Is Your Sierra 1500 Plagued by Engine Problems?
If you’re dealing with a persistent check engine light, erratic engine behavior, a no-start condition, or frustrating communication error codes, the root cause is often a failing Engine Control Module (ECM). As the central computer for your truck’s powertrain, a faulty ECM can create a cascade of problems that are difficult to diagnose. In my 20+ years as a technician, I’ve seen countless hours and dollars wasted chasing sensor and wiring issues when the ECM itself was the culprit.
The Direct Solution: A VIN-Programmed ECM
This isn’t just a replacement part; it’s a complete solution. We take a genuine GM Engine Control Module and program it specifically to your truck’s Vehicle Identification Number (VIN). This critical step ensures all factory settings are correct for your specific engine, transmission, and emissions equipment. We also load the latest, most stable software updates from General Motors, which often correct drivability issues and improve efficiency beyond what your original module offered.
Expert Pro Tip: Check Your Connectors First
Before you even unbolt the old ECM, take a moment to carefully inspect the large electrical connectors that plug into it. Over the years, I’ve seen moisture intrusion lead to green, fuzzy corrosion on the pins, and sometimes pins get bent during previous repairs. A poor connection can mimic a failed ECM and can damage your new module upon installation. Clean any corrosion with a dedicated electronics cleaner and a small brush, and ensure all pins are straight before plugging in your new part.
Symptoms of a Failing 2016-2018 Sierra 1500 ECM
A failing engine computer can manifest in numerous ways. If you’re experiencing any of the following, this module is the likely fix:
- โ Persistent Check Engine Light (CEL) with various communication or processor codes.
- โ Vehicle refuses to start or cranks but won’t fire up.
- โ Stalling, hesitation, or rough idling for no apparent reason.
- โ Noticeable decrease in fuel economy.
- โ Transmission shifting erratically or going into limp mode.
- โ Inability for scan tools to communicate with the engine computer.
Installation and Security Relearn Notice
Installing this module is a straightforward mechanical process. However, because the ECM is tied into your truck’s anti-theft system, a Vehicle Theft Deterrent (VTD) Relearn is often required after installation. This is a standard security procedure for modern GM vehicles.
IMPORTANT: If the truck does not start after installation, this VTD relearn procedure MUST be performed using a professional GM diagnostic tool (such as Tis2web or Techline Connect). This is the responsibility of the installer. Other vehicle-specific procedures, like a crankshaft position variation relearn or fuel injector flow rate programming, may also be necessary to ensure peak performance. We provide the correctly programmed module; the final on-vehicle setups are the buyer’s responsibility.
Simple Ordering Process:
- Purchase: Complete your order for this ECM.
- Provide VIN: Reply to our confirmation email or message us with your 17-digit VIN.
- We Program & Ship: We will program the module with the latest GM software matched to your VIN and ship it to you, ready for installation.
Guaranteed Fitment & Part Number Compatibility
This module, service number 12678815, is a direct replacement for several original part numbers. If your old module has any of the following numbers, this part is a 100% compatible replacement:
Replaces Part Numbers: 12692068, 12704476, 12686382, 12674052, 12674472, 12678815
This ECM fits the following vehicles:
- 2016-2018 GMC Sierra 1500 / Sierra Denali 1500
- 2016-2018 Chevrolet Silverado 1500
- 2017 Cadillac Escalade / Escalade ESV
- 2017 Chevrolet Tahoe / Suburban 1500
- 2017 GMC Yukon / Yukon XL 1500
- 2017 Cadillac ATS (3.6L LF4)
- 2017 Cadillac CTS (6.2L Supercharged or 3.6L LF3 Twin Turbo)
- 2017 Cadillac XTS (3.6L LF3)
- 2017 Chevrolet Corvette