Fix Your Van’s Shifting Problems for Good
As a mechanic with two decades of experience, I know that when your 2006-2014 GMC Savana 1500 Van is down, your business is down. The last thing you need is a complicated, expensive repair. This T42 Transmission Control Module (TCM), part number 24239926, is the straightforward, reliable solution to get your workhorse back on the road. It’s the brain of your automatic transmission, and when it fails, you get frustrating and potentially dangerous symptoms like harsh bangs into gear, getting stuck in limp mode, or a complete refusal to shift. We solve the biggest headache of this repair by programming the module to your van’s specific VIN before it ships. This means no trip to the dealership for expensive programming—it’s a true plug-and-play fix.
Case Study: The Ghost in the Transmission
A local contractor brought in his 2011 Savana 2500, complaining of intermittent, violent shifts and a persistent Check Engine light. His previous mechanic had replaced two shift solenoids, but the problem always returned. Hooking up my pro-level scanner, I saw a generic P0700 code, but also a history of communication loss faults with the TCM. Instead of throwing more parts at it, we inspected the TCM itself. After 150,000 miles of heat cycles and vibration on the engine compartment firewall, the internal connections were failing. We installed one of our VIN-programmed T42 modules. The shifting smoothed out instantly, the codes were cleared, and they haven’t returned since. It’s a classic failure I’ve seen hundreds of times, and a new module is the only permanent fix.
Is Your Van’s Transmission Acting Up?
A faulty TCM can mimic a major mechanical failure. Before you condemn the whole transmission, check if your van is showing these classic electronic symptoms. Replacing a faulty 2006-2014 Savana 1500 TCM can save you thousands in unnecessary repairs.
- âś” Harsh, erratic, or delayed gear shifts that make driving unpredictable.
- âś” Vehicle stuck in a single gear (often called ‘limp mode’) to protect the transmission.
- âś” Check Engine Light or Transmission Warning Light illuminated with codes like P0700 (Transmission Control System Malfunction), P0750-P0758 (Solenoid Faults), or U-codes for communication loss.
- âś” Failure to upshift or downshift, leading to poor acceleration and terrible fuel economy.
- âś” The torque converter failing to lock up at highway speeds, causing RPMs to stay high.
- âś” A complete loss of communication with the scan tool, or no response from the transmission.
A Straightforward Guide to Installation
You don’t need to be a master technician to replace this module. With basic hand tools, you can get this job done in your own driveway in under 30 minutes. For the GMC Savana and Chevrolet Express vans, the process is especially simple.
- Safety First: Always disconnect the negative terminal on your vehicle’s battery to prevent any electrical shorts and to help reset the vehicle’s adaptive memory.
- Locate the TCM: On your Savana van, the TCM is typically mounted in the engine compartment on the right-hand (passenger) side, often on the firewall or inner fender. It’s a silver box with electrical connectors.
- Disconnect and Remove: Carefully unclip the wiring harness connectors. Press the release tabs firmly. Then, unbolt the module from its mounting bracket. There are usually two or three 10mm bolts holding it in place.
- Install the New Module: Bolt the new, VIN-programmed TCM into the original location. Reconnect the wiring harnesses, ensuring they click securely into place.
- Final Steps: Reconnect the battery terminal. Start the vehicle and allow it to idle for a few minutes. If you have a basic scan tool, it’s good practice to clear any lingering fault codes from the system. Take it for a test drive to confirm smooth shifting.
Verified Fitment Across the GM Lineup
While this is the perfect solution for your 2006-2014 Savana 1500 TCM replacement, this versatile T42 module is also a direct-fit, programmed solution for a wide range of other GM cars, trucks, and SUVs equipped with 4-speed automatic transmissions like the 4L60E, 4L65E, and 4L70E. It is a direct replacement for part numbers including 24239926, 24252114, 24234503, 24242391, and more.
Frequently Asked Questions
Do I need to take this part to a dealer for programming?
Absolutely not. We handle all the programming here before we ship it. Just provide your vehicle’s VIN during checkout, and the module will arrive ready for plug-and-play installation, saving you hundreds in dealership fees.
Is this a difficult part to install myself?
Not at all. For most vehicles, including the Savana van, it’s located in the engine bay and held on by a few bolts. With basic tools, it’s a 30-minute job for most DIYers. Our installation guide above walks you through the simple steps.
What is a ‘core charge’ and do you require one?
A core charge is a deposit you pay until you return your old part. We do not have a core charge on this module. You can keep your old part or recycle it without any hassle or extra cost.
Will this fix my P0700 Check Engine light code?
In many cases, yes. A P0700 code is a general fault code indicating the TCM has detected a problem. If the TCM itself is the source of the fault (which is very common), replacing it with our programmed unit will resolve the code and the underlying shifting issues.
What kind of warranty comes with this module?
This module is backed by our solid one-year, hassle-free warranty. We stand by the quality of our parts and programming, giving you confidence in your repair.