Restore Your GM Truck’s Brainpower and Performance
Is your 2017 GMC Yukon XL 1500 acting up? Experiencing frustrating issues like a no-start condition, erratic idling, poor fuel mileage, or a persistent Check Engine Light that just won’t go away? The problem often lies with the Engine Control Module (ECM), the central computer that manages everything from fuel injection and ignition timing to transmission shifts. When it fails, your vehicle’s performance and reliability suffer dramatically.
As a technician with over two decades of experience, I’ve seen firsthand how a faulty ECM can cause a cascade of confusing symptoms. This isn’t just a part; it’s the command center for your engine. That’s why we offer a straightforward, reliable solution. This genuine GM Engine Control Module, part number 12678815, is the correct fix for a wide range of GM trucks and SUVs. The best part? We take the biggest headache out of the equation. Simply provide your vehicle’s VIN during checkout, and we will program the module with the latest, most stable GM factory software specifically for your vehicle before it even leaves our facility. This ensures it communicates perfectly with the other modules in your truck, restoring the performance and efficiency you expect.
From the Diagnostic Bay: The Intermittent Gremlin
I remember a 2017 Sierra 1500 that came into the shop with a list of bizarre, intermittent complaints. The owner reported random stalling at stoplights, occasional hard shifts, and a flickering Check Engine Light. We couldn’t replicate the issue consistently. After checking all the usual suspects—sensors, wiring, fuel pressure—we focused on the ECM. On a hunch, we monitored the live data stream and finally caught it: the ECM was momentarily losing communication, causing the random faults. We installed a VIN-programmed module just like this one. The owner called a week later, thrilled that his ‘haunted’ truck was finally fixed. This simple swap saved hours of further diagnostic time and gave him a permanent solution.
Is Your GM Truck Showing These Telltale Signs?
A failing ECM can manifest in many ways. If you’re experiencing any of the following, this module is likely the solution you need. Look out for these common symptoms and associated Diagnostic Trouble Codes (DTCs):
- ✔ Check Engine Light is illuminated with codes such as P0601 (Internal Control Module Memory Check Sum Error) or P0606 (ECM/PCM Processor Fault).
- ✔ The engine cranks but refuses to start.
- ✔ Unexpected stalling or rough, inconsistent idling.
- ✔ Noticeable decrease in fuel economy.
- ✔ Poor engine performance, hesitation, or misfires.
- ✔ Communication errors with other modules, sometimes triggering a U0100 (Lost Communication With ECM/PCM) code.
- ✔ Problems with the automatic transmission shifting properly.
Your Straightforward ECM Installation Guide
Replacing the ECM is a manageable job for a confident DIYer or any professional mechanic. With the programming already handled by us, you’re several steps ahead. Follow this general guide for a successful installation:
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 15 minutes to allow capacitors to discharge.
- Locate the ECM: On most compatible trucks and SUVs like the Yukon XL, Tahoe, and Silverado, the ECM is located in the engine compartment on the driver’s side, often near the air filter box. On other models like the Corvette, it may be in the cowl area.
- Disconnect Connectors: Carefully release the locking tabs on the electrical connectors and pull them straight out from the module. Never force them. Inspect the pins 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 unit.
- Install the New ECM: Mount your new, pre-programmed module in place and secure it with the original hardware. Reconnect the electrical connectors, ensuring they click securely into place.
- Reconnect Battery: Reattach the negative battery terminal.
- Perform Relearn Procedures: This is a critical final step. If the vehicle does not start, you must perform the Vehicle Theft Deterrent (VTD) relearn using a compatible scan tool or GM’s TIS2Web/Techline Connect system. Other procedures, like a crankshaft position variation relearn, may also be necessary to ensure optimal performance. This is the responsibility of the installer.
Verified Vehicle Compatibility List
This module is a direct-fit replacement for several GM vehicles and part numbers. Please verify your vehicle and original part number below. This unit is a confirmed replacement for part numbers: 12692068, 12704476, 12686382, 12674052, 12674472, and 12678815.
Fits these makes and models with specified options:
- 2017 Cadillac Escalade & Escalade ESV
- 2017 Cadillac XTS (3.6L, VIN 8, opt LF3)
- 2017 Chevrolet Tahoe
- 2017 GMC Yukon & Yukon XL 1500
- 2017 Cadillac CTS (6.2L Supercharged or 3.6L Twin Turbo)
- 2017 Chevrolet Corvette
- 2016-2018 Chevrolet Silverado 1500 (check IDs for 16/18)
- 2017 Chevrolet Suburban 1500
- 2016-2018 GMC Sierra 1500 & Sierra Denali 1500 (check IDs for 16/18)
- 2017 Cadillac ATS (3.6L, VIN Y, opt LF4)
Frequently Asked Questions
Do I need to do any programming myself?
No. We handle the main programming for you. We flash the module with the latest GM software matched to your vehicle’s VIN before we ship it. You will, however, need to perform the final vehicle-side relearn procedures after installation, such as the VTD relearn.
What is a VTD or theft relearn?
The Vehicle Theft Deterrent (VTD) relearn is a security procedure that syncs the new ECM to your vehicle’s ignition key and security system. If this isn’t done, the system will assume a theft is in progress and prevent the engine from starting. This requires a professional scan tool with GM software capabilities.
How do I provide my VIN?
After you complete your purchase, you will need to send us your 17-digit Vehicle Identification Number (VIN). We cannot program and ship the module without it. Please double-check it for accuracy to avoid delays.
Will this fix my specific problem?
This module corrects issues directly caused by a faulty ECM, such as internal processor faults (P0606) or memory errors (P0601). While it resolves the most common symptoms, it’s crucial to ensure your vehicle has been properly diagnosed by a qualified technician, as other issues (like bad wiring or failed sensors) can sometimes mimic ECM failure.
Is this a brand new part?
This is a high-quality, tested, and verified genuine GM part, guaranteed to function correctly once programmed and installed. We ensure every module meets strict performance standards before it is sent to you.