Is Your Cadillac STS Running Rough? The Solution is Here.
If you’re experiencing frustrating issues like a persistent check engine light, poor fuel economy, engine stalling, or a no-start condition in your 2006 Cadillac STS, a failing Engine Control Module (ECM) is a very likely culprit. The ECM is the central computer of your vehicle’s powertrain, responsible for managing everything from fuel injection and ignition timing to transmission shifts and emissions control. When it fails, the symptoms can be widespread and difficult to diagnose, but replacing it doesn’t have to be a trip to the dealership.
This is a direct-fit replacement Engine Control Module for your vehicle, part number 12630457. To ensure a seamless and correct installation, we professionally program this module to your vehicle’s specific Vehicle Identification Number (VIN) before it ships. This crucial step loads the latest GM-certified software and calibrations, making the unit truly plug-and-play. You can restore your vehicle’s performance and reliability without the high cost and hassle of dealer programming.
From the Diagnostic Bay
We had a 2008 Chevy Impala come in with a bizarre issue: it would run perfectly for about 15 minutes, then suddenly start misfiring on multiple cylinders and lose power. The check engine light would flash, throwing random misfire codes. The owner had already replaced plugs, coils, and even the fuel pump with no success. After hooking up our diagnostic scanner and monitoring live data, we noticed the short-term fuel trim values going haywire right before the issue started. This pointed not to a mechanical part, but to the computer making bad decisions. We swapped in a VIN-programmed ECM, and the car ran perfectly. It was a classic case of a failing processor on the board that only malfunctioned once it reached a certain temperature. This highlights how a faulty ECM can mimic other component failures, making accurate diagnosis key.
Common Symptoms of a Failing ECM
- âś” Check Engine Light is on or flashing
- âś” Engine stalling or misfiring unexpectedly
- âś” Noticeable decrease in fuel economy
- âś” Car won’t start, but the battery and starter are good
- âś” Harsh or erratic automatic transmission shifting
- âś” Communication errors with diagnostic scan tools
- âś” Performance issues like hesitation or lack of power
Why Choose This 2006 STS Engine Control Module?
This isn’t just a part; it’s a complete solution. By providing us with your VIN during checkout, you eliminate the most complicated part of the repair. Our technicians will flash the module with the precise software your Cadillac STS requires. This ensures all onboard systems communicate correctly, and your engine operates exactly as the manufacturer intended. This module is compatible with a wide range of GM vehicles and is a direct replacement for multiple service numbers, including 12590032, 12602044, 12603530, 12605843, 12607096, and 19210737, guaranteeing broad applicability and proven reliability.
Installation is straightforward for any competent DIY mechanic or professional technician. Simply disconnect the battery, locate and remove your old ECM, install the new one, and reconnect the battery. In most cases, the vehicle will start and run correctly immediately. Please note that some vehicles may require a security relearn procedure, which can typically be done without special tools and instructions can be readily found online or in a service manual.
Frequently Asked Questions
Why do you need my VIN?
Your Vehicle Identification Number (VIN) is essential because it allows us to load the exact software and calibrations specific to your car’s engine, transmission, and factory options. This ensures perfect compatibility and function, making the module a true plug-and-play solution.
Will I need to do any additional programming after installation?
No. The module arrives pre-programmed and ready for installation. In some specific GM models, a simple security or anti-theft relearn procedure may be necessary, which typically involves a sequence of key turns. This does not require a dealer visit or specialized scan tools.
Is this a difficult part to replace myself?
For someone with basic mechanical skills, replacing an ECM is generally straightforward. It involves disconnecting the battery, unplugging the electrical connectors, and unbolting the module. The difficulty can vary depending on the module’s location. On the 2006 STS, it is located on the left-hand frame rail. Always disconnect the battery before starting any work.
How can I be sure my old ECM is the problem?
While the symptoms listed are strong indicators, it’s always best to have a proper diagnosis performed. This can involve checking for consistent trouble codes, testing power and ground signals at the ECM connector, and ruling out other potential causes like wiring issues or failed sensors. However, if multiple unrelated codes are present or if communication with the module is impossible, the ECM is the most likely cause.
Does this part fit vehicles other than the 2006 Cadillac STS?
Yes, absolutely. This ECM, part number 12630457, and its interchangeable service numbers fit a very wide array of GM vehicles from Buick, Chevrolet, Pontiac, Saturn, Hummer, Isuzu, and Saab across various years and models. Please refer to the detailed fitment list on this page to confirm compatibility with your specific vehicle.