2012-2016 Sierra Denali 3500 ECM 12668866 Programmed to Your VIN

Is Your Sierra Denali Running Rough or Not Starting?

If you’re dealing with a persistent check engine light, erratic engine behavior, poor fuel economy, or a frustrating no-start condition, the problem often points directly to a failing Engine Control Module (ECM). As the central computer of your truck, the ECM is responsible for managing everything from fuel injection and ignition timing to transmission shifting and emissions. When it fails, your powerful Sierra Denali can feel more like a paperweight. In my 20+ years as a technician, I’ve seen countless trucks sidelined by faulty ECMs, often due to years of exposure to engine bay heat and vibration.

The Dealership-Free Solution: A Plug-and-Play ECM

Forget about towing your truck to the dealership and paying hundreds in diagnostic and programming fees. This Engine Control Module is the straightforward, reliable fix you need. We take all the hassle out of the process. Simply provide us with your vehicle’s VIN (Vehicle Identification Number) during checkout, and our experts will program the module with the latest, most stable GM factory software specific to your 2012-2016 Sierra Denali 3500 ECM. It arrives at your door ready for installation—no extra steps required.

Key Benefits of Our Programmed ECM:

• ✔ VIN-Programmed for Your Truck: We flash the module with your vehicle’s specific software using your VIN, ensuring perfect compatibility.
• ✔ Eliminates Dealer Programming: This unit is 100% plug-and-play. No need for expensive scan tools or a trip to the dealership.
• ✔ Solves Common Issues: Corrects problems like check engine lights (CEL), false sensor codes, rough running, poor shifting, and no-start conditions related to the ECM.
• ✔ Latest GM Software: Your module comes loaded with the newest factory updates, which can improve performance and efficiency over the original software.
• ✔ Direct-Fit Replacement: Guaranteed to fit and function just like the original, restoring your truck’s reliability.

Simple Installation Guide: Get Back on the Road Fast

Installing your new 2012-2016 Sierra Denali 3500 ECM is a job most DIYers can handle in under 30 minutes with basic tools. It’s typically located on the driver’s side of the front engine compartment.

1. Safety First: Disconnect the negative terminal from your truck’s battery.
2. Locate the ECM: Find the module on the LH front side of the engine bay.
3. Disconnect Connectors: Carefully unclip the wiring harness connectors. Inspect the pins for any corrosion or damage before connecting to the new module.
4. Remove the Old Module: Unbolt the old ECM from its mounting bracket.
5. Install the New Module: Bolt the new ECM in place and securely reconnect the wiring harnesses.
6. Reconnect Battery: Reattach the negative battery terminal. The vehicle may require a security relearn procedure, which can typically be done by cycling the key.

Guaranteed Compatibility

This module is a direct replacement for a wide range of GM vehicles and part numbers. Please verify your original part number or match your vehicle in the list below. This ECM is compatible with the following part numbers:

12668866, 12668994, 12643636, 12663405, 12670335, 22819494, 12692200