Is Your GM 3.6L Vehicle Acting Possessed? Let’s Get It Fixed.
If your 2008-2009 Cadillac CTS, STS, or another GM 3.6L-powered vehicle like an Acadia or Traverse is suddenly stalling, refusing to start, or running rough with a Christmas tree of warning lights on the dash, you’re likely dealing with a failing Engine Control Module (ECM). As a technician with two decades of experience under the hood, I’ve seen this exact scenario play out hundreds of times. The ECM is the brain of your engine, and when it starts to falter, the symptoms can be confusing and frustrating.
A Real-World Story From The Shop
“A customer’s 2009 Acadia came in last week with these exact symptoms. It would crank but not start, and when it did, it ran horribly for a few seconds before stalling. The dashboard was lit up with a Check Engine Light and a ‘Service StabiliTrak’ message. The owner had already replaced a couple of sensors hoping for a cheap fix. My scan tool pulled a dozen communication codes (U-codes) and a P0606 ‘Internal Control Module Processor Error’. This immediately pointed me away from the sensors and directly to the ECM. After verifying power and ground to the module were solid, we confirmed the ECM itself was the culprit. This is a classic failure pattern for these units, often caused by years of heat cycles and vibration, especially where they’re mounted behind the fan shroud.”
Common Symptoms of a Failing 12623325 ECM
Your vehicle’s computer is a complex piece of hardware. When it fails, it doesn’t always just die completely. You might experience one or more of these issues, which can often be intermittent at first:
- โ Check Engine Light: Often with communication error codes (U-codes) or internal processor fault codes (like P0601, P0606).
- โ No-Start or Hard Starting: The engine cranks but won’t fire up, or takes an excessively long time to start.
- โ Engine Stalling: The vehicle may stall unexpectedly while driving or when coming to a stop.
- โ Poor Engine Performance: You might notice a significant loss of power, rough idling, hesitation, or poor fuel economy.
- โ Erratic Transmission Shifting: The ECM communicates with the transmission controller, and a fault can cause harsh or incorrect shifting.
- โ Other Warning Lights: Messages like ‘Service StabiliTrak’ or ‘Traction Control Off’ can be triggered by a faulty ECM.
The Direct Solution: A VIN-Programmed ECM
Don’t waste time and money chasing phantom sensor issues or buying a used module from a salvage yard that won’t work. A used ECM is locked to the original vehicle’s VIN and security system. Installing it will result in a no-start condition, requiring an expensive trip to the dealership for programmingโif they are even willing to program a used part.
This Engine Control Module is the definitive, hassle-free solution. Hereโs why:
- โ Programmed Specifically For You: Before we ship, we flash this module with the latest official GM software using the Vehicle Identification Number (VIN) you provide. This ensures it’s a perfect match for your vehicle’s specific configuration.
- โ Plug-and-Play Installation: Because the programming is done beforehand, this module is ready to be installed right out of the box. In most cases, no further security relearn procedures or costly dealer visits are required.
- โ Restores Original Performance: By replacing the faulty brain of your engine, you restore the precise fuel, spark, and transmission commands needed for smooth, reliable operation.
- โ Wide Compatibility: This module is a direct replacement for several part numbers, including 12623325, 12628387, 12605672, 12630594, and 19300016.
Confirm Your Fitment
Please verify this is the correct part for your vehicle. This module is compatible with the following models and options:
- โ 2008 Cadillac CTS: With 3.6L engine (VIN V, 8th digit), located in the RH front engine compartment.
- โ 2009 Cadillac CTS: With 3.6L engine (VIN V, 8th digit), located in the RH front engine compartment.
- โ 2008 Cadillac STS: With 3.6L engine, located on the RH side of the engine.
- โ 2009 Cadillac STS: With 3.6L engine, located on the RH side of the engine.
- โ 2009 GMC Acadia: Located behind the fan shroud.
- โ 2009 Chevrolet Traverse: Located behind the fan shroud.
- โ 2009 Saturn Outlook: Located behind the fan shroud.
- โ 2009 Buick Enclave: Located behind the fan shroud.
IMPORTANT: After your purchase, please send us a message with your vehicle’s 17-digit VIN. We cannot ship your part until we have this information to complete the programming process. Get your vehicle running right againโthe first time.