Is Your Cadillac DTS Running Rough? The Solution is Here.
If you’re experiencing frustrating issues like a persistent check engine light, erratic engine behavior, stalling, or a complete no-start condition in your 2009, 2010, or 2011 Cadillac DTS, a failing Engine Control Module (ECM) is a very likely culprit. The ECM is the brain of your vehicle’s engine, managing everything from fuel mixture and ignition timing to transmission shifts. When it fails, it can cause a cascade of problems that are difficult to diagnose and can leave you stranded. This isn’t just an inconvenience; it’s a critical component failure that needs a reliable solution.
This replacement Engine Control Module, part number 12639300, is the definitive fix for these issues. We take the guesswork and hassle out of the repair process. Unlike a generic module from a parts store or a salvage yard, this unit is professionally programmed with the latest GM factory software updates specifically for your vehicle. All we need is your Vehicle Identification Number (VIN) during checkout. This ensures that when the part arrives, it’s a true plug-and-play solution, restoring your vehicle’s original performance, reliability, and fuel efficiency.
From the Diagnostic Bay
I once had a 2010 Cadillac DTS with the Northstar V8 come into the shop with a baffling intermittent stalling problem. The owner had already replaced the crankshaft position sensor and a few coils, but the issue persisted. Scans showed no consistent codes, just a few random communication errors. After hours of chasing wires, we decided to monitor the live data from the ECM. We noticed that the injector pulse width would suddenly drop to zero just before a stall. We swapped in a known-good, programmed ECM, and the car ran perfectly. The original module had an internal fault that only showed up under specific operating temperatures. It’s a classic example of how a faulty computer can mimic mechanical or sensor failures, making a pre-programmed 2009-2011 DTS Engine Control Module the most efficient and effective repair.
Symptoms of a Failing GM Engine Control Module
- ✔ Persistent and illuminated Check Engine Light (CEL).
- ✔ Engine stalling or shutting off unexpectedly while driving.
- ✔ Noticeable decrease in fuel economy.
- ✔ Rough idling, misfires, or hesitation during acceleration.
- ✔ The vehicle cranks but refuses to start.
- ✔ Automatic transmission shifting issues, such as harsh shifts or getting stuck in gear.
- ✔ Error messages on the dashboard related to engine systems or stability control.
- ✔ Failure to pass an emissions or smog test.
The Smart Choice for Your 2009-2011 DTS Engine Control Module
Choosing this pre-programmed ECM saves you significant time and money. There is no need for an expensive trip to the dealership for programming, which can often cost hundreds of dollars in labor alone. We handle the complex flashing process for you, ensuring all vehicle-specific parameters and security information are correctly loaded. Once installed, you may only need to perform a simple security relearn procedure (which takes about 10-15 minutes with just your key), and your Cadillac will be back to its smooth, powerful self. This module is a direct replacement for a wide range of GM service numbers, including 12636659, 12639300, 12628993, and more, ensuring broad compatibility across many models listed in our fitment guide.
Frequently Asked Questions
Do I need to get this module programmed by a dealer?
No. This is the primary benefit of our service. We program the Engine Control Module with the latest GM software using the VIN you provide before we ship it. This makes the installation process much simpler for you or your mechanic.
Where is the ECM located on my 2009-2011 Cadillac DTS?
On the Cadillac DTS and Buick Lucerne, the ECM is typically located inside the air cleaner box assembly in the engine bay. It’s essential to disconnect the battery before attempting to access or replace it. For other models, the location can vary, so consulting a service manual for your specific vehicle is always recommended.
What is a security relearn procedure and is it difficult?
The security relearn, or anti-theft relearn, is a simple procedure required on most GM vehicles to sync the new ECM with your car’s existing keys and security system. It typically involves turning the key to the ‘ON’ position for 10 minutes, then ‘OFF’ for 10 seconds, and repeating this cycle three times. No special tools are needed.
How do I provide my vehicle’s VIN?
You can enter your 17-digit VIN in the notes section during the checkout process. If you forget, you can also reply to your order confirmation email with the VIN. We cannot ship the module until we have this information.
Is this part compatible with other GM vehicles?
Yes, absolutely. While this is a perfect fit for the 2009-2011 Cadillac DTS, this ECM (part number 12639300 and its interchanges) is also the correct module for a wide variety of GM trucks and SUVs like the Chevy Colorado, GMC Canyon, Hummer H3, and other cars like the Corvette and Cadillac CTS. Please check the detailed fitment list on this page to confirm compatibility with your specific year, make, and model.