Is Your Cadillac DTS Running Rough, Stalling, or Refusing to Start?
As a technician with over two decades of experience under the hood, I’ve seen my fair share of perplexing electrical issues. A faulty Engine Control Module (ECM) in a 2009-2011 Cadillac DTS can be one of the most frustrating. You might be chasing phantom sensor codes, dealing with a car that idles erratically, or worse, leaves you stranded. The ECM is the brain of your vehicle’s powertrain, and when it starts to fail, the symptoms can be widespread and confusing.
A Real-World Diagnosis Story: “A customer’s 2010 DTS came into my shop last month with a persistent P0606 (ECM/PCM Processor Fault) code and a no-start condition after it warmed up. We checked all the basics—power, grounds, and the CAN bus network—and everything seemed fine. The issue was intermittent, a classic sign of internal circuit board failure in the ECM. Swapping in a pre-programmed module like this one had the car running perfectly in under 30 minutes, saving the customer a tow to the dealer and hundreds in diagnostic and programming fees.”
The Direct Solution: A VIN-Programmed ECM Ready for Installation
This isn’t just a replacement part; it’s a complete solution. We take a genuine OEM ECM and flash it with the latest, most stable software updates directly from GM. By providing your Vehicle Identification Number (VIN) at checkout, you receive a module that is 100% configured for your specific 2009-2011 Cadillac DTS. This critical step ensures all systems, from the transmission to the anti-lock brakes, communicate correctly from the moment you turn the key.
Common Symptoms of a Failing 2009-2011 DTS Engine Control Module:
- âś” Check Engine Light with communication-related codes (e.g., U-codes, P0601, P0606).
- âś” Unexplained stalling or engine shutting off while driving.
- âś” Rough or erratic idle.
- âś” Complete no-start condition where the engine cranks but won’t fire.
- âś” Poor fuel economy and decreased engine performance.
- âś” Seemingly unrelated warning lights on the dashboard.
Plug-and-Play Installation: No Dealer Visit Required
You can perform this replacement yourself with basic hand tools. Our VIN programming service eliminates the need for expensive dealer-specific scan tools for setup. Just install the module, and you’re ready to go.
- Safety First: Disconnect the negative terminal from your vehicle’s battery and wait 10 minutes for the system capacitors to discharge.
- Locate the ECM: On the Cadillac DTS, the ECM is typically located in the engine bay, situated within the lower part of the air cleaner box assembly.
- Disconnect Connectors: Carefully release the locking tabs on the electrical wiring harnesses and pull them straight out from the old module. Inspect the connectors for any signs of corrosion or bent pins.
- Remove the Old Module: Unbolt the old ECM from its mounting bracket.
- Install the New Module: Secure your new, pre-programmed ECM in place and firmly reconnect the wiring harnesses until they click.
- Final Step: Reconnect the negative battery terminal. The vehicle may need to complete a security relearn procedure, which typically involves turning the key to the ‘ON’ position for 10-15 minutes. Your vehicle is now ready to start.
Expert Pro Tip: Clean Your Connections
Before installing your new ECM, take a moment to spray the vehicle’s harness connectors with a quality electronics cleaner. Use a small, soft brush (like a toothbrush) to gently scrub away any faint green or white powder—this is corrosion that creates resistance and can cause communication errors or even damage your new module. A clean connection is a reliable connection.
Guaranteed Fitment & Part Number Cross-Reference
This module, part number 12678512, is a direct replacement for a wide range of GM vehicles. It is interchangeable with the following service numbers, ensuring compatibility:
12636659, 12639300, 1263605, 12628993, 12628911, 12625453, 12622175, 12630464, 12678512
While this listing focuses on the 2009-2011 Cadillac DTS, it also fits models like the Buick Lucerne, Chevy Corvette, Hummer H3, and many more, making it a versatile and reliable solution for numerous GM applications. By providing your VIN, we guarantee it will be programmed correctly for your specific vehicle. Restore your car’s performance and reliability today.