Programmed 2012-2016 Silverado 3500 ECM 12668991 | VIN Matched & Ready

Restore Your Truck’s Brain, Not Just a Part

As a technician with over two decades of wrenching on everything from compacts to heavy-duty trucks, I know the frustration of a vehicle that just won’t run right. When your 2012-2016 Silverado 3500 starts acting up—stalling at lights, getting terrible gas mileage, or throwing a check engine light that won’t go away—it’s easy to start throwing parts at it. But often, the problem lies deep within the vehicle’s central nervous system: the Engine Control Module (ECM).

This isn’t just another replacement part. This is a complete, ready-to-install solution. We are providing a genuine GM Engine Control Module, part number 12668991, that comes professionally programmed to your truck’s specific Vehicle Identification Number (VIN). This crucial step ensures that all systems, from the transmission to the anti-theft security, communicate perfectly from the moment you plug it in. You get the latest factory software updates from GM, which often resolve underlying drivability issues the original programming might have had. This is the fix that gets your workhorse back on the job, without the expensive trip to the dealership for programming.

Is Your Truck Showing These Signs of a Failing ECM?

A faulty ECM can cause a wide range of confusing symptoms. If you’re experiencing any of the following, the ECM is a very likely culprit, especially if you’ve already ruled out more common mechanical issues.

• ✔ The engine cranks but refuses to start.
• ✔ Persistent Check Engine Light, often with codes like P0601, P0602, P0606, or other U-series communication codes.
• ✔ A noticeable drop in fuel economy for no apparent reason.
• ✔ The engine stalls unexpectedly, either while driving or at idle.
• ✔ Rough idling, misfires, or hesitation during acceleration.
• ✔ Automatic transmission shifts harshly or at the wrong times.
• ✔ Your scan tool cannot communicate with the engine computer.

A Straightforward Guide to Your ECM Installation

Replacing the ECM on your Silverado or Sierra HD is a job most DIYers can handle with basic hand tools. The key is to be patient and follow the steps carefully. This pre-programmed module makes the electronic side of the job incredibly simple.

1. Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 15 minutes for the system capacitors to discharge before starting work.
2. Locate the Module: On the 2012-2016 Silverado 3500, the ECM is typically located in the engine compartment on the driver’s side, near the firewall or inner fender.
3. Disconnect the Harnesses: Carefully release the locking tabs on the large electrical connectors and pull them straight out from the module. Do not force them. Inspect the pins for any corrosion or damage.
4. Remove the Old ECM: Unbolt the mounting hardware holding the old module in place and remove it from the vehicle.
5. Install the New ECM: Mount your new, pre-programmed ECM in the same location. Securely reconnect the electrical harnesses until they click into place.
6. Final Steps: Reconnect the negative battery terminal. The vehicle may need to complete an idle-relearn or security-relearn procedure, which typically involves turning the key to the ‘ON’ position for 10-15 minutes before starting. Consult your owner’s manual for specific details.

Verified Compatibility for Your GM Vehicle

While this is a direct-fit solution for the 2012-2016 Silverado 3500 ECM with the 6.0L engine, this versatile module is also the correct component for a wide array of other GM vehicles. Please verify your part number or match your vehicle from the list below. This module is a direct replacement for part numbers: 12668866, 12668994, 12643636, 12663405, 12670335, 22819494, and 12692200.

• ✔ Chevrolet Silverado 2500/3500 Pickup (2012-2016) – 6.0L
• ✔ GMC Sierra 2500/3500 & Denali (2012-2016) – 6.0L
• ✔ Chevrolet Express 2500/3500 Van (2016) – 4.8L, 6.0L
• ✔ GMC Savana 2500/3500 Van (2016) – 4.8L, 6.0L
• ✔ Chevrolet Suburban 3500 (2016)
• ✔ Chevrolet Cruze (2012-2016) – Various engines, check IDs
• ✔ Chevrolet Sonic (2012-2016) – Various engines, check IDs
• ✔ Chevrolet Trax (2013-2016)
• ✔ Chevrolet Volt (2011-2015)
• ✔ Chevrolet Spark (2014-2015) – Gasoline model
• ✔ Buick Encore (2013-2016) – 1.4L
• ✔ Cadillac ELR (2014-2016)