Are you experiencing frustrating and unpredictable shifting in your 2006-2007 Saturn Ion? A faulty Transmission Control Module (TCM) is often the culprit behind issues like harsh gear changes, getting stuck in gear, or the dreaded check engine light. This genuine GM T42 Transmission Control Module, part number 24241806, is the definitive solution to restore your vehicle’s transmission performance. It arrives pre-programmed to your vehicle’s specific VIN, eliminating the need for expensive dealership visits and ensuring a seamless, plug-and-play installation.
From the Diagnostic Bay
We had a 2007 Chevrolet Cobalt come in that the owner had already replaced two shift solenoids on, trying to chase down an intermittent P0752 (Shift Solenoid ‘A’ Stuck On) code. The shifts were incredibly harsh, especially from 1st to 2nd. After confirming the solenoids and wiring were good, we suspected the TCM. The internal drivers that control the solenoids can weaken over time, causing erratic behavior that mimics a bad solenoid. We installed a VIN-programmed T42 module, cleared the codes, and the car shifted like it just rolled off the factory floor. The customer was thrilled to finally have a reliable fix instead of just replacing parts.
Diagnosing Your 2006-2007 Saturn Ion TCM
The TCM is the brain of your automatic transmission. It processes data from various sensors to control shift solenoids, regulate hydraulic pressure, and manage torque converter lockup. When it fails, the communication breaks down, leading to a cascade of performance problems. Replacing a failing module is critical to prevent further damage to your transmission’s mechanical components. This module is a direct-fit replacement, engineered to meet or exceed original equipment specifications for reliability and longevity.
Common Symptoms of a Failing T42 TCM
- ✔ Harsh, erratic, or delayed gear shifting.
- ✔ Vehicle enters ‘limp mode,’ often stuck in 2nd or 3rd gear.
- ✔ Check Engine Light or Transmission Warning Light is illuminated.
- ✔ Diagnostic Trouble Codes (DTCs) such as P0700, P0750, P0751, P0756, or other solenoid-related codes are present.
- ✔ Inability to upshift or downshift properly.
- ✔ A noticeable decrease in fuel economy.
- ✔ Complete loss of transmission function in severe cases.
Key Features of This Programmed T42 Module
- ✔ VIN-Programmed for Your Vehicle: We program the module with the latest GM software updates using your car’s VIN. This ensures perfect communication with the Engine Control Module (ECM) and other vehicle systems right out of the box.
- ✔ Plug-and-Play Installation: No additional programming or dealer intervention is required. Simply install the module, connect the harnesses, and you’re ready to drive.
- ✔ Restores Original Performance: Cures common shifting problems, eliminates fault codes, and restores the smooth, efficient operation of your transmission.
- ✔ Broad GM Compatibility: While perfect for the Saturn Ion, this T42 TCM is also compatible with a wide range of GM vehicles, including the Chevrolet Cobalt, HHR, Malibu, Impala; Pontiac G6; and Saturn Vue.
- ✔ No Core Charge: Keep your old part without the hassle or expense of a core return, saving you time and money.
Installation Guide
For the 2006-2007 Saturn Ion, the TCM is typically located behind the driver-side strut tower in the engine compartment. The installation process is straightforward for a DIY mechanic with basic tools. Always disconnect the negative battery terminal before beginning. Carefully unplug the electrical connectors, unbolt the old module, and install the new one in its place. Reconnect the harnesses and the battery. While the module is plug-and-play, it’s always a good practice to use a scan tool to clear any stored fault codes after installation.
Frequently Asked Questions
What does a T42 Transmission Control Module do?
The T42 TCM is an electronic computer that acts as the ‘brain’ for your automatic transmission. It receives data from sensors on the engine and transmission to control shift timing, line pressure, and torque converter clutch operation for optimal performance and fuel efficiency.
Why is VIN programming so important for this part?
VIN programming loads your vehicle’s specific calibration files onto the module. This ensures it communicates correctly with your car’s engine computer and other systems. Without it, you could experience incorrect shifting, fault codes, or even a no-start condition.
Will this module fix a P0700 trouble code?
A P0700 code is a general fault code indicating the TCM has detected a problem and has requested the Check Engine Light to be turned on. While a faulty TCM can cause a P0700, it’s important to scan for more specific transmission codes (like P07xx) to pinpoint the exact issue. This module often resolves the underlying cause of the P0700 code.
Is this a difficult part to install myself?
For most individuals with basic mechanical skills, this is a manageable job. The module is typically easy to access in the engine bay. The most important steps are disconnecting the battery first and ensuring the electrical connectors are securely seated on the new module. The entire process often takes less than an hour.
Does this part have a warranty?
Yes, this transmission control module comes with a one-year warranty, giving you peace of mind with your purchase.