Restore Your Truck’s Core Performance and Reliability
Is your 2015-2016 Chevrolet Colorado or other GM vehicle acting up? If you’re dealing with a persistent check engine light, erratic engine behavior, stalling, or a frustrating no-start condition, the root cause is often a failing Engine Control Module (ECM). As the ‘brain’ of your vehicle, a faulty ECM can disrupt everything from fuel delivery to transmission shifting. This isn’t just an inconvenience; it can affect fuel economy, emissions, and overall drivability. This replacement ECM is your direct-fit, reliable solution to get your vehicle running like new again.
We take the guesswork and high dealership costs out of the equation. Each module is professionally programmed with the latest GM-certified software, specifically matched to your vehicle’s VIN. This means it arrives at your door ready for installation, with no need for an expensive trip to the dealer for programming. This is the same process I’ve used in my shop for years to ensure a fast and effective repair.
A Technician’s Notebook: The Intermittent Stall
A customer brought in a 2015 GMC Canyon 3.6L with a problem that was driving him crazy: intermittent stalling at stoplights and a random no-start in the morning. There were no consistent trouble codes, just a history of U0100 (Lost Communication with ECM) and a P0601 (Internal Control Module Memory Check Sum Error) that would pop up occasionally. We checked all the basics—battery, grounds, and wiring harnesses—and everything looked solid. After spending hours chasing phantom electrical gremlins, experience pointed to an internal ECM failure. The processor was intermittently failing under certain temperature conditions. We installed a VIN-programmed ECM, performed the security relearn, and the truck has been running perfectly ever since. This simple swap saved the customer from potentially replacing dozens of other parts in a frustrating guessing game.
Is Your Vehicle Showing These Symptoms?
A failing ECM can manifest in many ways. If you’re experiencing any of the following, it’s a strong indicator that your engine computer needs attention. In my 20+ years of experience, these are the most common signs:
- ✔ Check Engine Light is illuminated with communication codes (U-codes) or internal processor codes (P0601, P0602, P0606).
- ✔ Vehicle will not start or is very difficult to start.
- ✔ Noticeable decrease in fuel efficiency.
- ✔ Engine stalling, sputtering, or misfiring for no apparent reason.
- ✔ Poor or hesitant acceleration.
- ✔ Automatic transmission shifting erratically or harshly.
- ✔ Failure to pass state emissions testing.
A Straightforward Guide to Installation
Installing your new 2015-2016 Colorado ECM is a manageable job for a confident DIYer. While a security relearn procedure is required after installation (a simple process that does not require special tools), the physical swap is straightforward. Always consult a vehicle-specific repair manual if you are unsure.
- Safety First: Disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent accidental reconnection.
- Locate the ECM: On the 2015-2016 Colorado/Canyon, the ECM is typically located on the right-hand (passenger side) firewall in the engine bay. On other GM trucks like the Silverado/Sierra, it’s often in the left-front of the engine compartment.
- Disconnect Connectors: Carefully release the locking tabs and unplug the main electrical harness connectors from the old module. Inspect the connectors for any corrosion or damage.
- Remove the Old Module: Unbolt the old ECM from its mounting bracket. Keep the hardware, as you will need it to install the new unit.
- Install the New Module: Mount your new, pre-programmed ECM onto the bracket and secure it with the original hardware.
- Reconnect Everything: Plug the electrical connectors firmly into the new module until they click into place. Reconnect the negative battery terminal.
- Perform Security Relearn: You will need to perform the vehicle’s anti-theft security relearn procedure. This typically involves a sequence of turning the key to the ‘ON’ position for 10-15 minutes, then ‘OFF’, repeated three times. This allows the new ECM to sync with your vehicle’s security system.
Guaranteed Vehicle Compatibility
This module is a direct replacement for part number 12663391 and is compatible with several other service numbers. We have verified its fitment across a wide range of GM vehicles. Please confirm your model and options below:
Fits Models Including:
• Chevrolet Colorado (2015-2016) – 3.6L, (RH firewall)
• GMC Canyon (2015-2016) – 3.6L, (RH firewall)
• Chevrolet Silverado 1500 (2014-2016) – (LH front engine compartment)
• GMC Sierra 1500 / Denali 1500 (2014-2016) – (LH front engine compartment)
• Cadillac ATS (2014-2016) – 3.6L
• Cadillac CTS (2014-2016) – 3.6L, 6.2L
• Cadillac Escalade / ESV (2015-2016) – (LH front engine compartment)
• Chevrolet Corvette (2014-2016) – (RH cowl under dash)
• Chevrolet Camaro (2016) – 6.2L
• Chevrolet Tahoe / Suburban 1500 (2015-2016) – (LH front engine compartment)
• GMC Yukon / Yukon XL 1500 (2015-2016) – (LH front engine compartment)
• Cadillac XTS (2014-2016) – 3.6L (VIN 8, opt LF3)
Note: Some models may have specific ID requirements. Please match your part number or contact us with your VIN to ensure 100% compatibility.
Frequently Asked Questions
How does the VIN programming work?
After you place your order, you simply provide us with your vehicle’s 17-digit VIN. We use this number to access the latest official GM software for your specific vehicle configuration and flash it onto the module before shipping.
Do I need special tools for the security relearn?
No. For most compatible GM vehicles, the security relearn procedure does not require any special scan tools. It’s a simple key-cycle process that you can do in your driveway. We can provide instructions if needed.
Is this a plug-and-play part?
Yes, because we program it to your VIN, it is a plug-and-play solution. Once you install it and complete the security relearn, your vehicle should start and run correctly without any additional programming.
Will this fix my specific problem?
This module will correct issues directly caused by a failing ECM, such as internal processor faults or software corruption. While it solves many common problems, it’s essential to ensure your vehicle has been properly diagnosed. It will not fix issues related to other faulty sensors or wiring problems.
How do I find my original part number?
The part number is printed on a sticker on your original ECM. You can compare it to the list of compatible part numbers on this page to help confirm fitment. However, providing your VIN is the most accurate way to guarantee compatibility.