Is Your Saturn Ion Driving You Crazy with Shifting Problems?
If you’re dealing with a 2006-2007 Saturn Ion that jerks, hesitates, or refuses to shift properly, you’re not alone. I’ve seen this countless times in my 20+ years as a technician. The culprit is often a failed Transmission Control Module (TCM), the electronic brain of your automatic transmission. When it goes bad, it can make your daily drive a frustrating and unpredictable experience. This T42 TCM, part number 24240449, is the definitive solution, arriving pre-programmed to your vehicle’s specific VIN for a true plug-and-play fix.
Forget about expensive dealership visits and the hassle of post-installation programming. We handle all the software flashing for you. This module directly communicates with your vehicle’s engine computer and sensors to manage shift points, torque converter clutch engagement, and line pressure, restoring the smooth, reliable performance you expect from your car. By installing this OEM-quality module, you’re not just fixing a symptom; you’re addressing the root cause of common transmission issues and preventing potential long-term damage to expensive mechanical components.
Case Study: A Tricky Diagnosis
A customer brought in a 2007 Saturn Ion with classic signs of transmission failure: it was stuck in 3rd gear (limp mode) and had a check engine light with a P0700 code. They were convinced they needed a full transmission rebuild, a multi-thousand-dollar job. After a quick scan, I saw several solenoid circuit codes pointing towards an electrical fault. Instead of tearing down the transmission, I checked the TCM. Sure enough, after swapping in a pre-programmed T42 module, all the codes cleared and the car shifted perfectly. We saved the customer over two thousand dollars and a week of downtime. It’s a powerful reminder that sometimes the simplest fix is the right one.
Common Signs of a Failing T42 TCM
- âś” Harsh, erratic, or delayed gear shifts that make driving uncomfortable.
- âś” Vehicle is stuck in “limp mode,” usually in 2nd or 3rd gear, with limited speed.
- âś” The Check Engine Light or Transmission Warning Light is illuminated on your dash.
- âś” Diagnostic Trouble Codes (DTCs) are present, such as P0700, P0750, P0753, P0758, or other solenoid-related faults.
- âś” Complete loss of shifting capability or intermittent failure to engage gears.
- âś” A noticeable drop in fuel economy as the transmission operates inefficiently.
Your 30-Minute Path to Smooth Shifting
Installing your new 2006-2007 Ion TCM is a straightforward job that most DIYers can complete in their driveway. For the Saturn Ion, the module is conveniently located and easily accessible.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work. This prevents short circuits and helps reset the vehicle’s internal systems.
- Locate the Old TCM: On your 2006-2007 Saturn Ion, you’ll find the Transmission Control Module 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 breaking them. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt your 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 battery terminal. Start the vehicle and let it idle for a few minutes. While the module is plug-and-play, it’s good practice to use a basic OBD2 scanner to clear any stored fault codes from the previous failure. Take a test drive to confirm smooth shifting.
Verified Vehicle Compatibility
This T42 TCM is a direct replacement for part number 24240449 and is interchangeable with a wide range of other service numbers. While this page focuses on the 2006-2007 Ion TCM, it is also compatible with many other GM vehicles. Please verify your part number or consult the list below. The location of the TCM is noted for your convenience.
- Saturn Ion (2006-2007): Transmission; (behind LH strut tower)
- Chevrolet Cobalt (2006-2010): Transmission; (LH strut tower)
- Chevrolet HHR (2006-2011): Transmission; (LH engine compartment)
- Chevrolet Impala (2006-2011): Transmission; (lower air cleaner housing)
- GMC Sierra & Chevrolet Silverado (2007-2013): Transmission; (next to battery)
- Pontiac G6 (2006-2010): Transmission; (LH strut tower)
- …and many other GM models listed in the original fitment data.
Do I need to program this TCM at the dealership?
Do I need to program this TCM at the dealership?
No, you do not. This module comes fully pre-programmed to your vehicle’s VIN. It is ready for installation right out of the box, saving you hundreds of dollars in dealership programming fees.
What is a T42 TCM?
The T42 is a specific generation of Transmission Control Module used by General Motors in a wide range of vehicles, primarily with 4-speed automatic transmissions like the 4L60E and 4L65E. It is responsible for all electronic control of the transmission.
Will this fix a P0700 trouble code?
A P0700 code is a general fault request from the TCM to the Engine Control Module (ECM) to turn on the check engine light. While a faulty TCM is a very common cause, you should scan for more specific transmission codes (e.g., P07xx) to confirm the diagnosis. In many cases, replacing a failed TCM will resolve the P0700 and related codes.
Is there a core charge for my old part?
No, there is no core charge required for this part. You can keep your old module or dispose of it without the hassle of returning it.