Restore Your Cadillac’s Core Performance and Reliability
Is your 2014-2016 Cadillac XTS suffering from frustrating and unpredictable issues? A nagging check engine light, sudden stalling, poor fuel mileage, or a complete no-start condition can often be traced back to a single component: the Engine Control Module (ECM). As the central computer of your vehicle, a failing ECM can cause a cascade of problems that are difficult to diagnose. This isn’t just an inconvenience; it’s a matter of reliability and safety. Stop throwing parts at the problem and get to the root of the issue with a dependable, correctly programmed replacement.
This isn’t just a part in a box. This is a complete solution. We are providing a genuine GM Engine Control Module, part number 12662034, that will be professionally programmed with the latest software updates from General Motors specifically for your vehicle. All we need is your vehicle’s 17-digit VIN during checkout. This critical step ensures that when the module arrives, it’s ready to be installed, saving you from expensive dealership programming fees and the hassle of towing your vehicle. This is the most efficient way to get your luxury sedan back on the road, running as it should.
A Technician’s Notebook: The Intermittent Gremlin
I had a 2015 Cadillac XTS in my bay that was a real head-scratcher. The owner complained of random no-start conditions—it would be fine for weeks, then leave him stranded without warning. There were no consistent trouble codes, just a few sporadic communication errors (U-codes) that would clear. We checked the battery, alternator, and starter, all tested fine. After hours of tracing wires, I suspected the ECM. On these models, internal solder joints can develop micro-fractures from heat cycles, causing intermittent connection loss. We swapped in a pre-programmed ECM, and the problem vanished instantly. It’s a classic case where the “brain” itself is the culprit, and a direct, programmed replacement is the only surefire fix.
Is Your Vehicle Exhibiting These Symptoms?
A faulty ECM can manifest in numerous ways. If you’re experiencing any of the following, it’s a strong indicator that your engine’s computer may need replacement. In my 20+ years of experience, these are the most common signs:
- ✔ Check Engine Light is illuminated with no obvious cause.
- ✔ Stored Diagnostic Trouble Codes (DTCs) related to internal module failure, such as P0601, P0606, or P062F.
- ✔ Communication errors with other modules, often showing as U-codes (e.g., U0100 – Lost Communication with ECM).
- ✔ Engine stalls unexpectedly or refuses to start at all.
- ✔ Noticeable decrease in fuel economy.
- ✔ Rough idling, misfires, or hesitation during acceleration.
- ✔ Problems with the automatic transmission shifting erratically.
A Straightforward Guide to Installation
For the confident DIYer or professional mechanic, installing this 2014-2016 XTS ECM is a manageable job that requires no special programming tools on your end. The key is our pre-programming service.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent accidental reconnection.
- Locate the ECM: On the Cadillac XTS, the Engine Control Module is typically found in the engine bay, mounted to the driver’s side strut tower or firewall. It’s a silver box with multiple large electrical connectors.
- Disconnect and Remove: Carefully unplug the electrical connectors. There are usually locking tabs that need to be released. Once disconnected, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed ECM into place. Reconnect the electrical connectors, ensuring they click securely into position.
- Reconnect Power: Reattach the negative battery terminal.
- Perform Relearn Procedure (If Necessary): In some cases, a simple security or idle relearn procedure may be required. This can often be done by cycling the key or letting the vehicle idle for a few minutes. Consult your vehicle’s service information for specific steps if needed.
Verified Vehicle Compatibility
This module is a direct replacement for part number 12662034 and several other interchangeable numbers. It is guaranteed to fit a wide range of GM cars, trucks, and SUVs. Please verify your vehicle is on this list before ordering:
Cadillac: XTS (2014-16, 3.6L LF3), ATS (2014-16, 3.6L), CTS (2014-16, 3.6L/6.2L), Escalade/ESV (2015-16)
Chevrolet: Silverado 1500 (2014-16), Corvette (2014-16), Camaro (2016, 6.2L), Colorado (2015-16, 3.6L), Suburban 1500 (2015-16), Tahoe (2015-16)
GMC: Sierra 1500 / Denali 1500 (2014-16), Canyon (2015-16, 3.6L), Yukon / Yukon XL 1500 (2015-16)
Note: This module is compatible with multiple part numbers, including 12692067, 12676230, 12656993, 12672537, and more. If your old module has one of these numbers, this part will work for you.
Frequently Asked Questions
Frequently Asked Questions
Do I need to do any programming or flashing myself?
No. We handle all the programming before shipment. Using the VIN you provide, we load the latest GM-certified calibration file onto the module. It arrives ready for installation.
Is this a new or used part?
This is a high-quality, inspected, and tested used OEM part that has been verified to be in excellent working condition before being programmed for your specific vehicle.
Where do I provide my VIN?
Please enter your 17-digit Vehicle Identification Number (VIN) in the notes section during checkout or send it to us in a message immediately after your purchase. We cannot ship your order without it.
What is the warranty on this 2014-2016 XTS ECM?
This part comes with our standard warranty, ensuring it is free from defects upon arrival and functions correctly once installed. Please see our warranty page for full details.
Will this fix my check engine light?
If the check engine light is caused by an internal failure of the ECM (like codes P0601-P0606), then yes, this part is the correct fix. However, it’s crucial to properly diagnose your vehicle, as other faulty sensors or components can also trigger the light.