Restore Peak Transmission Performance to Your GM Vehicle
As a technician with over two decades of experience, I’ve seen firsthand how a failing Transmission Control Module (TCM) can bring a dependable workhorse like a GMC Savana van to a grinding halt. If you’re dealing with erratic shifting, a check engine light that won’t quit, or your vehicle being stuck in limp mode, the problem often points directly to this critical component. This T42 Transmission Control Module, corresponding to part number 24255280, is the definitive solution for restoring the crisp, reliable shifting your vehicle had when it was new.
The TCM is the brain of your automatic transmission, responsible for processing sensor data to control shift points, torque converter lockup, and line pressure. When it fails, communication breaks down, leading to the frustrating and sometimes dangerous symptoms you’re experiencing. What makes this particular module the smart choice for both professional mechanics and DIYers is our pre-programming service. We flash the module with your vehicle’s specific VIN and the latest GM software updates before it ships. This eliminates the need for an expensive trip to the dealership for programming, saving you time, money, and hassle. It arrives ready for a true plug-and-play installation.
Case Study: The Fleet Van That Wouldn’t Shift
A local contractor brought in his 2011 Savana 3500 work van, complaining it was stuck in third gear and the transmission temperature light was on. His business was losing money every hour the van was down. A quick scan showed a P0700 (Transmission Control System Malfunction) and several solenoid circuit codes. After confirming the wiring harness was intact, we identified a faulty TCM. Instead of sending him to the dealer for a new module and programming, we ordered one of these pre-programmed units. It arrived the next day, and the installation took less than 20 minutes. The van was back on the road, shifting perfectly, before lunch. This is the kind of efficient, reliable repair that keeps businesses running.
Is Your Savana Van Showing These Telltale Signs?
A failing TCM doesn’t heal itself; it only gets worse. If you notice any of the following issues, it’s time to diagnose the module. This is especially true if you have a 2006-2014 Savana 3500 TCM that’s never been replaced.
- âś” Harsh, banging shifts or delayed gear engagement.
- âś” Vehicle is stuck in one gear (often called “limp mode”).
- âś” The check engine light or transmission warning light is illuminated.
- âś” Diagnostic Trouble Codes (DTCs) are present, such as P0700, P0750, P0753, P0758, or other solenoid-related faults.
- âś” Inability to upshift or downshift, leading to poor acceleration and terrible fuel economy.
- âś” Intermittent loss of communication with the scanner or other modules.
A Straightforward Guide to Installation
One of the best features of this module is its simple installation. For most Savana and Express vans, you can have this job done in under 30 minutes with basic hand tools.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent electrical shorts and help reset the system.
- Locate the TCM: On the 2006-2014 Savana 3500, the TCM is typically found in the engine compartment on the right-hand (passenger) side.
- Disconnect and Remove: Carefully unplug the electrical connectors. Press the release tabs firmly to avoid damaging them. Then, unbolt the old module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCM into place. Reconnect the electrical connectors, ensuring they click securely into position.
- Final Steps: Reconnect the battery terminal. While the module is plug-and-play, it’s always best practice to use a scan tool to clear any stored DTCs from the system’s memory. Start the vehicle and test drive to confirm smooth shifting.
Verified Vehicle Compatibility
This T42 TCM is a direct replacement for a wide range of General Motors vehicles. It is interchangeable with numerous part numbers, including 24252114, 24234503, 24230461, 24234274, 24255280, and more. While this is the correct 2006-2014 Savana 3500 TCM, it also fits many other models. Please verify your specific application from the list below:
- Chevrolet: Avalanche, Cobalt, Colorado, Express 1500/2500/3500, HHR, Impala, Malibu, Monte Carlo, Silverado 1500/2500, SSR, Tahoe, Suburban 1500
- GMC: Canyon, Envoy, Envoy XL, Sierra 1500/2500, Savana 1500/2500/3500, Yukon, Yukon XL 1500
- Buick: Allure, LaCrosse, Lucerne, Rainier, Rendezvous
- Cadillac: DTS
- Pontiac: G5, G6, Grand Prix, Pursuit
- Saturn: Aura, Ion, Vue
- Hummer: H3
- Saab: 9-7X
Frequently Asked Questions
Do I need to have this module programmed by a dealer?
No. We handle all the programming for you. Simply provide your vehicle’s VIN during checkout, and the module will arrive ready to install, with no additional programming required.
What tools do I need for installation?
For most vehicles, you will only need a basic socket set to remove the mounting bolts and a flathead screwdriver to gently pry the connector tabs if they are stuck. Installation is designed to be simple for any skill level.
Is there a core charge for my old part?
No, there is no core charge. You can keep your old module or dispose of it without the hassle of shipping it back to us.
Will this fix a P0700 code?
A P0700 code is a general fault code indicating the TCM has detected a problem. This module often resolves the underlying issue causing the P0700, especially when accompanied by other transmission-specific codes.
What is the warranty on this part?
This Transmission Control Module is backed by a one-year warranty, giving you peace of mind and confidence in your repair.