Restore Peak Performance to Your Vehicle with a VIN-Programmed ECM
Is your Cadillac, Chevy, or GM vehicle suffering from frustrating issues like a persistent check engine light, erratic engine behavior, stalling, or a complete no-start condition? These are classic signs of a failing Engine Control Module (ECM), the central computer of your vehicle. Don’t let a faulty module keep you off the road. This direct-fit replacement ECM, part number 12678512, is the reliable, professional-grade solution to restore your vehicle’s factory performance and dependability.
As a technician with over two decades of experience, I’ve seen firsthand how a failing ECM can cause a cascade of confusing problems. The most significant advantage of this module is our complimentary VIN programming service. Before we ship your part, we flash it with the latest, most stable software updates directly from GM, tailored specifically to your vehicle’s Vehicle Identification Number (VIN). This means you receive a part that’s ready for installation, saving you hundreds of dollars and the hassle of a dealership visit for programming. This is the same process we use in our own repair facility to ensure a successful and lasting repair.
A Technician’s Notebook: The Ghost in the Machine
I remember a 2009 Cadillac SRX that came into the shop with a list of symptoms that made no sense together. The transmission was shifting harshly, the cooling fans would run constantly, and it had random misfire codes that would come and go. The owner had already replaced spark plugs and a coil pack with no success. After hooking up the scan tool, I noticed communication errors with multiple modules (U-codes). This is a huge red flag. Instead of chasing individual symptoms, we focused on the network’s hub: the ECM. A faulty ECM can send corrupt data, causing other modules to act erratically. We installed a VIN-programmed 2009 SRX Engine Control Module, performed the security relearn, and all the ghost-like issues vanished instantly. It’s a perfect example of how a single component can be the root of many problems.
Common Signs of a Failing ECM
- ✔ Check Engine Light is on with codes like P0601, P0602, P0606 (Internal Controller Failure) or U0100 (Lost Communication With ECM/PCM).
- ✔ Engine cranks but will not start.
- ✔ Poor fuel economy and engine performance.
- ✔ Intermittent stalling or rough idling.
- ✔ Automatic transmission shifting problems.
- ✔ Seemingly unrelated error codes appearing for various sensors.
A Straightforward Guide to Installation
- ✔ Safety First: Disconnect the negative terminal from your vehicle’s battery and wait at least 10 minutes to allow all capacitors to discharge.
- ✔ Locate the ECM: On the 2009 SRX, the ECM is typically found in the engine compartment on the driver’s side. Consult a repair manual for your specific vehicle if you’re unsure.
- ✔ Disconnect and Remove: Carefully unplug the wiring harness connectors. They have locking tabs that must be released. Then, unbolt the old module from its mounting bracket.
- ✔ Install the New Module: Bolt the new ECM securely into place. Reconnect the wiring harness connectors, ensuring they click and lock firmly.
- ✔ Reconnect Battery: Reattach the negative battery terminal.
- ✔ Perform Security Relearn (CRITICAL): You must perform a security relearn procedure. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then ‘OFF’ for 10 seconds, and repeating this cycle three times. This allows your vehicle’s anti-theft system to recognize the new ECM. Your vehicle will not start until this is completed.
Verified Vehicle Compatibility
This module is a direct replacement for service number 12678512 and is interchangeable with 12636659, 12639300, 1263605, 12628993, 12628911, 12625453, 12622175, and 12630464. It fits a wide range of GM vehicles, including:
- 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)
- 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
What does ‘VIN Programmed’ mean?
It means we load the module with your vehicle’s specific software using your VIN before shipping. This ensures it communicates correctly with your car’s systems, just like a new part from the dealership, but without the extra cost and trip.
Do I need to do anything after I install it?
Yes. After installation, you must perform the vehicle’s Security Relearn Procedure. This is a simple process that syncs the new ECM to your car’s anti-theft system and is required for the engine to start. Instructions are included above.
Will this fix my check engine light?
If the check engine light is caused by a faulty ECM (common codes P0601-P0606), then yes, this part is the correct fix. However, you should always confirm the diagnosis, as other failing parts can also trigger a check engine light.
How do I provide my VIN?
Simply enter your 17-digit VIN in the designated box on the checkout page or send it to us in a message after your purchase. We cannot program and ship the module without it.
Is this part difficult for a DIYer to install?
The physical replacement is straightforward for most DIYers with basic tools. The most important step is performing the security relearn correctly. As long as you follow the steps, it’s a very manageable job.