Is your Cadillac STS or other GM vehicle experiencing frustrating and unpredictable engine problems? Issues like a persistent check engine light, rough idling, stalling, or a complete no-start condition often point to a failing Engine Control Module (ECM). The ECM is the brain of your vehicle’s engine, managing everything from fuel injection and ignition timing to emissions control. When it fails, the entire system can become unreliable. This replacement ECM, part number 12628993, is the definitive solution to restore your vehicle’s performance, reliability, and drivability.
This isn’t just a part in a box. We provide a comprehensive service that ensures a seamless installation. Upon purchase, you will provide us with your vehicle’s Vehicle Identification Number (VIN). Our technicians will then program the module with the latest, most stable software updates directly from GM, specifically matched to your vehicle’s configuration. This critical step eliminates the need for expensive dealership programming and ensures that the module works perfectly with your vehicle’s systems right out of the box. It’s a true plug-and-play solution designed to get you back on the road quickly and confidently.
We had a 2009 Cadillac CTS-V come in with a complaint of intermittent stalling and a P0606 (Internal Control Module Processor Error) code. The owner had already replaced the throttle body and multiple sensors, chasing the problem for weeks. After confirming power and grounds to the ECM were solid, we knew the internal processor was failing. We installed one of these VIN-programmed modules, performed the quick 10-minute security relearn procedure, and the 6.2L powerhouse roared back to life, smoother than ever. It’s a reminder that sometimes the most complex symptoms originate from the central computer itself.
Diagnosing a Faulty 2009-2010 STS Engine Module
A failing ECM can manifest in various ways, often mimicking other component failures. If you’re experiencing any of the following symptoms, your engine computer may be the culprit. A comprehensive diagnostic scan is always recommended, but these are strong indicators that your module needs attention.
- ✔ Check Engine Light: The light is illuminated, often with communication-related trouble codes (U-codes) or internal processor fault codes (P06xx series).
- ✔ Engine Stalling or Misfiring: The engine may stall unexpectedly while driving or at idle, and you might experience random misfires on one or more cylinders.
- ✔ No-Start Condition: The engine cranks but refuses to start, often due to the ECM not firing the injectors or ignition coils.
- ✔ Poor Fuel Economy: A faulty module can’t properly calculate the air-fuel mixture, leading to a noticeable drop in MPG.
- ✔ Failed Emissions Test: Incorrect engine management will almost certainly lead to a failed smog or emissions inspection.
- ✔ Erratic Transmission Behavior: The ECM communicates with the transmission controller, and a fault can cause harsh shifting or other transmission issues.
- ✔ Loss of Communication: A scan tool may be unable to communicate with the engine control module, a definitive sign of failure.
Guaranteed Compatibility and Simple Installation
This module is a direct replacement for a wide range of General Motors vehicles, ensuring a perfect fit and function. It is fully interchangeable with the following service numbers: 12636659, 12639300, 1263605, 12628993, 12628911, 12625453, 12622175, 12630464, and 12678512. Please verify your part number or consult our extensive fitment list below to confirm compatibility with your exact make, model, and engine option. Because we program it to your VIN, you can be certain you’re receiving the correct part with the correct software for your vehicle’s specific needs.
While the module is plug-and-play, some GM vehicles may require a simple security relearn procedure after installation. This can typically be done without any special tools and involves a series of key cycles. Instructions are readily available and easy to follow, ensuring a smooth and successful repair.
Frequently Asked Questions
Do I need to send my old ECM to you?
No, there is no core charge or need to send in your old part. This is a direct purchase, and the module we send you is yours to keep.
What is VIN programming?
VIN programming involves loading your vehicle’s specific identification number and factory-installed options into the module. This ensures the ECM communicates correctly with all other computers in your car, such as the transmission controller and anti-lock brake system.
How do I provide my VIN?
After you place your order, you can send us a message with your 17-digit VIN. We cannot ship the part until we receive this information, as the programming is a critical part of the order.
Will this fix my specific problem?
This module will correct issues directly caused by a faulty ECM. While the symptoms listed are common indicators, we always recommend a proper diagnosis by a qualified mechanic to confirm the ECM is the point of failure before ordering.
Is any other programming needed after installation?
In most cases, no. The module arrives ready to install. However, some GM vehicles require a security or anti-theft relearn procedure, which can typically be performed by the owner in about 10-15 minutes with just the ignition key.