Restore Peak Performance to Your 2006-2014 Chevrolet Express 1500 Van
As an Express Van owner, you rely on your vehicle day in and day out. Whether it’s for hauling cargo, transporting passengers, or serving as a mobile workshop, you can’t afford unexpected downtime. When your transmission starts acting up—with harsh, unpredictable shifts or getting stuck in gear—it’s not just an annoyance; it’s a threat to your schedule and your livelihood. The culprit is often a failing Transmission Control Module (TCM), the electronic brain that orchestrates every gear change. This T42 TCM, a direct replacement for part number 24255280, is the definitive solution to get your workhorse running smoothly again.
Is Your Express Van Showing These Red Flags?
A faulty TCM can manifest in several ways, often starting as a minor intermittent issue before becoming a major problem. From my 20+ years in the bay, these are the classic signs I see time and again with a failing GM T42 module:
- ✔ The transmission slams into gear, especially from Park to Drive or during acceleration.
- ✔ Your van feels sluggish and won’t shift out of 2nd or 3rd gear (commonly known as “limp mode”).
- ✔ The Check Engine Light or a specific transmission warning light is illuminated on your dash.
- ✔ You’ve pulled Diagnostic Trouble Codes (DTCs) like P0700 (Transmission Control System Malfunction) or various solenoid-related codes (e.g., P0751, P0756).
- ✔ A noticeable drop in fuel economy as the transmission isn’t operating in the optimal gear.
- ✔ Complete loss of communication with the module, preventing the vehicle from starting or shifting at all.
A Technician’s Notebook: The Overlooked Fleet Van Failure
I remember a local contractor brought in his 2011 Express 2500. The complaint was intermittent harsh shifting, but only after the van had been running for a few hours on a hot day. His previous mechanic couldn’t replicate it. In my shop, I’ve diagnosed hundreds of these T42 TCM failures. I knew that in work vans like the Express, the TCM is mounted in the engine compartment where it’s exposed to constant heat and vibration. Over years of service, these factors cause internal solder joints and electronic components to fail, leading to the exact heat-related, intermittent symptoms he described. A new, pre-programmed TCM fixed it permanently. This isn’t just a part failure; it’s a predictable wear item in a hard-working vehicle.
The Power of VIN Programming: Skip the Dealership
The single biggest advantage of this module is that it arrives at your door ready for installation. We handle the complex part for you. During checkout, you provide your vehicle’s VIN, and our technicians program the module with the latest GM-certified software specific to your 2006-2014 Express 1500 Van TCM. This means no expensive trips to the dealership for programming, no special scan tools required for setup, and no compatibility headaches. It’s a true plug-and-play repair that restores the precise shift points and torque converter lockup strategy your van was designed with from the factory.
Your 30-Minute Path to a Smooth-Shifting Van
For the confident DIYer or professional mechanic, this is a straightforward job that requires basic hand tools and can be completed in less than half an hour. Getting your van back to perfect working order is easier than you think.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before beginning any electrical work. This prevents short circuits and helps reset the vehicle’s computer systems.
- Locate the TCM: On the Chevrolet Express and GMC Savana vans, the TCM is conveniently located in the engine compartment on the right-hand (passenger) side. You’ll see it mounted with a few bolts and two large electrical connectors.
- Disconnect and Remove: Carefully release the locking tabs on the two electrical connectors and pull them straight off. Then, remove the mounting bolts holding the old module in place and set it aside. There is no core charge, so you don’t need to worry about returning the old part.
- Install the New Module: Mount your new, VIN-programmed TCM in the same location and secure it with the original bolts. Firmly reconnect the two electrical connectors, ensuring they click into place.
- Final Steps: Reconnect the negative battery terminal. Start the vehicle and let it idle for a moment. While the module is pre-programmed, it’s good practice to use a basic OBD2 scanner to clear any stored DTCs from the previous failure. Take your van for a test drive to confirm the smooth shifting.
Verified Fitment Across the GM Lineup
While this part is a perfect fit for your Express Van, the T42 TCM was a workhorse for General Motors, used across a wide range of cars, trucks, and SUVs. This module is also a direct replacement for the following vehicles:
- Chevrolet: Avalanche, Silverado, Suburban, Tahoe, Cobalt, Colorado, HHR, Impala, Malibu, Monte Carlo
- GMC: Sierra, Yukon, Savana, Canyon, Envoy
- Buick: Allure, LaCrosse, Lucerne, Rainier, Rendezvous
- Pontiac: G5, G6, Grand Prix, Pursuit
- Cadillac: DTS
- Saturn: Aura, Ion, Vue
- Hummer: H3
- Saab: 9-7X
This module interchanges with part numbers: 24242391, 24234503, 24252114, 24230461, 24234274, 24235340, 24235754, 24238856, 24239224, 24239926, 24240400, 24241806, 24243901, 24243921, 24255280, 24256960, and more.
Frequently Asked Questions
Do I really need to provide my VIN?
Yes, absolutely. Providing your VIN is critical. It allows us to load the exact factory software for your van’s specific transmission (4L60E, 4L80E, etc.), engine, and options. This ensures perfect communication and optimal performance right out of the box.
Is this a difficult part to install myself?
For most people with basic mechanical skills, this is a very easy installation. On the Express Van, the module is easily accessible in the engine bay. All you need are simple hand tools to unbolt the old one and put the new one in. The whole process typically takes under 30 minutes.
What happens if I don’t clear the codes after installation?
While the new module will function correctly, the old trouble codes (like P0700) will remain stored in the Engine Control Module (ECM). This will likely keep your check engine light on. Clearing the codes ensures your dashboard is clear and you’ll be alerted immediately if any new, unrelated issues arise in the future.
Is there a core charge for my old TCM?
No, there is no core charge. You can keep your old part or recycle it locally without the hassle of shipping it back to us, saving you time and money.
Will this fix my transmission slipping?
This module will correct slipping issues if the cause is electronic—for example, if the TCM is commanding incorrect line pressure or failing to engage the torque converter clutch. However, it will not fix internal mechanical failures like worn-out clutch packs or a failing torque converter. A proper diagnosis is key.