If you’re dealing with frustrating, hard-to-diagnose issues on your Cadillac, Chevy, or GMC, the Engine Control Module (ECM) is often the culprit. As a technician with over two decades of experience, I’ve seen firsthand how a failing ECM can cause everything from a no-start condition to random stalling and a dashboard lit up with warning lights. This isn’t just an inconvenience; it’s a critical failure that sidelines your vehicle. This listing is for a direct-fit, reliable solution: a replacement ECM, part number 12678513, that arrives at your door pre-programmed and ready for installation.
The biggest hurdle with ECM replacement has always been the expensive and time-consuming programming required at a dealership. We eliminate that step entirely. Simply provide us with your vehicle’s VIN (Vehicle Identification Number) during checkout, and our experts will flash this module with the latest, most stable GM factory software specific to your car or truck. This ensures that when you receive your 2010-2015 CTS ECM, it’s truly a plug-and-play component, restoring communication between all your vehicle’s vital systems.
Is Your GM Vehicle Showing These Symptoms?
A failing engine computer can manifest in numerous ways. If you’re experiencing any of the following, a faulty ECM is a likely cause:
- âś” Check Engine Light is on with internal processor fault codes (e.g., P0601, P0606).
- âś” Vehicle refuses to start or cranks but won’t fire up.
- âś” Intermittent stalling, especially after the engine has warmed up.
- âś” Noticeable decrease in fuel economy and poor engine performance.
- âś” Communication errors with other modules (U-codes).
- âś” Problems with automatic transmission shifting.
From the Diagnostic Bay: The Ghost in the Machine
I remember a 2013 CTS-V that came into the shop with a maddeningly intermittent issue. The owner said it would run perfectly for days, then suddenly lose power and stall at a stoplight, only to start right back up. There were no consistent trouble codes, just a history of random communication faults. We checked wiring, grounds, and power feeds for hours. Finally, while monitoring live data, I saw the 5-volt reference signal flicker and drop out for a split second—just before the engine died. That pointed directly to an internal failure in the ECM. We installed a pre-programmed module just like this one, and the ‘ghost’ was gone. The car ran flawlessly, and the customer was thrilled to have his high-performance vehicle back and reliable.
A Straightforward Guide to Installation
Installing your new 2010-2015 CTS ECM is a manageable job for a DIY enthusiast. While locations vary slightly by model, the general process is similar. Always consult a service manual for your specific vehicle.
- Safety First: Disconnect the negative terminal from your vehicle’s battery and wait at least 15 minutes to allow all modules to power down completely.
- Locate the ECM: On many of these vehicles (CTS, Camaro, Corvette), it’s found in the engine compartment, often on the right-hand (passenger) side. On trucks like the Colorado/Canyon, it’s typically on the right-hand side of the firewall.
- 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. There are usually a few 10mm bolts holding it in place.
- Install the New Module: Mount your new, pre-programmed ECM in place and tighten the bolts. Reconnect the wiring harnesses, ensuring they click securely into place.
- Reconnect Battery & Perform Relearn: Reconnect the negative battery terminal. The final step is often a security relearn procedure (sometimes called a Passlock or anti-theft relearn), which typically involves turning the key to the ‘ON’ position for 10-15 minutes. This allows your vehicle’s anti-theft system to recognize the new ECM.
Verified Vehicle Compatibility
This module is a direct replacement for service numbers 12678513 and 12633264. Please verify your part number or match your vehicle from the list below to ensure proper fitment.
- Cadillac CTS: 2010-2013 (6.2L), 2014 (Sdn, Cpe, SW, 6.2L), 2015 (Cpe)
- Chevrolet Camaro: 2012 (3.6L & 6.2L, ID 12633264), 2013-2015 (6.2L, VIN P, opt LSA)
- Chevrolet Corvette: 2010-2013 (6.2L, VIN R or T, opt LS9)
- Chevrolet Colorado: 2010-2012 (5.3L)
- Chevrolet Malibu: 2010-2012 (3.6L)
- GMC Canyon: 2010-2012 (5.3L)
- Hummer H3: 2010 (5.3L)