Is Your Sierra 1500 Acting Up? Let’s Get It Fixed.
As a technician with over two decades in the bay, I’ve seen it all when it comes to modern truck electronics. If your 2014-2016 Sierra or Silverado is suddenly giving you headaches—like cranking but not starting, a check engine light that won’t go away, erratic shifting, or just plain poor performance—the Engine Control Module (ECM) is one of the first places a seasoned pro will look. It’s the brain of your entire powertrain, and when it starts to fail, the symptoms can be confusing and frustrating.
The ECM lives in a tough environment, bolted to the engine compartment, where it endures constant vibration and extreme heat cycles. Over years and thousands of miles, this can lead to internal failures of the circuit board or processors. The result? A truck that’s unreliable at best and a driveway ornament at worst.
From the Shop Floor: A Real-World Diagnosis
“A customer’s 2015 Sierra 1500 came in last week with these exact symptoms. It would crank strong all day but wouldn’t fire up. We checked for fuel pressure and spark at the plugs—both were present. The confusing part was the scan tool; it kept giving us a ‘No Communication with ECM’ error (DTC U0100). After verifying the power and ground wires to the module were good, we knew we had a failed ECM. It was internally shorted, preventing the rest of the truck’s modules from talking to it and stopping the fuel injectors from firing. This is a classic failure mode I’ve diagnosed on hundreds of these GM trucks.”
The Right Solution: A Pre-Programmed, Ready-to-Install ECM
Replacing the ECM used to mean a trip to the dealership for expensive programming. Not anymore. This genuine GM Engine Control Module is the direct, hassle-free solution. We take the complexity out of the repair by programming the module specifically for your truck before we ship it to you. All we need is your Vehicle Identification Number (VIN) at checkout.
This isn’t just a convenience—it’s critical for your truck’s operation. The programming ensures the ECM has the correct software and calibrations for your specific engine, transmission, and emissions equipment. It’s loaded with the latest updates from GM, which often address factory bugs and improve performance and longevity.
Common Symptoms of a Failing GM ECM:
- ✔ Check Engine Light with various communication or sensor codes
- ✔ Vehicle cranks but will not start
- ✔ Engine stalls intermittently while driving
- ✔ Noticeable drop in fuel economy
- ✔ Harsh or erratic automatic transmission shifting
- ✔ Communication errors with a scan tool (e.g., U0100)
- ✔ False warnings for other systems on the dash
Installation Made Simple
For a Sierra or Silverado, the ECM is typically located on the driver’s side front of the engine compartment. The physical swap is straightforward: disconnect the battery, unplug the electrical connectors, unbolt the old module, and bolt the new one in its place. Once installed, you will need to perform a simple security relearn procedure (often called a Passlock or anti-theft relearn), which pairs the new ECM to your keys. This procedure can be done without any special tools and instructions are readily available online or in service manuals.
Guaranteed Fitment & Compatibility
This module, part number 12662034, is a direct replacement for a wide range of GM vehicles. Please verify your part number or match your vehicle in the list below to ensure compatibility. This module is interchangeable with the following part numbers: 12692067, 12676230, 12656993, 12672537, 12673195, 12663391, 12672963, and 12669318.
This ECM fits the following vehicles:
- ✔ Cadillac ATS: 2014-2016
- ✔ Cadillac CTS: 2014-2016
- ✔ Cadillac Escalade / ESV: 2015-2016
- ✔ Cadillac XTS: 2014-2016
- ✔ Chevrolet Camaro: 2016 (6.2L)
- ✔ Chevrolet Colorado: 2015-2016 (3.6L)
- ✔ Chevrolet Corvette: 2014-2016
- ✔ Chevrolet Silverado 1500: 2014-2016
- ✔ Chevrolet Suburban 1500: 2015-2016
- ✔ Chevrolet Tahoe: 2015-2016
- ✔ GMC Canyon: 2015-2016 (3.6L)
- ✔ GMC Sierra 1500 / Denali 1500: 2014-2016
- ✔ GMC Yukon / Yukon XL 1500: 2015-2016
Don’t let a faulty computer keep your truck down. Order this pre-programmed ECM today and restore the performance and reliability you depend on.