If your 2006-2014 GMC Savana 3500 work van is experiencing shifting problems, you know that downtime isn’t just an inconvenience—it’s costing you money. Before you consider a costly and time-consuming transmission replacement, the problem is very often the Transmission Control Module (TCM). As the electronic brain of your automatic transmission, the T42 TCM manages everything from shift points to torque converter clutch engagement. When it fails, it can mimic a major mechanical failure, causing erratic shifting, getting stuck in gear, or triggering warning lights on your dash.
This replacement T42 Transmission Control Module, part number 24243921, is the definitive solution for restoring your van’s performance and reliability. The most significant benefit is that we program it to your vehicle’s specific VIN before it ships. This means no expensive trips to the dealership for programming. It arrives at your door ready for a true plug-and-play installation, getting your workhorse back on the road fast.
From the Diagnostic Bay: The Case of the Slipping Fleet Van
A local contractor brought in his 2011 Savana 3500, convinced the transmission was shot. It was slamming into gear and would randomly go into limp mode, stuck in 3rd. His other mechanic quoted him over $3,500 for a transmission rebuild. I hooked up my scan tool and saw a classic P0700 (Transmission Control System Malfunction) and several solenoid circuit codes. In my experience, seeing multiple, intermittent solenoid codes often points to the controller, not the individual solenoids. We swapped in a VIN-programmed 2006-2014 Savana 3500 TCM. The total repair time was under an hour, and the van shifted perfectly. He was back on the job the same day, saving thousands of dollars and avoiding weeks of downtime.
Is Your Savana Van Showing These Warning Signs?
- ✔️ Harsh, banging shifts or delayed gear engagement.
- ✔️ The vehicle is stuck in “limp mode” and won’t shift out of 2nd or 3rd gear.
- ✔️ Check Engine Light or Transmission Warning Light is illuminated.
- ✔️ Diagnostic Trouble Codes (DTCs) are present, such as P0700, P0750, P0753, P0758, or other solenoid-related faults.
- ✔️ Complete loss of shifting capability or intermittent communication failure with the module.
- ✔️ Poor fuel economy and a feeling of sluggish performance.
A Straightforward Guide to a 30-Minute Fix
Installation is simple enough for a seasoned DIYer or any professional technician. For the Savana Van, the TCM is typically easy to access.
- Safety First: Always disconnect the negative terminal on your vehicle’s battery before starting any electrical work.
- Locate the Module: On the Savana 1500, 2500, and 3500 vans, you’ll find the TCM in the engine compartment on the right-hand (passenger) side.
- Disconnect and Remove: Carefully unplug the electrical connectors. Be gentle with the locking tabs. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCM into place and securely reconnect the electrical harnesses.
- Reconnect and Verify: Reconnect the battery terminal. Start the vehicle and ensure all warning lights are off. A short test drive will confirm that normal shifting has been restored.
Verified Compatibility for Your GM Vehicle
While this is a direct-fit solution for the 2006-2014 Savana 3500 TCM, this versatile T42 module is also compatible with a wide range of other GM cars, trucks, and SUVs equipped with 4-speed automatic transmissions like the 4L60E, 4L65E, and 4L80E. It is a direct interchange for part numbers 24252114, 24234503, 24230461, 24234274, 24243921, and more. Please verify your specific model in the fitment list below.
Frequently Asked Questions
What does ‘VIN Programmed’ actually mean for me?
It means the module arrives ready to install right out of the box. We load your vehicle’s specific Vehicle Identification Number (VIN) and the latest GM software onto the module before shipping. This ensures it communicates perfectly with your van’s engine computer and other systems, eliminating the need for a dealership visit and extra programming fees.
Do I need any special tools for this installation?
No special tools are required. Basic hand tools, such as a socket set to remove the mounting bolts and potentially a small flathead screwdriver to help release the connector tabs, are all you should need. The entire process typically takes less than 30 minutes.
Will this 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 this module often resolves the root cause (like internal shorts or failed drivers that trigger other codes), you should always diagnose any other specific transmission codes (e.g., for solenoids or sensors) that accompany the P0700 to confirm the TCM is the point of failure.
Is there a core charge for my old part?
No, there is absolutely no core charge. You can keep your old part or dispose of it at your convenience, making the transaction simple and hassle-free.