Restore Peak Performance to Your GM Truck or SUV
Is your 2017 GMC Yukon or other compatible GM vehicle suddenly running rough, refusing to start, or displaying a persistent Check Engine Light? You’re likely dealing with a frustrating and complex issue, but the solution is straightforward. As a technician with over two decades of experience under the hood, I’ve seen countless vehicles sidelined by a failing Engine Control Module (ECM). This isn’t just a part; it’s the brain of your engine’s operation, and when it falters, everything from fuel economy to shifting and ignition timing is compromised. This replacement ECM, part number 12678815, is the reliable, professional-grade solution to get you back on the road with confidence.
We take the biggest headache out of the replacement process. Before this module ever leaves our facility, it is professionally programmed with the latest GM-certified software calibrations, tailored specifically to your vehicle’s VIN. This eliminates the need for an expensive trip to the dealership for programming. You get a component that is ready for installation right out of the box, saving you significant time and money.
Case Study: A Tricky Diagnosis
I once had a 2017 Sierra 1500 in my bay with a phantom no-start condition. It would run perfectly for weeks, then suddenly refuse to crank. All the basic checks (battery, starter, fuses) were fine. The owner had already replaced the battery twice. The scan tool showed intermittent U0100 (Lost Communication with ECM) codes, which can often point to a wiring issue. After hours tracing harnesses, I noticed the ECM was getting extremely hot to the touch. On a hunch, I used a heat gun to carefully warm the module, and the no-start condition returned every time. The internal processors were failing under thermal stress—a classic sign of a dying ECM. Replacing it with a pre-programmed unit like this one solved the problem permanently. It’s not always the most obvious part, but a failing ECM can cause some of the most confusing symptoms.
Is Your GM Vehicle Showing These Signs?
A faulty ECM can manifest in numerous ways. If you’re experiencing any of the following, a failing engine computer is a likely culprit:
- ✔ Check Engine Light is on with codes like P0601, P0606, or U0100.
- ✔ The vehicle cranks but refuses to start.
- ✔ Intermittent stalling or engine hesitation, especially when warm.
- ✔ A noticeable drop in fuel efficiency.
- ✔ Poor or erratic automatic transmission shifting.
- ✔ Communication issues with your diagnostic scan tool.
Your Straightforward Installation Guide
Replacing your 2017 Yukon Engine Control Module is a manageable job for a DIY enthusiast or a quick task for a professional. Follow these steps for a successful installation. Please note: Access to a GM diagnostic tool (like TIS2WEB/Techline Connect) may be required for post-installation procedures.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before beginning any electrical work.
- Locate the ECM: On most compatible trucks and SUVs (like the Yukon, Tahoe, Sierra, Silverado), the ECM is located in the engine compartment on the driver’s side, near the firewall or inner fender.
- Disconnect Connectors: Carefully release the locking tabs and unplug the wiring harnesses from the old ECM. Inspect the connectors for any corrosion or damage.
- Remove the Old Module: Unbolt the old ECM from its mounting bracket. Keep the hardware as you will need it for the new module.
- Install the New ECM: Mount your new, pre-programmed ECM onto the bracket and securely fasten it. Reconnect the wiring harnesses, ensuring they click firmly into place.
- Reconnect Battery: Reattach the negative battery terminal.
- Theft Deterrent Relearn: Attempt to start the vehicle. If it does not start, a Vehicle Theft Deterrent System (VTDS) relearn is required. This procedure pairs the new ECM to your vehicle’s security system and must be performed using a compatible GM diagnostic interface. This is a mandatory step for vehicle security and is the responsibility of the installer.
- Additional Relearns: Depending on your vehicle, other procedures like a Crankshaft Variation Relearn or injector flow rate programming may be necessary to ensure optimal performance.
Verified Fitment For These GM Models
This engine control module is a direct replacement for part number 12678815 and is also compatible with part numbers 12692068, 12704476, 12686382, 12674052, and 12674472. It fits a wide range of popular GM vehicles. Please verify your model and options below:
ESCALADE & ESCALADE ESV 2017 (Engine Compartment)
XTS 2017 (3.6L Twin Turbo, VIN 8, opt LF3)
CTS 2017 (6.2L Supercharged) & (3.6L Twin Turbo, VIN 8, opt LF3)
ATS 2017 (3.6L, VIN Y, opt LF4)
Chevrolet:
TAHOE 2017 (LH Front Engine Compartment)
SUBURBAN 1500 2017 (LH Front Engine Compartment)
CORVETTE 2017 (RH Cowl Under Dash)
SILVERADO 1500 PICKUP 2016 (ID 12674472)
SILVERADO 1500 PICKUP 2017 (LH Front Engine Compartment)
SILVERADO 1500 PICKUP 2018 (ID 12686382)
GMC:
YUKON & YUKON XL 1500 2017 (LH Front Engine Compartment)
SIERRA 1500 PICKUP 2016 (ID 12674472)
SIERRA 1500 & SIERRA DENALI 1500 2017 (LH Front Engine Compartment)
SIERRA 1500 & SIERRA DENALI 1500 2018 (ID 12686382)
Frequently Asked Questions
Why do you need my VIN?
Why do you need my VIN?
Your Vehicle Identification Number (VIN) is essential. We use it to load the exact, correct GM software and calibrations for your specific vehicle’s engine, transmission, and options. This ensures your new 2017 Yukon Engine Control Module works perfectly right out of the box.
What is a ‘theft relearn’ and do I have to do it?
The theft deterrent relearn is a security procedure that syncs the new ECM to your vehicle’s ignition keys and anti-theft system. If the vehicle doesn’t start after installation, this procedure is required. It must be done with a professional GM diagnostic tool. It is a necessary step and the responsibility of the installer.
Is this a used part from a junkyard?
No. This is a high-quality, inspected, and tested replacement module. Unlike a junkyard part with an unknown history, this unit is verified to be fully functional and is then programmed with fresh, updated software for your vehicle, providing a reliable and lasting repair.
Will this fix my check engine light?
If the check engine light is caused by an internal failure of the ECM (common codes P0601-P0606), then yes, this part will resolve the issue. However, you should always perform a complete diagnosis to ensure the codes are not being caused by other failing sensors or wiring problems.
Do I need to program this module?
No, the main engine programming is done by us before shipping! You just need to provide your VIN at checkout. The only additional steps you or your mechanic might need to perform after installation are the security relearn and potentially other minor setup procedures like the crankshaft position sensor relearn.