Restore Peak Performance to Your GM Vehicle
Is your Cadillac, Chevrolet, or GMC acting up? Stalling, poor fuel economy, a persistent Check Engine Light, or a frustrating no-start condition can often point directly to a failing Engine Control Module (ECM). As the central computer for your engine, when the ECM falters, the entire vehicle suffers. This isn’t just an inconvenience; it’s a critical failure that compromises reliability and safety. In my 20+ years of experience, I’ve seen countless drivers spend a fortune chasing down phantom sensor issues when the root cause was the ECM itself.
This replacement ECM is the definitive solution for a wide range of GM vehicles, including the 2017 XTS Engine Control Module. We take the guesswork and hassle out of the repair by pre-programming the module to your vehicle’s specific Vehicle Identification Number (VIN). Simply provide us with your VIN at checkout, and we’ll load the latest, most stable GM factory software onto the unit before it even leaves our facility. This means no expensive trip to the dealership for programming—a savings of both time and money.
A Technician’s Notebook
I remember a 2017 Cadillac CTS with the 3.6L twin-turbo that came into the shop on a tow truck. The owner had replaced the battery and alternator, but it would still crank but not start intermittently. We weren’t getting any spark or injector pulse, but the codes were all over the place—U0100 (Lost Communication with ECM), P0606 (ECM Processor Fault), and a few others that seemed unrelated. After verifying power and ground to the module, we knew the ECM was the culprit. Swapping in a VIN-programmed module like this one, followed by a quick 10-minute security relearn, had the car firing up perfectly. The customer was thrilled to avoid a massive dealership bill and get his car back the same day.
Is Your GM Vehicle Showing These Signs?
- ✔ Complete no-start or crank-no-start condition.
- ✔ Check Engine Light is on with internal processor codes (e.g., P0601, P0602, P0606).
- ✔ Communication errors with scan tools or other modules (U-codes).
- ✔ Erratic engine performance, such as stalling, misfiring, or hesitation.
- ✔ Noticeable decrease in fuel efficiency.
- ✔ Issues with automatic transmission shifting.
- ✔ Seemingly random electrical problems or warning lights.
Your Straightforward Installation Guide
Replacing your 2017 XTS Engine Control Module is a manageable job for a confident DIYer or any professional technician. Follow these steps for a successful installation.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 10 minutes to allow the system to fully discharge.
- Locate the ECM: The location varies by model. On many GM trucks and SUVs, it’s on the LH front of the engine compartment. On cars like the Corvette or XTS, it may be under the dash or in the cowl area. Refer to a service manual for your specific vehicle.
- Disconnect Connectors: Carefully release the locking tabs on the electrical connectors and pull them straight out. Do not force them. Inspect the pins for any corrosion or damage.
- Remove the Old Module: Unbolt the old ECM from its mounting bracket and remove it from the vehicle.
- Install the New Module: Mount your new, pre-programmed ECM and securely fasten the bolts. Reconnect the electrical connectors, ensuring they click into place.
- Reconnect the Battery: Reattach the negative battery terminal.
- Perform Security Relearn: This is the most critical step. If the vehicle does not start, you must perform a Vehicle Theft Deterrent (VTD) relearn. This procedure requires a GM-compatible scan tool with access to TIS2Web or Techline Connect. This synchronizes the new ECM with your vehicle’s anti-theft system. Other procedures like a Crankshaft Variation Relearn may also be required.
NOTICE: The buyer is responsible for performing the VTD relearn and any other necessary setup procedures. We provide the correctly programmed part; the final integration with the vehicle must be completed upon installation.
Verified Compatibility for Your GM Vehicle
This module is a direct replacement for part number 12678815 and is interchangeable with part numbers 12692068, 12704476, 12686382, 12674052, and 12674472. It fits the following models:
- 2017 Cadillac ATS: (3.6L, VIN Y, opt LF4)
- 2017 Cadillac CTS: (6.2L Supercharged)
- 2017 Cadillac CTS: (3.6L, VIN 8, opt LF3, twin turbo)
- 2017 Cadillac Escalade & ESV
- 2017 Cadillac XTS: (3.6L, VIN 8, opt LF3)
- 2017 Chevrolet Corvette: (RH cowl under dash)
- 2016-2018 Chevrolet Silverado 1500
- 2017 Chevrolet Suburban 1500
- 2017 Chevrolet Tahoe
- 2016-2018 GMC Sierra 1500 & Sierra Denali 1500
- 2017 GMC Yukon & Yukon XL 1500
Frequently Asked Questions
Why do you need my VIN?
Your VIN is essential for us to program the Engine Control Module with the exact software and calibrations specified by GM for your vehicle’s engine, transmission, and options. This ensures proper function and compatibility right out of the box.
What is a theft relearn and can I do it myself?
The Vehicle Theft Deterrent (VTD) relearn synchronizes the new ECM to your car’s security system. Without it, the vehicle will not start. This procedure typically requires a professional-grade scan tool with access to GM’s TIS2Web/Techline Connect software. Most DIYers will need assistance from a qualified mechanic or mobile technician to complete this step.
Will this fix my check engine light?
If your check engine light is caused by an internal ECM failure (like codes P0601-P0606), then yes, this part is the correct fix. However, if the light is on for other reasons (e.g., a bad oxygen sensor), you will still need to diagnose and repair that separate issue.
Do I need to match the part number exactly?
This module, 12678815, also replaces several other part numbers like 12692068, 12704476, and more. As long as your vehicle is on our compatibility list, this module will work, as the specific programming we perform makes it a correct fit.
What if my vehicle has other issues besides the ECM?
This module will solve problems directly related to a faulty ECM. It’s crucial to ensure your vehicle’s wiring, power, and grounds are in good condition. A proper diagnosis is key. This module will not fix issues caused by other faulty components.