Get Your Truck Back on the Road, Fast.
There’s nothing more frustrating than a truck that won’t start, runs poorly, or throws a cascade of confusing check engine lights. As a technician with over 20 years in the bay, I’ve seen it countless times. The Engine Control Module (ECM) is the brain of your vehicle’s operation, and when it fails, it can cause chaos. This isn’t just a part; it’s the solution to getting your reliable workhorse back in action. This module, part number 12704476, is a direct-fit replacement for your 2016-2018 GM truck, and it arrives at your door pre-programmed with the latest GM software updates specifically for your vehicle’s VIN.
We take the biggest headache out of the equation: programming. Forget towing your truck to the dealership and paying high labor rates for flashing. Simply provide us with your VIN during checkout, and our experts will handle the calibration. This ensures that when you install the 2016-2018 Sierra 1500 ECM, it’s already configured to communicate perfectly with your truck’s engine, transmission, and other systems.
A Technician’s Notebook: The Intermittent Stall
I once had a 2017 Silverado in my shop that was a real head-scratcher. The owner reported random stalling at stoplights, but it never threw a consistent code. We checked fuel pressure, sensors, and wiring harnesses for days. Finally, on a hunch, we monitored the live data stream from the ECM and noticed the processor would momentarily drop offline right before a stall. A new, properly programmed ECM fixed it instantly. A failing module doesn’t always die completely; sometimes it just becomes unreliable, causing problems that seem impossible to trace. This is why a quality replacement is non-negotiable.
Is Your Truck Showing These Symptoms?
A failing ECM can manifest in various ways. If you’re experiencing any of the following, a faulty engine computer is a likely culprit:
- ✔ Vehicle will not start or has a hard starting condition.
- ✔ Check Engine Light is on with communication-related Diagnostic Trouble Codes (DTCs) like U0100 (Lost Communication with ECM/PCM).
- ✔ Internal module failure codes are present, such as P0601, P0606, or P062F.
- ✔ Erratic engine performance, such as misfiring, poor fuel economy, or hesitation.
- ✔ Seemingly unrelated warning lights on the dash.
- ✔ Transmission shifting issues or failure to go into gear.
A Straightforward Guide to Installation
Replacing your 2016-2018 Sierra 1500 ECM is a manageable job for a confident DIYer or any professional technician. Follow these general steps to ensure a smooth process.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before beginning any electrical work.
- Locate the ECM: On most 2016-2018 GM trucks, the ECM is located in the engine compartment on the driver’s side, near the firewall or inner fender.
- Disconnect and Remove: Carefully unplug the electrical connectors. They have locking tabs that need to be released. Once disconnected, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new ECM into place and securely reconnect all electrical connectors. Ensure they click into place.
- Reconnect the Battery: Re-attach the negative battery terminal.
- Perform Relearn Procedures: This is a critical final step. Your vehicle will not start until a Vehicle Theft Deterrent (VTD) relearn is completed using a compatible GM diagnostic tool (like Tis2web/Techline Connect). Other procedures like a Crankshaft Variation Relearn may also be necessary.
IMPORTANT NOTICE: We supply this 2016-2018 Sierra 1500 ECM programmed to your VIN. However, the final security handshake—the VTD relearn—and any other necessary setup procedures must be performed by the end-user or their technician. This is a standard security feature on all modern GM vehicles.
Verified Vehicle Compatibility
This module is a direct replacement for part numbers 12692068, 12704476, 12686382, 12674052, 12674472, and 12678815. It is confirmed to fit the following vehicles:
- ✔ 2017 Cadillac Escalade & Escalade ESV
- ✔ 2017 Cadillac XTS (3.6L Twin Turbo, VIN 8)
- ✔ 2017 Chevrolet Tahoe & Suburban 1500
- ✔ 2017 GMC Yukon & Yukon XL 1500
- ✔ 2017 Cadillac CTS (6.2L Supercharged or 3.6L Twin Turbo)
- ✔ 2017 Chevrolet Corvette
- ✔ 2017 Cadillac ATS (3.6L, VIN Y)
- ✔ 2016-2018 GMC Sierra 1500 / Sierra Denali 1500
- ✔ 2016-2018 Chevrolet Silverado 1500
Do I need to send my old ECM to you?
Do I need to send my old ECM to you?
No, a core return is not required. This is a direct purchase. We program and ship the replacement module to you after you provide your vehicle’s VIN.
What is a Vehicle Theft Deterrent (VTD) relearn?
The VTD relearn is a security procedure that syncs your new ECM to your vehicle’s ignition key and body control module. Without this step, the vehicle’s anti-theft system will prevent it from starting. It requires a professional scan tool with GM software capabilities, such as Techline Connect.
Can I perform the relearn procedures myself?
Unless you have access to and are proficient with GM’s professional diagnostic and programming software (Tis2web/Techline Connect), you will need to have a qualified automotive shop or mobile technician perform the final relearn procedures after you install the part.
Is this part new or used?
This is a high-quality, tested, and verified used component that has been expertly programmed with the latest factory software for your specific VIN, ensuring reliable performance and compatibility.
What happens if I provide the wrong VIN?
The programming is specific to the VIN you provide. An incorrect VIN will result in the wrong calibrations being loaded, and the module will not function correctly in your vehicle. Please double-check your VIN from your driver’s side door jamb sticker or registration before sending it to us.