If your 2006-2007 Saturn ION is suffering from harsh shifting, getting stuck in gear, or throwing transmission codes, you’re not dealing with a failing transmission—you’re likely facing a faulty Transmission Control Module (TCM). As a technician with over two decades of experience, I’ve seen countless drivers worry about expensive transmission rebuilds when the real culprit is this electronic brain. This replacement T42 TCM, part number 24230461, is the direct, reliable solution to restore your vehicle’s performance and peace of mind.
This isn’t just a part; it’s a complete fix. We pre-program each module to your vehicle’s specific VIN before shipping. This means no expensive trips to the dealership for programming, no special tools, and no headaches. It arrives ready for a straightforward, plug-and-play installation, allowing you to get your Saturn ION driving smoothly again in under an hour. This module is the key to resolving those frustrating communication errors and erratic behaviors that make your car feel unpredictable.
Case Study: A Tricky Diagnosis
A customer brought in a 2007 Saturn ION with a complaint that stumped a couple of other shops. The car would intermittently refuse to shift out of 2nd gear and the check engine light would flash on and off. They had already replaced two shift solenoids based on the codes, but the problem persisted. After a quick scan, I saw the classic P0700 (Transmission Control System Malfunction) and intermittent solenoid circuit codes. Experience told me this wasn’t a mechanical issue inside the transmission but an electrical one. The root cause was a failing 2006-2007 ION Transmission Module that was sending erratic signals. Once we swapped in a VIN-programmed module, the codes cleared, and the car shifted perfectly. It’s a textbook example of how this single component can mimic a major transmission failure.
Common Signs of a Failing Saturn ION TCM
A faulty TCM can cause a range of symptoms that are often misdiagnosed. If you’re experiencing any of the following, this module is your likely solution:
- ✔ Harsh, delayed, or unpredictable gear shifts.
- ✔ The vehicle enters “limp mode,” getting stuck in a single gear (usually 2nd or 3rd).
- ✔ An illuminated Check Engine Light or Transmission Warning Light.
- ✔ Diagnostic Trouble Codes (DTCs) such as P0700, P0750, P0753, P0758, or other solenoid-related faults.
- ✔ A noticeable decrease in fuel economy due to inefficient shifting.
- ✔ Complete loss of communication with the TCM, preventing shifting altogether.
A Straightforward Guide to Installation
One of the best features of this part is its simple installation, making it a perfect job for a DIY enthusiast. You can have your car back to normal in your own driveway.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and to help reset the system.
- Locate the Module: On the 2006-2007 Saturn ION, the TCM is conveniently located in the engine bay, right behind the driver’s side (LH) strut tower.
- Disconnect and Remove: Carefully unplug the electrical connectors from the old module. 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. Ensure they click into place.
- Final Steps: Reconnect the battery terminal. Start the vehicle and allow it to idle for a few minutes. While not always necessary, using a basic OBD2 scanner to clear any stored fault codes is good practice.
Verified Vehicle Compatibility
This T42 Transmission Control Module is a direct replacement for part number 24230461 and other interchangeable numbers. It is specifically programmed for the following vehicle:
- ✔ Saturn ION: 2006-2007 (Transmission; located behind LH strut tower)
It is also compatible with a wide range of other GM vehicles. Please verify your part number or contact our expert team to ensure perfect fitment.
Frequently Asked Questions
Do I need to have this module programmed by a dealer?
No. We handle all the programming for you. Simply provide your vehicle’s VIN during checkout, and the module will arrive ready for immediate installation, saving you hundreds in dealership fees.
Is this a difficult part to install myself?
Not at all. For the Saturn ION, the TCM is easily accessible in the engine bay. With basic hand tools, most people can complete the swap in under 30 minutes. Our installation guide above provides all the steps you need.
What is a core charge? Do I need to send my old part back?
There is absolutely no core charge for this module. You can keep your old part, so there’s no hassle with return shipping or waiting for a refund.
Will this fix a P0700 trouble code?
Yes, in many cases. A P0700 code is a general fault code indicating the TCM has detected a problem. If the root cause is the module itself (a very common failure), replacing it with our pre-programmed unit will resolve the code and the underlying shifting issues.