Is your 2006-2009 Pontiac Montana struggling with harsh shifts, delayed gear engagement, or a frustrating check engine light? Before you worry about a costly transmission overhaul, the problem is often a faulty Transmission Control Module (TCM). As the electronic brain of your automatic transmission, a failing TCM can cause a host of drivability issues that can leave you stranded. This T42 TCM, part number 24235754, is the definitive solution, arriving expertly programmed to your vehicle’s VIN for a true plug-and-play fix.
Over my two decades in automotive diagnostics, I’ve seen countless drivers spend a fortune chasing down what they think are internal transmission failures. More often than not, especially on these GM platforms, the root cause is electronic. This module directly replaces the original, restoring precise communication between the engine and transmission. It manages everything from shift points and line pressure to torque converter lockup, ensuring your vehicle performs exactly as the manufacturer intended. By installing our pre-programmed module, you bypass the expensive and time-consuming trip to the dealership for programming, saving you hundreds of dollars and significant downtime.
Case Study: A Tricky Diagnosis
A customer brought in a 2008 Uplander (which uses the same platform as the Montana) with classic symptoms: it was stuck in 3rd gear (limp mode) and had a P0700 code. The previous shop wanted to replace the entire transmission. I hooked up my scan tool and saw erratic data from the shift solenoids. Instead of just replacing parts, I checked the TCM connectors—they were clean. The real issue, which I’ve seen dozens of times, was internal failure within the original TCM’s driver circuits. We installed one of our pre-programmed modules, and in under 30 minutes, the van was shifting perfectly. The customer saved over two thousand dollars by correctly identifying the electronic failure first.
Is Your Minivan Showing These Warning Signs?
A failing TCM isn’t always obvious. If you’re experiencing any of the following, this module is your likely solution. Ignoring these symptoms can lead to permanent transmission damage.
- ✔ Harsh, banging shifts or erratic gear hunting.
- ✔ The transmission feels like it’s slipping or hesitating to engage a gear.
- ✔ Your vehicle is stuck in one gear (often called ‘limp mode’).
- ✔ Check Engine Light or Transmission Warning Light is on with codes like P0700, P0750-P0758 (solenoid circuits), or other transmission-related DTCs.
- ✔ A sudden drop in fuel economy or the transmission overheating.
- ✔ Complete loss of communication with the transmission.
Simple DIY Installation for Your Pontiac Montana
You don’t need to be a professional mechanic to complete this job. The 2006-2009 Montana Transmission Module is designed for a straightforward swap. On your Pontiac Montana, it’s typically located on the driver’s side strut tower, making it easily accessible in the engine bay.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery to prevent electrical shorts and reset the system.
- Locate the Module: Find the old TCM mounted on the LH (driver’s side) strut tower in the engine compartment.
- Disconnect and Remove: Carefully unplug the electrical connectors. Note the tab locations to avoid damage. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCM into place and securely reconnect the electrical harnesses. You should hear a ‘click’ as they lock in.
- Final Steps: Reconnect the battery terminal. Start the vehicle and let it idle for a few minutes. While our programming resolves most codes, it’s good practice to use a basic OBD2 scanner to clear any stored DTCs. No core charge means you can keep or discard your old part without any hassle.
Verified Vehicle Compatibility
This T42 TCM is a direct replacement for part number 24235754 and is interchangeable with many other GM service numbers. While this page focuses on the Pontiac Montana, it also provides guaranteed fitment for a wide range of GM vehicles, including:
- Pontiac: Montana (06-09), G6 (06-10), Grand Prix (06-08), Pursuit (06)
- Chevrolet: Uplander (06-09), Impala (06-11), Monte Carlo (06-07), Cobalt (06-10), HHR (06-11), and many trucks/SUVs.
- Buick: Terraza (06-07), Rendezvous (06-07), LaCrosse (06-09), Allure (06-09)
- Saturn: Relay, Vue, Ion, Aura
Please use the fitment checker to confirm compatibility with your specific year and model.
Frequently Asked Questions
Do I need to take my van to the dealer after installation?
No. This module is delivered pre-programmed to your vehicle’s specific VIN. This ensures it communicates perfectly with your vehicle’s other computers right out of the box, eliminating the need for any additional dealership programming.
Is this a difficult part to install myself?
Not at all. For a Pontiac Montana, the TCM is located on the driver’s side strut tower and is very accessible. With basic hand tools, most DIYers can complete the swap in under 30 minutes. Just disconnect the battery, swap the module, and reconnect.
Will this fix a P0700 Diagnostic Trouble Code?
Yes, in many cases. The P0700 code is a general fault code indicating the TCM has detected a problem. Often, the problem is the TCM itself. Replacing a faulty module with this pre-programmed unit will resolve the underlying issue causing the P0700 and related specific codes (like for solenoids).
What is the difference between a TCM and a PCM/ECM?
The TCM (Transmission Control Module) specifically controls the automatic transmission’s functions. The PCM (Powertrain Control Module) or ECM (Engine Control Module) manages the engine. On many modern vehicles, they are separate units that must communicate correctly. This part is solely for the transmission.
Is there a core charge for my old part?
No. We do not require you to send your old module back. There is no core charge, making the process simpler and faster for you.