End Frustrating Shifting Problems in Your Pontiac Montana
If your 2006, 2007, 2008, or 2009 Pontiac Montana is suffering from harsh shifting, getting stuck in gear, or has an illuminated check engine light, a failing Transmission Control Module (TCM) is the most likely culprit. As a mechanic with over two decades of experience, I’ve seen these T42 modules cause countless headaches for owners. The TCM is the brain of your automatic transmission, and when it fails, it can make your reliable family vehicle feel unpredictable and unsafe. This isn’t a problem you can ignore, as it can lead to further transmission damage and costly repairs down the line.
We offer a dependable and straightforward solution: a high-quality replacement 2006-2009 Montana TCM, part number 24235340. The biggest advantage we provide is our expert VIN programming service. Simply give us your vehicle’s VIN during checkout, and we’ll program the module with the latest GM software before it even ships. This means it arrives at your door ready for a true plug-and-play installation, saving you a trip to the dealership and hundreds of dollars in programming fees.
A Technician’s Notebook: The Ghost in the Transmission
I remember a 2008 Montana that came into the shop with a very frustrating, intermittent issue. The owner complained of random hard shifts, especially after driving for 20-30 minutes. We’d scan it, find no active codes, and the test drive would be perfect. The problem only happened when the engine bay got hot. After checking wiring and grounds, we focused on the TCM. On these vans, the TCM is mounted on the LH strut tower, where it’s exposed to significant heat cycles. We swapped in a pre-programmed module, and the problem vanished instantly. It’s a classic case of heat-induced failure in these electronic components.
Common Signs Your Montana’s TCM is Failing
A failing TCM can manifest in several ways. If you’re experiencing any of the following, it’s time to consider a replacement. In my shop, these are the tell-tale signs that point directly to a bad module:
- âś” Harsh, erratic, or delayed gear shifts.
- âś” Vehicle is stuck in “limp mode” (usually 2nd or 3rd gear).
- âś” Check Engine Light or Transmission Warning Light is on.
- âś” Diagnostic Trouble Codes (DTCs) are present, such as P0700, P0750, or other solenoid-related faults.
- âś” The transmission refuses to upshift or downshift properly.
- âś” A noticeable drop in fuel economy.
Your Step-by-Step Guide to a Quick Installation
One of the best parts about this repair is how accessible it is for a DIY mechanic. For the Pontiac Montana, the job is especially straightforward. You can have your van back to shifting smoothly in under 30 minutes with basic hand tools.
- Safety First: Before you begin, disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and to help reset the system.
- Locate the TCM: On your 2006-2009 Montana, the TCM is located in the engine bay, mounted directly to the driver’s side (LH) strut tower. It’s an easily accessible silver box with electrical connectors.
- Disconnect and Remove: Carefully unplug the electrical harnesses from the old module. Press the release tabs firmly. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt your new, pre-programmed TCM into place. Securely plug in the electrical connectors until they click, ensuring a solid connection.
- Final Steps: Reconnect the negative battery terminal. Start the vehicle and let it run for a few minutes. While not always necessary, using a basic OBD2 scan tool to clear any stored fault codes is a good final practice.
Verified Vehicle Compatibility List
This T42 module is a direct fit for the following vehicles, specifically the 2006-2009 Montana TCM. It also interchanges with a wide range of other GM vehicles, making it a versatile and reliable part. Always confirm your part number (24235340) or check the list below.
- Pontiac Montana: 2006-2009 (LH strut tower)
- Chevrolet Uplander: 2006-2009 (LH strut tower)
- Buick Terraza: 2006-2007 (LH strut tower)
- Saturn Relay: 2006-2007 (LH strut tower)
- And many other GM cars, trucks, and SUVs from 2006-2014. See the full fitment list for details. This module is interchangeable with part numbers 24252114, 24234503, 24230461, and more.
Frequently Asked Questions
Does this module require any additional programming?
No. This module is expertly programmed to your vehicle’s VIN before shipping. It is a true plug-and-play solution, saving you a trip to the dealership.
Is this a difficult part to install myself?
Not at all. For the Pontiac Montana, the TCM is located on the driver’s side strut tower and is very easy to access. With basic tools, most people can complete the installation in under 30 minutes.
What is a core charge?
A core charge is a deposit that is returned to you when you send back your old part. We do not have a core charge on this item, so you can keep your old module without any hassle.
What kind of warranty comes with this part?
This transmission control module is backed by our one-year, hassle-free warranty, giving you peace of mind with your purchase.
Will this fix a P0700 trouble code?
A P0700 code is a general transmission fault request from the TCM to the ECM to turn on the check engine light. While this module often resolves the underlying issue causing the P0700, it’s important to scan for more specific P-codes (like P0751, P0756, etc.) to confirm the diagnosis.