Restore Peak Performance to Your Workhorse Van
If you rely on your 2006-2014 Chevrolet Express 3500 Van for your livelihood, you know that transmission trouble means costly downtime. As a technician with over two decades of experience, I’ve seen firsthand how a failing Transmission Control Module (TCM) can bring a perfectly good work van to a grinding halt. Symptoms like harsh, unpredictable shifting, getting stuck in gear, or a lit check engine light are not just annoyances—they’re a direct threat to your productivity. This T42 TCM, part number 24243921, is the definitive solution to get your van’s transmission operating smoothly and reliably again.
The core of the problem with these modules is often internal circuit failure from years of heat cycles and vibration. This leads to faulty commands being sent to the transmission’s solenoids, causing the frustrating drivability issues you’re experiencing. Our solution is a dependable, OEM-quality 2006-2014 Express 3500 Van TCM that arrives at your door pre-programmed to your specific Vehicle Identification Number (VIN). This eliminates the need for expensive dealership programming, saving you both time and money.
A Technician’s Notebook
I remember a call from a local plumbing company. They had a fleet of Express 3500s, and two of them were acting up with identical, intermittent problems. One day they’d shift perfectly, the next they’d slam into gear or refuse to upshift past 2nd. Their mechanic had already replaced a shift solenoid on one with no change. After they brought one to my shop, a quick scan showed a P0700 (Transmission Control System Malfunction) and some intermittent solenoid circuit codes. Knowing the history of the T42 module, we skipped the wild goose chase. We installed a VIN-programmed TCM, and the problem was solved instantly. They ordered a second one for the other van the same day. It’s a classic failure, and this part is the direct fix.
Is Your Express Van Showing These Telltale Signs?
A faulty TCM can manifest in several ways. If you’re noticing any of the following, it’s a strong indicator that your module needs replacement:
- ✔ Harsh, banging shifts or delayed gear engagement.
- ✔ Vehicle is stuck in “limp mode” (usually 2nd or 3rd gear) and won’t shift.
- ✔ The check engine light or transmission warning light is on.
- ✔ Diagnostic Trouble Codes (DTCs) are present, such as P0700, P0750, P0753, P0758, or other solenoid-related faults.
- ✔ A noticeable decrease in fuel economy.
- ✔ The transmission feels like it’s slipping between gears.
- ✔ Complete loss of communication with the TCM (no response from a scan tool).
Your 30-Minute Path to a Smooth-Shifting Van
This is a job most DIYers or any professional mechanic can complete quickly. For the Express 3500 Van, the TCM is conveniently located, making for a straightforward swap.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and help reset the system.
- Locate the Module: On your Express Van, 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. Then, unbolt the module from its mounting bracket.
- Install the New TCM: Mount the new, pre-programmed module in place and tighten the bolts. Reconnect the electrical connectors, ensuring they click securely into place.
- Final Steps: Reconnect the battery terminal. While our programming handles the critical setup, it’s always good practice to use a basic scan tool to clear any stored DTCs from the engine computer (ECM). Start the vehicle and enjoy restored shifting performance.
Verified Fitment for Your General Motors Vehicle
This T42 TCM is a direct replacement for part number 24243921 and is interchangeable with service numbers like 24242391, 24234503, and 24252114. It fits a wide range of GM vehicles equipped with 4-speed automatic transmissions. While this page focuses on the 2006-2014 Express 3500 Van TCM, it is also compatible with the following models:
EXPRESS 3500 VAN 06-14 Transmission; (RH engine compartment)
SAVANA 2500 VAN 06-14 Transmission; (RH engine compartment)
EXPRESS 2500 VAN 06-14 Transmission; (RH engine compartment)
SAVANA 1500 VAN 06-14 Transmission; (RH engine compartment)
EXPRESS 1500 VAN 06-14 Transmission; (RH engine compartment)
SIERRA 1500 PICKUP 07 Transmission; (new style, smooth door skin), (next to battery)
SILVERADO 1500 PICKUP 07 Transmission; (new style, smooth door skin), (next to battery)
TAHOE 07-09 Transmission; (next to battery)
YUKON 07-09 Transmission; (next to battery)
AVALANCHE 1500 07-08 Transmission; (next to battery)
SUBURBAN 1500 07-08 Transmission; (next to battery)
YUKON XL 1500 07-08 Transmission; (next to battery)
COLORADO 08-12 Transmission; (RH rear engine compartment)
CANYON 08-12 Transmission; (RH rear engine compartment)
HUMMER H3 08-10 Transmission; (RH rear engine compartment)
ENVOY 06-09 Transmission; (LH engine compartment)
TRAILBLAZER 06-09 Transmission; (LH engine compartment)
SAAB 9-7X 06-09 Transmission; (LH engine compartment)
IMPALA 06-11 Transmission; (lower air cleaner housing)
MONTE CARLO 06-07 Transmission; (lower air cleaner housing)
GRAND PRIX 06-08 Transmission; (lower air cleaner housing)
LACROSSE 06-09 Transmission; (lower air cleaner housing)
ALLURE 06-09 Transmission; (lower air cleaner housing)
LUCERNE 06-11 Transmission; (LH engine compartment)
DTS 06-11 Transmission; (RH front engine compartment)
COBALT 06-10 Transmission; (LH strut tower)
G5 07-10 Transmission; (LH strut tower)
HHR 06-11 Transmission; (LH engine compartment)
MALIBU 06-10 Transmission; (LH frame rail)
G6 06-10 Transmission; (LH strut tower)
AURA 07-09 Transmission; (LH frame rail front)
VUE 07-10 Transmission
ION 06-07 Transmission; (behind LH strut tower)
…and many more. Please verify your part number.
Frequently Asked Questions
Frequently Asked Questions
Do I need to get this TCM programmed by a dealer after installation?
No. This module comes fully pre-programmed to your vehicle’s VIN. It is a true plug-and-play solution, saving you the time and expense of a dealership visit.
What’s the difference between a TCM and an ECM?
The ECM (Engine Control Module) is the main computer for the engine’s functions, like fuel and ignition. The TCM (Transmission Control Module) is a dedicated computer that controls only the automatic transmission’s functions, like when to shift gears.
Is this part difficult to install on my Express 3500?
No, it’s considered a very straightforward repair. The TCM is located in an accessible spot in the engine bay, and the replacement requires only basic hand tools and can typically be done in under 30 minutes.
What happens if I install this and my van still has shifting problems?
While this TCM resolves the most common cause of these symptoms, transmission issues can also stem from mechanical problems (like worn clutches) or faulty wiring. Our VIN-programmed module eliminates the computer as the variable, allowing you or your mechanic to confidently diagnose other potential issues if problems persist.
Is there a core charge for my old part?
No, there is no core charge. You can keep or dispose of your old module without the hassle of returning it.