Restore Peak Performance to Your Cadillac DTS
If you’re dealing with frustrating engine problems in your 2009-2011 Cadillac DTS—like erratic idling, stalling, a persistent check engine light, or a dreaded no-start condition—a failing Engine Control Module (ECM) is often the culprit. As a technician with over two decades of experience under the hood, I’ve seen firsthand how a faulty ECM can turn a reliable luxury vehicle into a source of constant headaches. This isn’t just a part; it’s the central computer for your engine, and when it fails, nothing works right. This replacement ECM is the dependable, straightforward solution you need to get your Cadillac running smoothly again.
A Technician’s Notebook: The Intermittent No-Start Cadillac
A few months back, a 2010 Cadillac DTS was towed into my bay with a classic, frustrating problem: it would start and run perfectly for days, then suddenly refuse to start at all. The owner had already replaced the battery and checked the starter. When I connected my scan tool, I found a slew of communication loss codes (U-codes) pointing to the ECM. After verifying the wiring and power/ground circuits to the module were solid, it was clear the ECM itself was failing internally. The customer was worried about a massive dealership bill for a new computer and programming. We provided a VIN-programmed module just like this one. The swap took less than 30 minutes, and the car fired up on the first try. It’s been on the road without a single issue since. This is the power of a reliable, pre-programmed part.
Is Your Cadillac Exhibiting These ECM Failure Signs?
A failing ECM can manifest in various ways. If you’re noticing any of the following, it’s a strong indicator that the engine’s computer needs attention. Look out for:
- ✔ Check Engine Light is on with codes like P0601, P0606 (Internal Control Module Processor Error).
- ✔ Vehicle refuses to start or is very difficult to start.
- ✔ Stalling or rough idling for no apparent reason.
- ✔ Noticeable decrease in fuel economy.
- ✔ Poor engine performance, hesitation, or misfires.
- ✔ Communication errors with scan tools or other modules (U-codes).
- ✔ Transmission shifting issues or other electronic problems.
The Advantage of a VIN-Programmed Module
The biggest hurdle in replacing an ECM has always been the expensive and time-consuming programming required at a dealership. We eliminate that step completely. When you provide your Vehicle Identification Number (VIN) during checkout, we flash this 2009-2011 DTS ECM with the latest, most stable software directly from GM for your specific vehicle. This ensures all factory settings, security information (anti-theft), and engine parameters are perfectly matched. It arrives at your door ready for installation, saving you time, money, and a trip to the dealer.
A Straightforward Guide to Installation
- ✔ Safety First: Always disconnect the negative terminal from your vehicle’s battery before beginning any electronic work.
- ✔ Locate the ECM: On the Cadillac DTS and Buick Lucerne, the ECM is typically found within the lower part of the air cleaner box assembly. You will need to remove the air filter cover and filter to access it.
- ✔ Disconnect Connectors: Carefully unclip and remove the electrical connectors from the old module. Inspect the pins for any corrosion or damage.
- ✔ Remove the Old Module: Unbolt the old ECM from its mounting bracket and remove it from the vehicle.
- ✔ Install the New Module: Seat your new, pre-programmed ECM into the mounting bracket and secure it. Reconnect the electrical connectors, ensuring they click firmly into place.
- ✔ Final Steps: Reassemble the air cleaner box and reconnect the negative battery terminal. Start the vehicle and let it idle for a few minutes. In most cases, no further action is needed, but some vehicles may require a simple throttle body relearn procedure, which can be found in your owner’s manual or online.
Verified Vehicle Compatibility
This ECM, part number 12639300, is a direct replacement for a wide range of GM vehicles. It is interchangeable with service numbers 12636659, 1263605, 12628993, 12628911, 12625453, 12622175, 12630464, and 12678512. While this listing is focused on the 2009-2011 DTS ECM, it also fits the following models. Please verify your specific part number or contact us with your VIN to confirm.
- ✔ Cadillac DTS: 2009-2011
- ✔ Buick Lucerne: 2009-2011 (4.6L)
- ✔ Cadillac CTS: 2009 (6.2L)
- ✔ Cadillac SRX: 2009 (4.6L)
- ✔ Cadillac STS: 2009-2010 (4.4L, 4.6L)
- ✔ Cadillac XLR: 2009
- ✔ Chevy Colorado / GMC Canyon: 2009-2012 (2.9L, 3.7L)
- ✔ Chevy Corvette: 2009 (ZR1)
- ✔ Chevy Trailblazer / GMC Envoy: 2009 (5.3L, 6.0L)
- ✔ Hummer H3: 2009-2010 (3.7L)
- ✔ Saab 9-7X: 2009
Frequently Asked Questions
Why do you need my VIN?
Your VIN is essential for us to program the ECM with the correct GM software for your vehicle’s specific options, engine, and transmission. This ensures perfect compatibility and function without needing a trip to the dealership.
Is this a plug-and-play part?
Yes, because we program it to your VIN before shipping, it is designed to be a direct-fit, plug-and-play solution. In some rare cases, a security or crank relearn procedure may be required, which can be done with a capable scan tool or by a local mechanic.
Will this fix my check engine light?
If the check engine light is caused by an internal failure of the ECM (like codes P0601-P0606), then yes, this part will resolve the issue. It’s crucial to properly diagnose the vehicle first to ensure the ECM is the root cause of the problem.
What is the difference between this and a used part from a junkyard?
A used part from a junkyard will be programmed to the donor vehicle and will not work in your car without being reprogrammed. Our module comes with fresh, updated GM software specifically for your VIN, ensuring it works correctly right out of the box.