If your 2006-2014 Chevrolet Express 3500 Van is experiencing unpredictable shifting, getting stuck in gear, or has a check engine light pointing to the transmission, you’re likely dealing with a failed Transmission Control Module (TCM). For a workhorse like the Express Van, downtime isn’t an option. This is a direct-fit, OEM-quality T42 TCM, expertly pre-programmed to your van’s specific Vehicle Identification Number (VIN), providing a reliable and straightforward solution to get you back on the road and back to work.
As the command center for your 4L80E or other compatible 4-speed automatic transmission, the TCM dictates every shift, manages torque converter lockup for fuel efficiency, and monitors transmission health. When it fails, the symptoms can range from annoying to debilitating. In my 20+ years in diagnostics, I’ve seen countless work vans sidelined by TCM issues that seem complex but are often solved with this simple component replacement. This module restores the crisp, predictable performance your transmission had from the factory.
From the Diagnostic Bay: The Ghost in the Transmission
A local contractor brought in his ’09 Express 3500, complaining of intermittent, violent 1-2 shifts and occasionally getting stuck in 3rd gear (limp mode), but only after the van was fully warmed up. He’d already replaced a shift solenoid with no luck. We scanned it and found a generic P0700 code. Instead of just throwing more parts at it, we monitored the TCM data stream. We saw erratic commands being sent to the solenoids, a classic sign of internal TCM failure caused by heat soak. We installed one of our VIN-programmed T42 modules. The fix was immediate. The van shifted smoothly, hot or cold. This case highlights why addressing the TCM is often the correct, and most cost-effective, long-term solution.
Is Your Express Van Showing These Telltale Signs?
A failing TCM will give you clear warnings. If you’re experiencing any of the following, it’s time for a replacement:
- â Harsh, delayed, or erratic gear shifts that slam into gear.
- â Vehicle is stuck in a single gear (often called “limp mode”).
- â The Check Engine Light or Transmission Warning Light is on.
- â Diagnostic Trouble Codes (DTCs) are present, such as P0700 (Transmission Control System Malfunction) or other solenoid-specific codes (e.g., P0750, P0753).
- â A noticeable decrease in fuel economy due to inefficient shifting.
- â Complete loss of communication with the transmission module.
Your Straightforward 30-Minute Installation Guide
One of the best features of this module is its simple, plug-and-play installation. No dealership programming is required. For the 2006-2014 Express 3500 TCM, the process is very accessible.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work.
- Locate the Module: On the Express and Savana vans, the TCM is typically found in the engine compartment on the right-hand (passenger) side, mounted to the firewall or inner fender.
- Disconnect and Remove: Carefully unplug the electrical connectors. Use a small screwdriver to gently release the locking tabs if necessary. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, VIN-programmed TCM into place and securely reconnect the electrical harnesses. You will hear a click as they lock in.
- Final Steps: Reconnect the battery terminal. Start the vehicle and let it idle for a moment. While the module is plug-and-play, it’s good practice to use a basic OBD2 scan tool to clear any old fault codes stored in other modules.
Verified Vehicle Compatibility List
This T42 TCM, also known by part numbers 24252114, 24234503, and 24235754, is a direct replacement for a wide range of General Motors vehicles equipped with 4-speed automatic transmissions. While this page focuses on the Express Van, it also fits:
- â Chevrolet: Silverado, Tahoe, Suburban, Avalanche, Cobalt, HHR, Impala, Monte Carlo, Colorado, Express 1500/2500/3500
- â GMC: Sierra, Yukon, Savana 1500/2500/3500, Canyon, Envoy
- â Buick: LaCrosse, Lucerne, Rainier, Allure, Rendezvous
- â Cadillac: DTS
- â Pontiac: G5, G6, Grand Prix, Pursuit
- â Saturn: Vue, Aura, Ion
- â Hummer: H3
- â Saab: 9-7X
Frequently Asked Questions
Frequently Asked Questions
What does VIN programming actually do for my van?
VIN programming loads your van’s specific factory software and calibrations onto the module before it ships. This ensures the TCM communicates perfectly with your engine computer (ECM) and other systems, controlling shift points and pressures exactly as GM intended for your specific vehicle configuration. It makes the installation truly plug-and-play.
Where is the TCM located on a 2006-2014 Express 3500?
On the Chevrolet Express and GMC Savana vans from this era, the Transmission Control Module (TCM) is consistently located in the engine bay, on the right-hand (passenger) side. Look for a silver box with electrical connectors mounted to the body.
Do I need a special scan tool after installation?
No special tools are required for the module to function. It arrives ready to install. However, we recommend using any standard OBD2 scanner to clear any lingering trouble codes from the vehicle’s memory after the battery has been reconnected to ensure a clean slate.
Is this a reliable replacement part?
Absolutely. This module is built to meet or exceed original equipment specifications and is rigorously tested for function and durability. It comes with a one-year warranty, giving you peace of mind that you’re making a lasting repair.
What happens if I don’t replace a failing TCM?
Ignoring a failing TCM can lead to more severe and expensive problems. Continued harsh shifting can cause premature wear on internal transmission components like clutches and bands, and poor performance can leave you stranded. It’s a critical repair for vehicle health and safety.