, performed the security relearn, and the car ran perfectly. The owner was thrilled to have his high-performance vehicle back and running reliably. It’s a classic example of how a failing computer can mimic a wide range of other mechanical issues, making a correct diagnosis essential.
Your Pre-Programmed 2009-2010 STS Engine Module Solution
Choosing the right replacement part is critical for a lasting repair. This module is not just a component; it’s a complete solution designed for your specific GM vehicle. By programming it with the latest factory software matched to your VIN, we ensure compatibility and optimal performance right out of the box. This eliminates the need for expensive programming tools or a trip to the dealership after installation. This module is a direct replacement for a wide range of service numbers, ensuring broad compatibility across numerous GM models and years.
Guaranteed Fitment for Your Vehicle
This Engine Control Module is a direct replacement for part number 1263605 and is interchangeable with the following service numbers: 12636659, 12639300, 12628993, 12628911, 12625453, 12622175, 12630464, and 12678512. It is confirmed to fit the following vehicles:
- Cadillac CTS (2009)
- Cadillac DTS (2009-2011)
- Cadillac SRX (2009)
- Cadillac STS (2009-2010)
- Cadillac XLR (2009)
- Chevrolet Colorado (2009-2012)
- Chevrolet Corvette (2009)
- Chevrolet Trailblazer (2009)
- GMC Canyon (2009-2012)
- GMC Envoy (2009)
- Hummer H3 (2009-2010)
- Buick Lucerne (2009-2011)
- Saab 9-7x (2009)
Please verify your vehicle’s specific options and original part number to ensure a perfect match.
Installation and Post-Installation Requirements
While this module is delivered ready to install, many GM vehicles require a security relearn procedure after the ECM is replaced. This is a standard anti-theft measure that syncs the new module with your vehicle’s keys and ignition system. This procedure, often called a “CASE Relearn” or “Key Relearn,” can typically be performed without special tools and involves a sequence of key turns. Instructions for this process are widely available online for your specific model, or your local mechanic can perform it quickly.
Frequently Asked Questions
Why do you need my VIN?
Your Vehicle Identification Number (VIN) is essential for us to load the correct, vehicle-specific software from GM. This ensures the module controls your engine, transmission, and emissions systems exactly as the factory intended, preventing compatibility issues.
Is this a plug-and-play part?
Yes, the module is physically plug-and-play. However, after installation, you will likely need to perform a security relearn procedure to sync the new module with your vehicle’s anti-theft system. This is a standard step for most GM ECM replacements.
How do I know if my ECM is actually the problem?
While the symptoms listed are strong indicators, a definitive diagnosis should be made by a qualified technician. They can rule out other potential issues like faulty sensors, wiring problems, or fuel delivery issues before you replace the ECM.
Will this fix my check engine light?
If the check engine light is caused by an internal failure of your old ECM, then yes, this replacement module will resolve the issue. If the light is on due to another faulty component (like an oxygen sensor), that component will still need to be addressed.
What tools are needed for installation?
Installation typically requires basic hand tools, such as a socket set and ratchet, to disconnect the battery and unbolt the module. No special programming tools are required on your end since we handle the programming before shipping.