Restore Your Cadillac’s Brainpower and Performance
Is your 2009-2011 Cadillac DTS running erratically, stalling, or refusing to start? Are you battling a persistent Check Engine Light that just won’t go away? You’re likely dealing with a failing Engine Control Module (ECM), the central computer of your vehicle. In my two decades as a technician, I’ve seen firsthand how a faulty ECM can cause a cascade of frustrating and hard-to-diagnose problems. This isn’t just a part; it’s the solution to getting your vehicle back to the smooth, reliable performance you expect.
We take the guesswork and hassle out of the repair. This genuine GM ECM, part number 12678512, arrives at your door pre-programmed to your specific vehicle. Simply provide us with your Vehicle Identification Number (VIN) during checkout, and our experts will flash the module with the latest, most stable software updates directly from GM. This means no expensive trips to the dealership for programming and no need for specialized scan tools. It’s a direct-fit, ready-to-install solution that saves you time and money.
From the Diagnostic Bay: The Ghost in the Machine
A customer brought in a 2010 Cadillac STS with a perplexing issue: intermittent stalling at traffic lights and a random no-start condition that would vanish as mysteriously as it appeared. The codes were all over the place—U0100 for lost communication, P0300 for random misfires, and occasionally a P0601 for an internal module error. We checked everything: wiring, fuel pressure, sensors. Everything tested fine. After hours of chasing ghosts, we focused on the ECM. On the surface, it looked fine, but under load and heat, the internal processor was failing intermittently. Swapping in a pre-programmed ECM like this one solved every single issue instantly. It’s a reminder that sometimes the most complex problems have a straightforward, central cause.
Common Signs of a Failing Engine Computer
If your vehicle is experiencing any of the following, a faulty ECM is a very likely culprit. Replacing your 2009-2011 DTS ECM can be the definitive fix.
- ✔ Check Engine Light is on with codes like P0601, P0606, or other communication errors (U-codes).
- ✔ Engine cranks but refuses to start.
- ✔ Unexplained stalling or rough idling.
- ✔ Noticeable decrease in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ The cooling fans run constantly, even when the engine is cold.
- ✔ Failure to pass an emissions test.
A Straightforward Guide to Installation
Installing your new ECM is a manageable job for a confident DIYer. Follow these steps carefully to 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 ECM: On the 2009-2011 Cadillac DTS, the Engine Control Module is typically located in the engine bay. Consult your vehicle’s service manual for the exact position.
- Disconnect Connectors: Carefully release the locking tabs on the wiring harness connectors and pull them straight out from the module. Never force them. Inspect the connectors for any corrosion or damage.
- Remove the Old Module: Unbolt the old ECM from its mounting bracket. Keep the mounting hardware, as you will need it for the new module.
- Install the New ECM: Mount your new, pre-programmed ECM onto the bracket and secure it with the original hardware.
- Reconnect and Secure: Firmly plug the wiring harnesses back into the new module until they click into place. Reconnect your vehicle’s negative battery terminal.
- Perform Security Relearn: Most GM vehicles require a 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. Please refer to our included instructions or your service manual for the specific procedure for your vehicle.
Verified Vehicle Compatibility
This ECM is a direct replacement for service number 12678512 and is interchangeable with part numbers 12636659, 12639300, 1263605, 12628993, 12628911, 12625453, 12622175, and 12630464. It is guaranteed to fit the following vehicles:
- CADILLAC CTS 2009 (6.2L)
- CADILLAC DTS 2009-2011
- CADILLAC SRX 2009 (4.6L)
- CADILLAC STS 2009 (4.4L, 4.6L)
- CADILLAC STS 2010 (4.6L)
- CADILLAC XLR 2009
- BUICK LUCERNE 2009-2011 (4.6L)
- 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)
- SAAB 9-7X 2009
This 2009-2011 DTS ECM is the reliable heart of your vehicle’s engine management system. Order today to restore its health and your peace of mind.
Do I need to do any programming myself?
Do I need to do any programming myself?
No. We handle all the programming for you before shipment. Just provide your VIN at checkout, and the module will arrive ready to install with the latest GM software for your specific vehicle.
Why do you need my VIN?
The VIN (Vehicle Identification Number) is essential for us to load the correct software and calibrations for your car’s specific engine, transmission, and factory options. This ensures perfect compatibility and performance.
Is this a simple plug-and-play installation?
Mostly, yes. After the physical installation, you will need to perform a simple security relearn procedure, which syncs the new ECM to your car’s anti-theft system. This usually takes about 10-15 minutes and does not require any special tools. Instructions are provided.
Will this fix my car’s specific problem?
This ECM is the correct solution for issues caused by a failed internal module, such as specific diagnostic trouble codes (P0601, P0606), no-start conditions, and erratic engine behavior. While it resolves many common problems, always ensure your vehicle has been properly diagnosed by a qualified mechanic.