If your 2006-2007 Saturn Ion is suffering from erratic shifting, getting stuck in gear, or has the check engine light on with transmission codes, you’ve likely pinpointed a failing Transmission Control Module (TCM). As a technician with over two decades of experience, I’ve seen countless GM vehicles, from compacts like the Ion and Cobalt to workhorse trucks, sidelined by this exact issue. The TCM is the brain of your automatic transmission, and when it fails, it creates frustrating and unpredictable driving behavior. This isn’t just an annoyance; it’s a reliability issue that needs a solid fix.
This T42 TCM is the definitive solution. It arrives at your door fully pre-programmed to your vehicle’s specific VIN. This is the most critical feature, as it eliminates the need for expensive and time-consuming programming at a dealership. You get a part that is truly plug-and-play, restoring the precise shift logic and communication that your vehicle had when it was new. It’s designed to directly resolve common Diagnostic Trouble Codes (DTCs) like P0700 (Transmission Control System Malfunction) and various solenoid-related codes that point to an internal TCM fault.
A Technician’s Notebook
I remember a 2007 Saturn Ion that came into the shop a few months back. The owner was frustrated because the car would randomly refuse to shift past 2nd gear, making highway driving impossible. They had already replaced a shift solenoid based on a code, but the problem persisted. After a quick diagnostic, I suspected the T42 module. We ordered one of these pre-programmed units, and the installation took less than 20 minutes. The moment we reconnected the battery and started it up, the car shifted perfectly. The customer saved hundreds compared to the dealership quote and drove away with a car that felt brand new again. It’s a classic case where the root cause is the controller, not the mechanical parts.
Is Your Saturn Showing These Telltale Signs?
A failing TCM will give you clear warnings. If you’re experiencing any of the following, it’s time for a replacement:
- âś” Harsh, banging shifts or delayed gear engagement.
- âś” Vehicle is stuck in “limp mode” (usually second or third gear).
- âś” Check Engine Light is on with codes like P0700, P0750, P0753, P0758.
- âś” The transmission refuses to upshift or downshift correctly.
- âś” A sudden drop in fuel economy.
- âś” No communication with the transmission module when using a scan tool.
Your 30-Minute Path to Smooth Shifting
Installing this 2006-2007 Ion transmission module is a straightforward job perfect for a DIYer. No specialized tools are needed.
- 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 Saturn Ion, the TCM is typically found behind the driver-side strut tower in the engine compartment. It’s a silver box with electrical connectors.
- Disconnect and Remove: Carefully unplug the wiring harness connectors. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCM into place and securely reconnect the wiring harnesses. Ensure they click into place.
- Final Steps: Reconnect the battery terminal. Start the vehicle and let it idle for a few minutes. If you have a basic scan tool, it’s good practice to clear any stored fault codes. Take the vehicle for a test drive to confirm smooth shifting.
Verified Fitment For These GM Vehicles
While this is a perfect fit for the 2006-2007 Ion transmission module, it is also compatible with a wide range of other GM vehicles. This part is interchangeable with service numbers 24242391, 24234503, 24252114, 24238856, and more. Please verify your model below:
- Saturn: Ion (2006-2007), Vue (2007-2010), Aura (2007-2009)
- Chevrolet: Cobalt (2006-2010), HHR (2006-2011), Impala (2006-2011), Monte Carlo (2006-2007), Silverado, Tahoe, Express Van, and more.
- Pontiac: G5 (2007-2010), G6 (2006-2010), Grand Prix (2006-2008)
- GMC: Sierra, Yukon, Savana Van
- Buick: LaCrosse (2006-2009), Lucerne (2006-2011)
- And many other GM models from 2006-2014. Check the detailed list for your specific application.
Do I need to take my car to the dealer after installation?
Do I need to take my car to the dealer after installation?
No. This transmission control module comes fully programmed to your vehicle’s VIN. It is a plug-and-play installation that does not require any additional programming or trips to the dealership, saving you time and money.
What is the warranty on this part?
This module is backed by our one-year, hassle-free warranty. We stand by the quality and reliability of our programmed electronics, giving you peace of mind with your repair.
Is this a guaranteed fix for my shifting problems?
This module corrects failures internal to the TCM, which are the cause of most common GM shifting issues like harsh shifts, limp mode, and communication codes. While other issues can exist (like faulty wiring or solenoids), a bad TCM is the most frequent culprit. This part is the direct solution for a failed module.
Do I need to return my old part?
No, there is no core charge for this part. You can keep or dispose of your old module without any extra hassle or fees.