Is Your Pontiac Montana Experiencing Engine Troubles?
If your 2008-2009 Pontiac Montana is suffering from a persistent check engine light, poor fuel mileage, erratic shifting, or a frustrating no-start condition, a failing Engine Control Module (ECM) is likely the culprit. As the central computer of your vehicle, the ECM manages everything from fuel injection and ignition timing to transmission shifting and emissions control. When it fails, the symptoms can be widespread and difficult to diagnose. This direct-replacement ECM, part number 12602044, is the definitive solution to restore your vehicle’s factory performance and reliability.
From the Diagnostic Bay
We recently had a 2009 Montana SV6 in the shop with a strange combination of issues: harsh 2-3 shifts and a check engine light with a U0100 ‘Lost Communication with ECM/PCM’ code. The owner had already replaced several sensors to no avail. After hooking up our diagnostic tools, we noticed the ECM would intermittently drop its data stream. This tiny glitch was causing chaos for the transmission and other modules. We installed this exact, pre-programmed ECM, performed a quick security relearn, and the van drove like new. It’s a classic example of how a faulty computer can mimic a major mechanical failure.
Symptoms of a Failing 2008-2009 Montana ECM
- ✔ Persistent Check Engine Light (CEL) that won’t clear.
- ✔ Unexplained drop in fuel economy.
- ✔ Engine stalling, hesitating, or running rough.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Misfire codes even after replacing spark plugs and coils.
- ✔ Vehicle cranks but refuses to start.
- ✔ Communication errors with diagnostic scan tools.
A True Plug-and-Play Solution
Don’t waste time and money at the dealership. This module is not just a part; it’s a complete service. When you place your order, you provide us with your vehicle’s VIN. Our technicians then flash the module with the latest, most stable GM-certified software specific to your Montana. This ensures perfect compatibility and function right out of the box. This process handles all the critical programming, so you can avoid the high costs and scheduling hassles of a dealership service appointment.
This unit is a genuine OEM part and is a direct replacement for service numbers 12590032, 12602044, 12603530, 12605843, 12607096, 12630457, and 19210737. While this listing is focused on the 2008-2009 Pontiac Montana, this versatile module also fits a wide array of other GM vehicles, including the Chevrolet Impala, Buick Allure, GMC Envoy, and many more, as detailed in the fitment list.
Frequently Asked Questions
Do I need to get this ECM programmed?
No. We handle all the programming for you before shipment. Simply provide your vehicle’s VIN during checkout, and the module will arrive ready for installation, loaded with the latest GM software for your specific vehicle.
Where is the ECM located on a 2008-2009 Pontiac Montana?
On the 2008-2009 Pontiac Montana, the Engine Control Module is typically located in the engine compartment on the driver’s side (LH side).
What is a VIN and why do you need it?
The VIN (Vehicle Identification Number) is a unique 17-digit code for your specific vehicle. It contains information about the make, model, year, and factory-installed options. We use the VIN to load the exact correct software and calibrations for your vehicle’s engine, transmission, and options package, ensuring perfect operation.
Will this fix my check engine light?
If the check engine light is caused by a faulty ECM, then yes, this part will resolve the issue. However, it’s always recommended to have the codes professionally diagnosed to ensure the ECM is the root cause and not another sensor or component.
Is any special procedure required after installation?
In many cases, the vehicle will start and run immediately. However, some GM vehicles may require a simple, key-on/key-off security relearn procedure to sync the new ECM with the vehicle’s anti-theft system. This procedure does not require special tools and instructions can be easily found online or in a service manual.