Restore Your Vehicle’s Performance and Reliability
Is your Cadillac, Corvette, or GM truck plagued by a persistent Check Engine Light, erratic performance, or a frustrating no-start condition? The Engine Control Module (ECM) is the brain of your vehicle’s powertrain, and when it fails, it can cause a cascade of problems that are often difficult to diagnose. This isn’t just an inconvenience; it affects fuel economy, emissions, and overall drivability. As a technician with over two decades of experience, I’ve seen firsthand how a failing ECM can mimic other issues, leading to wasted time and money on unnecessary repairs.
This is your direct, reliable solution. We are offering a genuine GM Engine Control Module, service part number 1263605, that arrives at your door completely programmed to your vehicle’s specific Vehicle Identification Number (VIN). This critical step ensures that the module has the latest software updates from General Motors, addressing potential bugs from the original programming and optimizing performance. By providing your VIN at checkout, you eliminate the need for an expensive trip to the dealership for programming. This is a true plug-and-play fix designed for both professional installers and dedicated DIYers.
A Technician’s Notebook: The Intermittent Stall Mystery
I once had a 2009 Corvette ZR1 in my bay with an issue that was driving the owner crazy. It would run perfectly for days, then suddenly stall at a stoplight with no warning and no immediate Check Engine Light. We checked fuel pressure, sensors, and wiring—everything seemed fine. The only clue was a stored history code, U0100 (Lost Communication With ECM/PCM). After exhausting the usual suspects, we monitored the ECM’s internal temperature and voltage data on a long test drive. We discovered the module’s processor would intermittently fail when it reached a specific operating temperature. We replaced it with a VIN-programmed module just like this one, and the problem was solved instantly. It’s a classic example of how a faulty ECM can create phantom issues that defy typical diagnostics.
Common Signs of a Failing ECM
If the central computer is failing, your vehicle will let you know. Keep an eye out for these common symptoms, which often point directly to a needed 2009 CTS Engine Module replacement or a similar GM vehicle.
- ✔ Unexplained Check Engine Light (CEL) illumination
- ✔ Stored diagnostic trouble codes (DTCs) like P0601, P0606, or P060A, indicating internal module failure
- ✔ Vehicle will not start or is very hard to start
- ✔ Poor or erratic automatic transmission shifting
- ✔ Noticeable decrease in fuel efficiency
- ✔ Engine stalling, stumbling, or misfiring for no apparent reason
- ✔ Communication errors with diagnostic scan tools
Your Straightforward Installation Guide
Replacing your ECM is a manageable job that you can do with basic hand tools. This pre-programmed module makes the process even simpler. Follow these steps for a successful installation.
- 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 ECM: The module’s location varies by model (e.g., RH front engine compartment on a CTS, lower air cleaner box on a Lucerne). Refer to the fitment list for your vehicle’s specific location.
- Disconnect and Remove: Carefully unplug the electrical connectors. Most have a locking tab or lever that needs to be released. Once disconnected, unbolt the module from its mounting bracket and remove it.
- Install the New Module: Mount your new, pre-programmed ECM securely onto the bracket. Reconnect the electrical connectors, ensuring they click firmly into place.
- Reconnect the Battery: Re-attach the negative battery terminal.
- Perform Security Relearn (If Necessary): On many GM vehicles, you will need to perform a simple key-on/key-off security relearn procedure to sync the new ECM with your vehicle’s anti-theft system. This typically involves turning the key to the ‘ON’ position for 10-15 minutes. Consult your vehicle’s service information for the exact procedure.
Verified Vehicle Compatibility
This module is a direct replacement for multiple service numbers, including 12636659, 12639300, 12628993, and more. It is confirmed to fit the following vehicles with the specified options:
• CTS (2009) 6.2L
• DTS (2009-2011)
• SRX (2009) 4.6L
• STS (2009-2010) 4.4L, 4.6L
• XLR (2009)
Chevrolet:
• Colorado (2009-2012) 2.9L, 3.7L
• Corvette (2009) ZR1
• Trailblazer (2009) 6.0L
GMC:
• Canyon (2009-2012) 2.9L, 3.7L
• Envoy (2009) 5.3L
Buick:
• Lucerne (2009-2011) 4.6L
Hummer:
• H3 (2009-2010) 3.7L
Saab:
• 9-7X (2009)
Frequently Asked Questions
Frequently Asked Questions
What exactly is VIN programming?
VIN programming means we load the module with the specific software and calibrations for your exact vehicle using its 17-digit VIN. This ensures all systems, from the engine to the transmission and anti-theft, function correctly, just as the factory intended.
Do I need to do anything after installing this ECM?
In most cases, you will only need to perform a simple security relearn procedure, which does not require any special tools. We recommend checking your vehicle’s service manual for the specific steps, but it’s typically a straightforward key-on/key-off process.
How do I provide my VIN?
Please enter your 17-digit VIN in the notes section during checkout or send it to us in a message after your purchase. We cannot program and ship your module without it.
Is this part a guaranteed fix for my problem?
While this 2009 CTS Engine Module is the definitive solution for internal ECM failure (codes P0601, etc.), it’s crucial to ensure your vehicle has been properly diagnosed. This part will not fix issues related to faulty sensors, wiring, or other mechanical components.
What if my original part number is slightly different?
This module is interchangeable with a wide range of GM service numbers, including 12636659, 12639300, 12628993, and others listed in the description. As long as your vehicle is on the compatibility list, this module will function correctly once programmed to your VIN.