Is Your Saturn Ion Shifting Erratically or Stuck in Gear?
If you’re experiencing frustrating and unpredictable transmission behavior in your 2006-2007 Saturn Ion, a failing Transmission Control Module (TCM) is the most likely culprit. Symptoms like harsh gear changes, delayed engagement from park to drive, or the dreaded “limp mode” can make your daily drive a stressful experience. A lit Check Engine Light, often with codes like P0700, points directly to a communication breakdown between your engine and transmission—a problem managed entirely by the TCM.
This T42 Transmission Control Module, service part 24243921, is the definitive solution to restore your vehicle’s performance. As the electronic brain of your automatic transmission, the TCM is responsible for executing precise shifts, controlling torque converter lockup, and ensuring overall powertrain efficiency. When it fails, the complex mechanics of your transmission can no longer operate in sync, leading to poor performance, decreased fuel economy, and potentially severe mechanical damage if left unaddressed.
From the Diagnostic Bay
We had a 2007 Saturn Ion come into the shop that was stuck in 3rd gear. The owner had already replaced two shift solenoids based on a generic code reader’s output, but the problem persisted. After a quick scan with professional equipment, we saw clear communication fault codes pointing to the TCM. The internal circuits had failed, preventing the module from commanding the new solenoids. We installed one of our VIN-programmed T42 modules, cleared the codes, and the car was shifting perfectly within 30 minutes. It’s a classic case where replacing the brain, not just the components it controls, is the correct fix.
Why Choose Our Programmed Saturn Ion TCM?
Don’t settle for a generic, unprogrammed module that requires an expensive trip to the dealership for calibration. Our T42 TCMs are meticulously programmed to your vehicle’s specific Vehicle Identification Number (VIN) before they ship. This critical step ensures that the module arrives with the latest GM software updates and is perfectly matched to your Ion’s factory settings. The result is a true plug-and-play installation that restores original performance and resolves persistent diagnostic trouble codes right out of the box.
Symptoms of a Failing 2006-2007 Saturn Ion TCM
- ✔ Harsh, jerky, or delayed gear shifts.
- ✔ Vehicle gets stuck in a single gear (limp mode).
- ✔ Check Engine Light or Transmission Warning Light is illuminated.
- ✔ Diagnostic Trouble Codes (DTCs) such as P0700, P0750, or other solenoid-related faults.
- ✔ Inability to upshift or downshift properly.
- ✔ A noticeable decrease in fuel efficiency.
- ✔ Complete loss of transmission engagement.
Simple Installation, Lasting Results
Replacing the TCM on your Saturn Ion is a straightforward process. The module is located behind the driver-side strut tower in the engine compartment. Simply disconnect the battery, unplug the electrical connectors from the old module, unbolt it, and install the new one in its place. Once the new module is connected and the battery is reconnected, the vehicle is ready to go. We recommend using a basic scan tool to clear any stored codes after installation. Built to strict OEM standards and backed by a one-year warranty, this module is engineered for long-term reliability.
This module is a direct replacement for a wide range of GM vehicles utilizing the 4-speed automatic transmission (4L60E, 4L65E, etc.) and interchanges with numerous part numbers, including 24252114, 24234503, 24240400, and 24243921. Restore the smooth, reliable performance your vehicle was built for.
Frequently Asked Questions
What does this T42 Transmission Control Module do?
The TCM acts as the computer for your automatic transmission. It receives data from various sensors on the engine and vehicle, and uses this information to control shift points, line pressure, and torque converter lockup for optimal performance and fuel economy.
Is this module truly plug-and-play?
Yes. We pre-program the module using the VIN you provide during checkout. This ensures it has the correct software and calibration for your specific Saturn Ion, eliminating the need for any additional programming by a dealer.
What happens if I don’t replace a failing TCM?
Continuing to drive with a faulty TCM can lead to more severe issues. Poor shifting can cause excessive wear on internal transmission components like clutches and bands, potentially leading to a complete transmission failure that is far more costly to repair.
How do I know this part will fit my vehicle?
This module is guaranteed to fit 2006-2007 Saturn Ion models. It is also compatible with a wide range of other GM vehicles listed in the description. Matching your original part number to 24243921 or one of the listed interchange numbers will confirm compatibility.
Do I need to send my old part back?
No, there is no core charge for this part. You can keep or dispose of your old module without any hassle or extra fees.