Restore Your Van’s Shifting with a Programmed T42 TCM
If your 2006-2014 GMC Savana 2500 is your workhorse, you can’t afford downtime caused by a failing transmission. As a technician with over two decades of experience, I’ve seen countless work vans sidelined by transmission problems that seem complex but often trace back to one component: the Transmission Control Module (TCM). When your van starts shifting harshly, gets stuck in gear, or throws a check engine light, this T42 TCM, part number 24235340, is the reliable, straightforward fix you need to get back on the road and back to business.
The TCM is the brain of your automatic transmission, constantly managing hydraulic pressure, shift points, and torque converter lockup. Over time, the constant heat and vibration in the engine bay take their toll, leading to internal circuit failure. This isn’t just an inconvenience; it can cause poor fuel economy, damage to internal transmission components, and leave you stranded. This replacement Savana 2500 Transmission Module is engineered to meet or exceed original equipment specifications, ensuring a dependable, long-term solution.
Case Study: A Tricky Diagnosis
A local contractor brought in his ’09 Savana 2500, complaining of intermittent, violent downshifts and occasional limp mode, but no consistent check engine light. He’d already replaced a shift solenoid with no luck. After connecting my scan tool, I noticed erratic data from the transmission output speed sensor, but the sensor itself tested fine. Experience pointed me to the TCM. After swapping in a pre-programmed module, the data stream stabilized instantly. The van shifted perfectly on the test drive. It wasn’t the transmission itself, but the computer controlling it—a common scenario I’ve diagnosed on hundreds of GM trucks and vans.
Is Your Van Showing These Telltale Signs?
A faulty TCM can manifest in several ways. If you’re experiencing any of the following, it’s a strong indicator that your module needs replacement:
- ✔ Harsh, slamming shifts or delayed gear engagement.
- ✔ The vehicle is stuck in “limp mode” (usually 2nd or 3rd gear).
- ✔ Check Engine Light or Transmission Warning Light is on with codes like P0700 (Transmission Control System Malfunction), P0750, or other solenoid-related DTCs.
- ✔ Failure to upshift or downshift, leading to high RPMs or bogging down.
- ✔ A noticeable drop in fuel efficiency.
- ✔ Complete loss of communication with the TCM (a U-code).
A Straightforward Guide to Installation
One of the best features of this module is that it arrives pre-programmed to your vehicle’s VIN. This eliminates the need for expensive dealership programming. The physical installation is simple and can be done in your driveway in under 30 minutes with basic hand tools. For your specific Savana 2500 Transmission Module, you’ll find it in the engine compartment on the right-hand side.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent electrical shorts and help reset the system.
- Locate the Old Module: On the Savana 2500, the TCM is mounted in the right-hand side of the engine compartment. Identify the module and its electrical connectors.
- Disconnect and Remove: Carefully unplug the wiring harnesses. They have locking tabs that may need to be gently pried. Once disconnected, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCM into place. Securely reconnect the wiring harnesses, ensuring they click into place.
- Final Steps: Reconnect the negative battery terminal. While the system often resets, it’s best practice to use a basic OBD2 scan tool to clear any stored fault codes. Start the vehicle and take it for a test drive to confirm smooth shifting.
Verified Vehicle Compatibility
This T42 TCM is a direct replacement for a wide range of General Motors vehicles. Please verify your model and year below. This part is interchangeable with service numbers 24242391, 24234503, 24252114, and many others.
- GMC SAVANA 2500 VAN (2006-2014) – Location: RH engine compartment
- Chevrolet Silverado & GMC Sierra (2007-2013) – Location: Next to battery
- Chevrolet Tahoe & GMC Yukon (2007-2009) – Location: Next to battery
- Chevrolet Express Van (1500/2500/3500) (2006-2014) – Location: RH engine compartment
- Cadillac DTS (2006-2011) – Location: RH front engine compartment
- Buick LaCrosse / Allure (2006-2009) – Location: Lower air cleaner housing
- Pontiac G6 (2006-2010) – Location: LH strut tower
- Hummer H3 (2008-2010) – Location: RH rear engine compartment
- …and many more models listed in the fitment data.
Do I need to take this module to a dealer for programming?
Do I need to take this module to a dealer for programming?
No. We program the module to your vehicle’s specific VIN before shipping. This makes it a true plug-and-play solution, saving you a trip to the dealership and the associated programming fees.
Will this fix a P0700 diagnostic trouble code?
A P0700 code is a general fault code indicating the TCM has detected a problem. While a faulty TCM is a very common cause, this code can also be triggered by other issues like bad solenoids or wiring. However, if you’re experiencing other symptoms like erratic shifting, replacing the TCM is often the correct fix.
Where is the TCM located on my 2011 Savana 2500?
For the 2006-2014 GMC Savana 2500 and Express vans, the Transmission Control Module is located in the engine bay, on the right-hand (passenger) side.
Is there a core charge for this part?
No, there is no core charge. You are not required to send your old, faulty module back to us, which simplifies the process for you.