Tired of Erratic Shifting in Your Chevy Cobalt?
If you’re dealing with the frustrating and unpredictable performance of a failing transmission, you’ve come to the right place. As a technician with over two decades of experience, I’ve seen countless GM vehicles, including the 2006-2010 Chevrolet Cobalt, come into the shop with jerky shifting, delayed gear engagement, or being stuck in limp mode. More often than not, the culprit is a faulty Transmission Control Module (TCM). This VIN-programmed T42 TCM, part number 24255280, is the definitive solution to restore your vehicle’s drivability and peace of mind.
This isn’t just a replacement part; it’s a complete, ready-to-install fix. We handle the programming for you, flashing the module with your vehicle’s specific VIN and the latest GM software updates. This eliminates the need for expensive dealership visits and specialized tools, making it a perfect project for a DIY enthusiast or a time-saving solution for a professional mechanic. By precisely managing shift points, torque converter clutch operation, and line pressure, this module brings back the smooth, responsive feel your Cobalt had when it was new.
A Technician’s Notebook: The Intermittent Cobalt
I remember a 2008 Cobalt that came in with a complaint that stumped the owner. The car would drive perfectly for days, then suddenly start banging into gear and throw a Check Engine light. The codes were generic—P0700 (Transmission Control System Malfunction) and an intermittent solenoid code. After checking the wiring and fluid, everything seemed fine. The issue was heat soak. The original TCM, located on the LH strut tower, was failing internally only after reaching operating temperature. We swapped in a pre-programmed T42 module, and the problem was solved instantly. This is a classic failure mode for these units, and a new, reliable module is the only surefire fix.
Is Your Cobalt Exhibiting 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:
- ✔ Harsh, slamming shifts or erratic gear changes.
- ✔ The vehicle is stuck in one gear (often 2nd or 3rd), also known as “limp mode.”
- ✔ Check Engine Light or Transmission Warning Light is illuminated with Diagnostic Trouble Codes (DTCs) like P0700, P0750, P0753, P0758, or other solenoid-related faults.
- ✔ Failure to upshift or downshift, causing poor acceleration and high RPMs.
- ✔ A noticeable drop in fuel economy.
- ✔ Complete loss of communication with the TCM, preventing diagnostics.
A Straightforward Guide to Installation
Replacing the TCM on your Cobalt is a simple job that can be done in your driveway in under 30 minutes. Here’s how:
- 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 electronic systems.
- Locate the Module: On the 2006-2010 Chevrolet Cobalt, the TCM is conveniently located on the driver’s side (LH) strut tower in the engine bay. It’s a silver box with electrical connectors.
- Disconnect and Remove: Carefully unplug the electrical harnesses from the old TCM. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt your new, pre-programmed TCM into place. Securely plug in the electrical connectors, ensuring they click into place.
- Reconnect and Finalize: Reconnect the negative battery terminal. Start the vehicle. While our programming resolves most codes, it’s good practice to use a basic OBD2 scan tool to clear any stored DTCs from the system.
Verified Vehicle Compatibility
This T42 TCM is a direct replacement for part number 24255280 and is compatible with a wide range of General Motors vehicles. While this page is focused on the Cobalt, it also fits many others. Here is a partial list of confirmed models:
- ✔ 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)
- ✔ Chevrolet Malibu (2006-2010) – Transmission; (LH frame rail)
- ✔ Pontiac G6 (2006-2010) – Transmission; (LH strut tower)
- ✔ Pontiac G5 (2007-2010) – Transmission; (LH strut tower)
- ✔ Saturn Aura (2007-2009) – Transmission; (LH frame rail front)
- ✔ Saturn Ion (2006-2007) – Transmission; (behind LH strut tower)
- ✔ And many more GM cars, trucks, and SUVs from 2006-2014.
Frequently Asked Questions
Does this module really come programmed?
Yes, absolutely. When you place your order, we require your vehicle’s 17-digit VIN. We then flash the module with the correct GM-certified software for your specific vehicle. It arrives at your door ready for plug-and-play installation.
Do I need to send my old part back?
No. We do not require a core return for this part. You can keep your old module or dispose of it, saving you the hassle and cost of a core charge and return shipping.
What tools do I need for the installation?
For most applications, including the Cobalt, you will only need basic hand tools, such as a socket set and a wrench to disconnect the battery terminal. No specialized diagnostic equipment is required for the installation itself.
Will this fix a P0700 trouble code?
A P0700 code is a generic fault code indicating that the TCM has detected a problem and has requested the Check Engine Light to be turned on. While a faulty TCM is a very common cause, this code can also be triggered by other transmission issues. Replacing a known-bad TCM is the most frequent solution for this code.
What is the warranty on this part?
This transmission control module comes with a one-year warranty, giving you confidence in the quality and durability of your repair.