If you’re dealing with the headaches of a faulty transmission in your 2006-2007 Saturn Ion, you know how frustrating it can be. One minute it shifts fine, the next it’s banging into gear or refusing to shift at all. As a technician with over two decades of experience, I’ve seen countless drivers chase intermittent shifting problems, often replacing solenoids and sensors to no avail. The real culprit is frequently the Transmission Control Module (TCM)—the electronic brain in charge of your gearbox.
This T42 TCM, part number 24243901, is the definitive solution for your vehicle. We take the guesswork and high cost out of the repair by pre-programming it to your car’s specific Vehicle Identification Number (VIN). This means it arrives ready for a true plug-and-play installation, with no need for an expensive trip to the dealership for programming. It’s designed to restore the crisp, predictable shifting your Saturn Ion had from the factory, putting you back in confident control.
Diagnosing a Faulty Transmission Module
A failing TCM can mimic many other transmission issues, but there are tell-tale signs I look for in the shop. If your Saturn is showing any of these behaviors, a faulty module is the likely cause. This replacement 2006-2007 Ion TCM is engineered to resolve these exact problems.
- ✔ Harsh, erratic, or delayed gear shifts that make driving uncomfortable.
- ✔ The vehicle enters a ‘limp mode,’ often getting stuck in 2nd or 3rd gear.
- ✔ Your dashboard is lit up with a Check Engine Light or Transmission Warning Light, showing Diagnostic Trouble Codes (DTCs) like P0700, P0750, or other solenoid-specific codes.
- ✔ A noticeable drop in fuel economy as the transmission fails to operate efficiently.
- ✔ Complete failure to upshift or downshift, or a total loss of communication with the module.
A Technician’s Notebook: The Intermittent Ion
A customer brought in a 2007 Saturn Ion with a complaint that stumped two other shops: intermittent, bone-jarring shifts, but only after the car was fully warmed up. They had already replaced two shift solenoids. My scan tool showed a history of solenoid circuit codes, but they were intermittent. Instead of throwing more parts at it, I monitored the TCM data stream on a long test drive. Sure enough, as the engine bay heated up, the command signals from the TCM started dropping out. The internal circuit board on the original module had developed a hairline crack that only became an issue with thermal expansion. We installed one of our VIN-programmed T42 modules, and the problem was solved permanently. It’s a classic case where the module itself is the root cause, not the parts it controls.
DIY Installation: Get Your Saturn Shifting Smoothly in Minutes
One of the best features of this module is how simple it is to install. You don’t need a professional lift or specialized tools. For the 2006-2007 Saturn Ion, the TCM is conveniently located right in the engine compartment. This is a job most DIYers can complete in under 30 minutes.
- Safety First: Begin by disconnecting the negative terminal from your vehicle’s battery to prevent any electrical shorts and to help reset the system.
- Locate the Module: On your Saturn Ion, you’ll find the TCM located behind the driver’s side (LH) strut tower in the engine bay.
- Disconnect and Remove: Carefully unplug the electrical connectors from the old module. Press the release tabs firmly to avoid damaging them. 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 negative battery terminal. While the system may reset on its own, it’s best practice to use a basic OBD-II scan tool to clear any stored fault codes from the vehicle’s memory. Start the car and enjoy smooth shifting!
Verified Fitment Across the GM Family
While this is the perfect solution for your 2006-2007 Ion TCM replacement, this versatile T42 module is also a direct-fit for a wide range of other General Motors vehicles. Please confirm your model and year below. This part is interchangeable with service numbers 24242391, 24234503, 24252114, and others.
- ✔ Saturn: Ion (06-07), Vue (07-10), Aura (07-09)
- ✔ Chevrolet: Cobalt (06-10), HHR (06-11), Impala (06-11), Malibu (06-10), Monte Carlo (06-07), Silverado, Tahoe, Suburban, Avalanche, Express Van, Colorado (various years)
- ✔ Pontiac: G5 (07-10), G6 (06-10), Grand Prix (06-08), Pursuit (06)
- ✔ GMC: Sierra, Yukon, Savana Van, Canyon (various years)
- ✔ Buick: LaCrosse (06-09), Lucerne (06-11), Allure (06-09), Rendezvous (06-07), Rainier (06-07)
- ✔ And more: Including Cadillac DTS, Hummer H3, Saab 9-7X, and others from 2006-2014.
Frequently Asked Questions
What does ‘VIN Programmed’ mean for me?
It means we load your vehicle’s unique VIN into the module before shipping. This ensures it communicates perfectly with your car’s engine computer and other systems right out of the box, just like an OEM part from the dealer, but without the extra programming fee and appointment.
Will this fix a P0700 trouble code?
A P0700 code is a general fault request from the TCM to the main engine computer, telling it to turn on the check engine light. While P0700 itself isn’t specific, it’s almost always triggered by a deeper issue within the transmission’s control system. A failing TCM is a very common cause, so replacing it often resolves the P0700 and any related codes.
Is this a difficult part to replace myself?
Not at all. For the Saturn Ion, it’s one of the easier module replacements. It’s located in the engine bay and requires only basic hand tools to unbolt and swap. Because it’s pre-programmed, the most complex part of the job is already done for you.
Do I need to send my old part back?
No, there is no core charge for this module. You can keep your old part, which saves you the time and hassle of packaging and shipping it back to us.