Is Your Cadillac XTS Running Rough, Stalling, or Refusing to Start?
As a technician with over two decades of experience under the hood, I know the frustration of a vehicle that’s lost its reliability. When a sophisticated car like a 2017-2019 Cadillac XTS starts acting up—with a persistent Check Engine Light, sudden stalling, poor acceleration, or a complete no-start condition—the Engine Control Module (ECM) is often the culprit. The ECM is the brain of your engine, and when it fails, it can cause a cascade of confusing and costly problems.
From the Shop Floor: A Real-World Diagnosis
Just last month, a 2018 XTS with the 3.6L LFX engine was towed into my bay. The owner was at his wit’s end; the car would crank but never fire up. He’d already replaced the battery and checked fuses. My diagnostic scanner couldn’t communicate with the engine computer, throwing a U0100 code (Lost Communication With ECM/PCM). After confirming the module had proper power and ground at the main connector—a critical first step—it was clear the ECM itself had failed internally. This is a scenario I’ve diagnosed hundreds of times on modern GM vehicles.
The Simple, Reliable Solution: A Pre-Programmed 2017-2019 XTS Engine Module
Forget the hassle and high cost of a dealership visit. This Engine Control Module is the direct, effective solution to get your Cadillac running smoothly again. We take the guesswork out of the repair by programming the module specifically for your vehicle before it ever leaves our facility. All we need is your Vehicle Identification Number (VIN) at checkout. This ensures all the factory settings and performance parameters for your exact car are loaded and ready to go.
- ✔ VIN-Programmed for Your XTS: Arrives with the latest GM software updates, matched precisely to your vehicle.
- ✔ No Dealer Visit Needed: This is a true plug-and-play solution, saving you hundreds in programming fees and towing costs.
- ✔ Restores Original Performance: Cures common symptoms like stalling, rough idle, no-start conditions, and false sensor codes.
- ✔ Direct-Fit Replacement: Guaranteed to fit and function just like the original, replacing part numbers 12666070, 12667002, and 12667189.
Easy Installation Guide: Get Back on the Road Fast
Installing your new ECM is a straightforward process you can do with basic hand tools. Follow these steps carefully for a successful repair.
- Safety First: Disconnect the negative terminal from your vehicle’s battery and secure it away from the post.
- Locate the ECM: On the 2017-2019 XTS, the ECM is typically found in the engine compartment, often on the driver’s side near the firewall or air filter housing.
- Disconnect Connectors: Carefully release the locking tabs on the electrical harness connectors and pull them straight out from the old module. Never force them.
- Remove Old Module: Unbolt the old ECM from its mounting bracket and remove it from the vehicle.
- Install New Module: Mount your new, pre-programmed ECM onto the bracket and securely tighten the bolts.
- Reconnect & Secure: Plug the harness connectors firmly into the new module until they click into place. Reconnect the negative battery terminal.
- Perform Relearn (If Needed): In some cases, a simple Security Relearn Procedure may be required. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then off, and repeating two more times before starting the engine.
Expert Pro Tip: Connector Inspection is Non-Negotiable
Before you plug in your new ECM, take 60 seconds to thoroughly inspect the vehicle’s harness connectors. Look for any green or white powdery residue (corrosion), moisture, or bent/damaged pins. A compromised connection is the leading cause of repeat module failure. If you see any contamination, use a dedicated electronics cleaner and a small, soft brush to gently clean the terminals. A clean connection ensures a long service life for your new part.
Guaranteed Fitment for Your Vehicle
This module is a confirmed fit for the following vehicles and options. Please verify your vehicle is on this list before ordering.
- Cadillac XTS: 2017-2019 (3.6L, VIN 3 – 8th digit, opt LFX)
- Cadillac SRX: 2016 (3.6L)
- Chevrolet Caprice: 2017 (3.6L)
- Chevrolet Traverse: 2017 (Behind fan shroud)
- Chevrolet Impala: 2017-2019
- Chevrolet Equinox: 2017 (LH engine compartment)
- GMC Acadia: 2017 (VIN J – 11th digit, Limited)
- GMC Terrain: 2017 (LH engine compartment)
- Buick Enclave: 2017 (Behind fan shroud)
- Buick Regal: 2017 (LH engine compartment)
- Buick Verano: 2017
Don’t let a faulty computer keep your Cadillac parked. Order your pre-programmed ECM today and restore the performance and peace of mind you expect from your vehicle.