Restore Your Montana’s Shifting Performance
Is your 2006-2009 Pontiac Montana experiencing harsh shifting, getting stuck in gear, or displaying a check engine light? These are classic signs of a failing Transmission Control Module (TCM). The TCM is the electronic brain of your automatic transmission, responsible for orchestrating gear changes, managing torque converter lockup, and monitoring system health. When it fails, drivability suffers, and you’re often left with an unreliable vehicle. This genuine OEM-quality T42 TCM, part number 24256960, is the definitive solution to restore your transmission’s smooth, factory-like operation.
From the Diagnostic Bay
We had a 2008 Pontiac Montana come into the shop with the classic P0700 code and complaints of banging into gear. The owner had already replaced two shift solenoids based on a forum recommendation, but the problem persisted. After a quick scan, we saw erratic data from the TCM. Instead of throwing more parts at it, we installed one of our pre-programmed T42 modules. The van was shifting perfectly within 30 minutes. It’s a common story: what seems like a major internal transmission failure is often just a faulty electronic module. Always check the TCM first to save time and money.
The Importance of a Programmed 2006-2009 Montana Transmission Module
Modern vehicles are complex, and the TCM is not a one-size-fits-all component. Each module must be specifically calibrated to your vehicle’s unique Vehicle Identification Number (VIN). Our process handles this for you. We flash the module with the latest GM software updates specific to your Montana, ensuring it communicates flawlessly with the Engine Control Module (ECM) and other vehicle systems right out of the box. This eliminates the need for expensive trips to the dealership for programming, making it a true plug-and-play repair for both professional technicians and DIY enthusiasts.
Symptoms of a Failing Transmission Control Module
- ✔ Harsh or erratic gear shifts, including banging or jerking into gear.
- ✔ The vehicle enters “limp mode,” often getting stuck in 2nd or 3rd gear.
- ✔ Check Engine Light or Transmission Warning Light is illuminated on the dashboard.
- ✔ Diagnostic Trouble Codes (DTCs) such as P0700, P0750, or other solenoid-related codes are present.
- ✔ Delayed engagement when shifting from Park to Drive or Reverse.
- ✔ Complete failure to upshift or downshift, leading to poor acceleration and fuel economy.
- ✔ Intermittent loss of communication with the TCM, causing unpredictable behavior.
Installation and Compatibility
Replacing the 2006-2009 Montana Transmission Module is a straightforward process. On your vehicle, the TCM is typically located on the driver’s side, attached to the strut tower. The installation can usually be completed in under an hour with basic hand tools. Simply disconnect the battery, unplug the electrical connectors from the old module, unbolt it, and install the new one in its place. Once the new module is connected and the battery is reconnected, the vehicle is ready to go. We recommend using a scan tool to clear any stored DTCs after installation for a clean slate.
This T42 TCM is a direct replacement for a wide range of GM vehicles and interchanges with numerous part numbers, including 24242391, 24234503, 24252114, 24230461, and many more. It’s the ideal part for a reliable, long-lasting repair that brings back the drivability and confidence you expect from your vehicle.
Frequently Asked Questions
What does a Transmission Control Module do in my Montana?
The TCM acts as the central computer for your automatic transmission. It processes data from various sensors (like vehicle speed and engine RPM) to control shift points, line pressure, and torque converter lockup, ensuring optimal performance, fuel efficiency, and smooth operation.
Is this module difficult to install on my 2006-2009 Montana?
No, installation is generally simple for someone with basic mechanical skills. On the Montana, it’s located on the LH strut tower, making it easily accessible in the engine bay. Since our modules come pre-programmed to your VIN, no special tools are needed for software flashing.
Why is VIN programming so important for this part?
VIN programming calibrates the TCM specifically to your vehicle’s factory settings and software. Without it, the module won’t communicate correctly with your engine and other systems, leading to continued shifting problems, error codes, or even a no-start condition. Our service saves you a costly trip to the dealer.
Will this TCM fix a P0700 trouble code?
A P0700 code is a general fault code indicating the TCM has detected a problem and has requested the Check Engine Light to be turned on. While this module often resolves the root cause of a P0700, it’s essential to scan for other transmission-specific codes (like P07xx) to confirm the diagnosis. A failing TCM is a very common cause for this code.
Do I need to return my old TCM? Is there a core charge?
No, there is no core charge for this part. You can keep your old module, which saves you the time, hassle, and expense of packaging and shipping it back.