Restore Peak Performance to Your General Motors Vehicle
Is your Cadillac, Chevrolet, or Buick suffering from puzzling issues like a persistent check engine light, rough idling, stalling, or a complete failure to start? These are classic signs of a failing Engine Control Module (ECM), the central computer that manages your engine’s performance, fuel efficiency, and emissions. A faulty ECM can create a cascade of problems that are often difficult and expensive to diagnose. This programmed ECM, part number 12653998, is the reliable and cost-effective solution to get your vehicle back on the road and running like new.
From the Diagnostic Bay
We had a 2014 Cadillac XTS in the shop that was driving its owner crazy. It would randomly stall at stoplights, the transmission would shift erratically, and the dash was lit up with a mix of engine and communication codes. The owner had already replaced a few sensors with no luck. After running a full diagnostic, we traced the communication errors back to the main hub: the ECM. It was failing intermittently, sending corrupt data across the vehicle’s network. We installed one of these VIN-programmed ECMs, performed the security relearn, and the car immediately ran perfectly. All the ghost codes vanished, and the stalling issue was completely resolved. It’s a reminder that sometimes, the ‘brain’ is the source of the problem.
Common Symptoms of a Failing Cadillac XTS ECM
- ✔ Persistent Check Engine Light (CEL) that won’t clear or returns immediately.
- ✔ Engine misfires, stumbles, or runs rough, especially under load.
- ✔ Unexplained drop in fuel economy.
- ✔ Vehicle stalls unexpectedly or has difficulty starting.
- ✔ Automatic transmission shifts harshly or at the wrong times.
- ✔ Complete no-start condition where the engine cranks but will not fire.
- ✔ Communication errors with diagnostic scan tools.
A Simple, Programmed Solution
Don’t waste time and money at the dealership with expensive new parts and programming fees. We’ve simplified the process. This is a thoroughly tested, used OEM ECM sourced from a salvaged vehicle. The key benefit is our in-house programming service. When you purchase, simply provide us with your vehicle’s 17-digit Vehicle Identification Number (VIN). Our technicians will then flash the module with the latest, most stable software updates directly from GM, ensuring it is perfectly matched to your vehicle’s specific configuration. This makes installation straightforward, getting you back on the road faster.
Broad Compatibility Across the GM Lineup
While this is a perfect solution for the Cadillac XTS ECM, part number 12653998 and its alternates (12633555, 12655007, 12644446) were used in a vast number of popular GM vehicles. This includes models like the Chevrolet Impala, Malibu, Equinox, Traverse, and Camaro, as well as the Buick LaCrosse, Regal, Enclave, and GMC Acadia and Terrain. Please review the detailed fitment list on this page to confirm this part is the correct one for your specific year, make, and model.
Frequently Asked Questions
Why do I need to provide my VIN?
Your VIN is essential for us to program the ECM correctly. It allows us to load the specific software, engine parameters, and security information for your exact vehicle. Without the correct VIN programming, the module will not function properly and may prevent your car from starting.
Is this part ready to install out of the box?
Yes, once we program the ECM with your VIN, it is ready for physical installation. However, most GM vehicles will require a simple security relearn procedure after installation to sync the new ECM with your vehicle’s anti-theft system. This can often be done without special tools and instructions can be readily found online for your model.
What does ‘used’ or ‘from a salvaged vehicle’ mean?
This means the part is a genuine OEM component that has been carefully removed from a vehicle that was taken out of service. Each unit is inspected and tested to ensure it is fully functional before being programmed and shipped. This is a sustainable and affordable way to get a high-quality, original part.
What if my original part number is one of the alternates listed?
The part numbers 12653998, 12633555, 12655007, and 12644446 are often interchangeable hardware versions. As long as your original part number is on our list, this ECM will function as a direct replacement once programmed to your VIN.
Do I need a professional mechanic to install this?
While the physical replacement of the ECM is straightforward for many DIY-ers (often just a few bolts and electrical connectors), we always recommend installation by a qualified automotive technician. They can ensure the installation and any necessary relearn procedures are performed correctly.