Restore Your Vehicle’s Core Performance and Reliability
If you’re dealing with frustrating issues like a persistent check engine light, erratic engine behavior, stalling, or a no-start condition in your GM vehicle, a failing Engine Control Module (ECM) is often the culprit. As the central computer of your vehicle, the ECM manages everything from fuel mixture and ignition timing to transmission shifting. When it falters, the entire system suffers. This isn’t just an inconvenience; it’s a critical failure that compromises performance and safety. This module, part number 12704476, is the definitive solution, arriving pre-programmed with the latest GM software specifically for your vehicle’s VIN.
Case Study: A Tricky Diagnosis
I recently had a 2017 Cadillac CTS-V in my bay with a maddeningly intermittent problem. The owner reported random stalling at low speeds and occasional no-start conditions, but with no consistent trouble codes. We checked the fuel pump, ignition system, and wiring harnesses—all tested fine. After hours of diagnostics, we monitored live data during a test drive and saw the ECM’s voltage reference momentarily drop out, causing the system to reset. It was a classic sign of internal ECM failure that a simple code scan would miss. We replaced the module with a VIN-programmed unit like this one, performed the security relearn, and the car has run flawlessly ever since. It’s a reminder that the right part, correctly programmed, is the only way to solve these complex electronic issues for good.
Is Your GM Vehicle Showing These Signs of ECM Failure?
- âś” Unexplained check engine light with codes like P0601, P0606, or U0100.
- âś” The engine cranks but refuses to start.
- âś” Noticeable decrease in fuel economy.
- âś” Rough idling, stalling, or hesitation during acceleration.
- âś” Harsh or erratic automatic transmission shifting.
- âś” Communication errors with other vehicle modules.
- âś” Apparent loss of spark or fuel injector pulse.
Your Straightforward Installation Path
Installing your new 2017 ATS Engine Control Module is a manageable job for a seasoned DIYer or any professional technician. Follow these general steps to get your vehicle back in top shape.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before beginning any electronic work.
- Locate the ECM: On most compatible models (like the Silverado, Tahoe, or ATS), the ECM is found in the engine compartment, typically on the driver’s side. Refer to your vehicle’s service manual for the exact location.
- Disconnect and Remove: Carefully unplug the electrical connectors. They have locking tabs that must be released. Once disconnected, unbolt the old module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed ECM into place. Securely reconnect the electrical connectors, ensuring they click and lock into position.
- Reconnect Power: Re-attach the negative battery terminal.
- CRITICAL FINAL STEP – Security Relearn: The vehicle will NOT start until a Vehicle Theft Deterrent (VTD) relearn is performed. This procedure syncs the new ECM with your vehicle’s security system. This requires a compatible scan tool or access to GM’s TIS2Web/Techline Connect service. Additional procedures like a crankshaft variation relearn may also be necessary.
Verified Compatibility for Your Vehicle
This module is a direct-fit replacement for a wide range of GM cars, trucks, and SUVs. Please verify your vehicle and options below. This part is interchangeable with part numbers: 12692068, 12704476, 12686382, 12674052, 12674472, and 12678815.
- Cadillac ATS: 2017 (3.6L, VIN Y, LF4)
- Cadillac CTS: 2017 (6.2L Supercharged or 3.6L Twin Turbo VIN 8, LF3)
- Cadillac Escalade / ESV: 2017
- Cadillac XTS: 2017 (3.6L, VIN 8, LF3)
- Chevrolet Corvette: 2017
- Chevrolet Silverado 1500: 2016 (ID 12674472), 2017, 2018 (ID 12686382)
- Chevrolet Suburban 1500: 2017
- Chevrolet Tahoe: 2017
- GMC Sierra 1500 / Denali 1500: 2016 (ID 12674472), 2017, 2018 (ID 12686382)
- GMC Yukon / Yukon XL 1500: 2017
Frequently Asked Questions
Why do you need my VIN to sell me this part?
Your Vehicle Identification Number (VIN) is essential because it allows us to program the Engine Control Module with the exact software and calibrations specified by GM for your vehicle’s unique configuration, including engine, transmission, and emissions equipment. This ensures proper function and compatibility right out of the box.
What is a ‘theft relearn’ and can I skip it?
A theft relearn (or VTD relearn) is a mandatory security procedure that synchronizes the new ECM with your vehicle’s immobilizer system. You cannot skip this step. Without it, the security system will assume the vehicle is being stolen and will prevent the engine from starting.
Can I install this 2017 ATS Engine Control Module myself?
The physical installation is straightforward for those with mechanical experience. However, the final, mandatory security relearn and any other required setup procedures (like crankshaft variation) require professional-grade scan tools or access to GM’s software (TIS2Web/Techline Connect). We recommend installation by a qualified technician.
Will this fix my check engine light?
If the check engine light and other symptoms are caused by a faulty ECM, this part will resolve the issue once installed and programmed correctly. However, if the light is on due to another failing component (like an oxygen sensor or catalytic converter), this part will not fix that underlying problem.
Does this part replace other part numbers?
Yes, this ECM is a direct, compatible replacement for several GM part numbers, including 12692068, 12686382, 12674052, 12674472, and 12678815. Ordering this part ensures you receive a correct and updated component.