If your 2006-2014 Chevrolet Express 2500 is your livelihood, you can’t afford downtime caused by a failing transmission. When you experience unpredictable shifting, a check engine light that won’t go away, or your van gets stuck in limp mode, the problem often points directly to the Transmission Control Module (TCM). This critical component is the brain of your automatic transmission, and when it fails, it can bring your work to a grinding halt. This T42 TCM, part number 24234274, is the reliable, dealership-free solution to get your van running smoothly again.
As a technician with over two decades of experience, I’ve seen countless work vans sidelined by faulty electronics. The symptoms can be frustratingly intermittent, but they almost always get worse. This replacement module is built to OEM specifications and comes pre-programmed to your van’s specific Vehicle Identification Number (VIN). This means you can skip the expensive trip to the dealership for programming—it arrives ready for a true plug-and-play installation, restoring precise shifting logic and communication with your engine computer right out of the box.
Case Study: The Ghost in the Transmission
I once had a 2011 Express 2500 in my bay that was giving the owner fits. He’d complain of a hard 1-2 shift, but only after the van was fully warmed up and had been driven for over an hour. We couldn’t replicate it on short test drives. There were no consistent trouble codes, just a generic P0700 (Transmission Control System Malfunction) that would pop up occasionally. After checking the fluid, solenoids, and wiring harness with no luck, we focused on the TCM. Heat soak was causing an internal fault in the module, disrupting the shift commands. Swapping in a VIN-programmed Express 2500 Van TCM solved the problem instantly. The owner was back on the road the same day, no more ghost shifts.
Is Your Express Van Showing These Telltale Signs?
A failing TCM doesn’t heal itself. If you’re noticing any of these issues, it’s time to diagnose the module. Ignoring them can lead to more significant and costly transmission damage.
- ✔ Harsh, slamming shifts or delayed gear engagement.
- ✔ The vehicle is stuck in a single gear (often 2nd or 3rd), known as “limp mode.”
- ✔ An illuminated Check Engine Light or Transmission Warning Light.
- ✔ Diagnostic Trouble Codes (DTCs) stored, such as P0700, P0750, P0755, or other solenoid-related faults.
- ✔ Inability to upshift or downshift correctly, leading to poor acceleration.
- ✔ A noticeable drop in fuel economy or signs of the transmission overheating.
A Straightforward Guide to Installation
You don’t need to be a master mechanic to replace this module. The entire process can typically be done in under 30 minutes with basic hand tools. For the Chevrolet Express and GMC Savana vans, the TCM is conveniently located in the engine compartment.
- Safety First: Before you begin, disconnect the negative terminal from your vehicle’s battery. This prevents any electrical shorts and helps reset the vehicle’s computer systems.
- Locate the Module: On your Express 2500 van, the TCM is found on the right-hand (passenger) side of the engine compartment. It’s a silver box with electrical connectors.
- Disconnect and Remove: Carefully unplug the electrical harness connectors. Then, unbolt the module from its mounting bracket and remove it from the vehicle.
- Install the New Module: Mount the new, pre-programmed TCM in the same location and securely fasten the bolts. Reconnect the electrical harnesses, ensuring they click into place.
- Final Steps: Reconnect the negative battery terminal. While our programming resolves most codes, it’s good practice to use a basic scan tool to clear any lingering DTCs from the system’s memory.
Verified Fitment Across GM Models
While this is the perfect solution for your Express 2500 Van TCM, this versatile T42 module is also a direct replacement for a wide array of other General Motors vehicles equipped with 4-speed automatic transmissions like the 4L60E, 4L65E, and 4L80E. It is interchangeable with part numbers 24252114, 24234503, 24230461, and more.
This part is confirmed to fit:
- Chevrolet Express / GMC Savana 1500, 2500, 3500 (2006-2014)
- Chevrolet Silverado / GMC Sierra (2007-2013)
- Chevrolet Tahoe / GMC Yukon (2007-2009)
- Chevrolet Impala (2006-2011)
- Chevrolet HHR (2006-2011) & Cobalt (2006-2010)
- Cadillac DTS (2006-2011)
- Buick LaCrosse / Lucerne (2006-2011)
- Pontiac G6 / Grand Prix (2006-2010)
- Hummer H3 (2008-2010)
- And many others. Refer to the full fitment list for details.
Frequently Asked Questions
What does ‘VIN Programmed’ actually mean for me?
It means this module arrives at your door ready to install. We load it with the specific software and calibrations for your van using your VIN. This eliminates the need for expensive programming tools or a trip to the dealership, saving you time and money and ensuring perfect compatibility.
Is this part really difficult to install myself?
Not at all. For a DIY enthusiast with basic tools, this is a very manageable job. On the Express Van, the TCM is easily accessible in the engine bay. The entire swap usually 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. While this module often resolves the root cause (like an internal TCM failure that triggers the P0700), you should ensure other issues like bad solenoids or wiring are not present. In many cases, a faulty TCM is the primary culprit.
Do I need to send my old part back? Is there a core charge?
No. We do not require a core return for this part. You can keep your old module or dispose of it, making the process hassle-free.
What transmissions is this T42 module compatible with?
This T42 TCM is designed for vehicles equipped with GM’s popular 4-speed automatic transmissions, including the 4L60E, 4L65E, 4L70E, and 4L80E.