Restore Your Saturn’s Drivability and End Transmission Headaches
If your 2007-2009 Saturn Aura is suffering from erratic shifting, getting stuck in gear, or throwing transmission-related check engine lights, you’re not just dealing with an annoyance—you’re facing a critical failure that compromises safety and performance. As a technician with over two decades of experience, I’ve seen countless GM vehicles sidelined by a faulty Transmission Control Module (TCM). The T42 module, in particular, is the electronic brain of your automatic transmission. When it fails, communication breaks down, leading to the frustrating and often unpredictable symptoms you’re experiencing. This isn’t just a part; it’s the command center for every gear change, and replacing it is the key to getting your car back to factory-smooth operation.
This replacement T42 TCM, part number 24238856, is the definitive solution for your vehicle. What sets our modules apart is the crucial pre-programming service. We flash the module with your car’s specific Vehicle Identification Number (VIN) and the latest GM software before it even ships. This means you can skip the expensive and time-consuming trip to the dealership for programming. It arrives at your door ready for a true plug-and-play installation, making it an ideal repair for both seasoned mechanics and determined DIYers looking to save hundreds of dollars.
Case Study: The ‘Limp Mode’ Saturn Aura
A customer brought in a 2008 Saturn Aura that was perpetually stuck in 3rd gear—a classic ‘limp mode’ scenario. They had already spent a fair amount of money replacing a couple of shift solenoids, hoping for an easy fix, but the problem persisted. The scanner was showing a general transmission fault code, P0700. In my shop, this code is often the first clue pointing towards the TCM. After verifying the wiring was intact, we swapped in a pre-programmed T42 module. The entire job took less than an hour, and on the first test drive, the transmission shifted perfectly through all gears. The P0700 code was gone for good. This is a textbook example of how a failing 2007-2009 Aura TCM can mimic other issues, making a direct replacement the most effective and efficient repair.
Is Your Saturn Aura Showing These Transmission Warning Signs?
- ✔ Harsh, clunky, or delayed gear shifts that make driving uncomfortable.
- ✔ The vehicle refuses to shift out of a single gear (limp mode), severely limiting speed.
- ✔ An illuminated Check Engine Light or Transmission Warning Light on your dash.
- ✔ Diagnostic Trouble Codes (DTCs) stored in the system, such as P0700, P0750, or other solenoid-specific faults.
- ✔ A noticeable drop in fuel economy as the transmission operates inefficiently.
- ✔ Complete loss of communication with the module, resulting in a no-start or no-shift condition.
A Straightforward DIY Guide to Replacing Your TCM
Replacing the 2007-2009 Aura TCM is a manageable job for most home mechanics. For the Saturn Aura, the module is typically located on the front of the left-hand frame rail. Always consult a vehicle-specific repair manual if you are unsure.
- Safety First: Before you begin, disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and to help reset the onboard systems.
- Locate the Module: Find the TCM on the LH frame rail in the front of the engine compartment. It’s a silver box with electrical connectors.
- Disconnect and Remove: Carefully unplug the electrical harnesses. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the 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. While the module is plug-and-play, it’s best practice to use a basic OBD2 scan tool to clear any lingering fault codes from the computer’s memory.
Verified Vehicle Compatibility
This T42 TCM is a direct replacement for part number 24238856 and is interchangeable with a wide range of other GM part numbers. While this page focuses on the 2007-2009 Aura TCM, this module also fits many other vehicles. Please verify your part number or consult the fitment list below.
- Saturn Aura: 2007-2009 (Transmission; LH frame rail front)
- Buick Allure / LaCrosse: 2006-2009 (Transmission; lower air cleaner housing)
- Chevrolet Cobalt / Pontiac G5 / Pursuit: 2006-2010 (Transmission; LH strut tower)
- Chevrolet HHR: 2006-2011 (Transmission; LH engine compartment)
- Chevrolet Impala / Monte Carlo: 2006-2011 (Transmission; lower air cleaner housing)
- Chevrolet Malibu: 2006-2010 (Transmission; LH frame rail)
- Pontiac G6: 2006-2010 (Transmission; LH strut tower)
- …and many other GM models from 2006-2014. Please check the comprehensive list provided in the product details.
Frequently Asked Questions
Do I need to do any programming after installation?
No. This module is delivered to you fully programmed to your vehicle’s VIN. It is ready for installation right out of the box, with no need for a trip to the dealer or a special scan tool for programming.
What is a ‘core charge’ and do you require one?
A core charge is a deposit that is returned to you when you send back your old part. We do not require a core charge for this TCM, so you can keep your old part without any hassle or extra steps.
Will this fix a P0700 trouble code?
A P0700 code is a generic fault code indicating the TCM has detected a problem. While this module often resolves the root cause of a P0700, it’s important to ensure other transmission components (like wiring or solenoids) are in good working order. However, if your symptoms align with TCM failure, this part is the most likely solution.
Where is the TCM located on my 2008 Saturn Aura?
On the 2007-2009 Saturn Aura, the Transmission Control Module is typically mounted on the front of the left-hand (driver’s side) frame rail inside the engine bay.