Is your Chevrolet Express Van suffering from harsh shifting, getting stuck in gear, or throwing transmission codes? A faulty Transmission Control Module (TCM) is one of the most common culprits behind these frustrating and unpredictable issues. This OEM-quality T42 TCM, part number 24235340, is the definitive solution, arriving pre-programmed to your vehicle’s specific VIN. This means no expensive trips to the dealership for programming—it’s a true plug-and-play fix that restores your van’s performance and reliability.
A Technician’s Notebook: The Common T42 Failure
In my 20+ years in the bay, I’ve seen hundreds of these GM vehicles—from workhorse Express vans to family SUVs—come in with erratic transmission behavior. More often than not, the T42 TCM is the root cause. Located in the engine bay, these modules are constantly exposed to intense heat cycles and vibration. Over time, this stress causes internal solder joints and electronic components to fail, leading to the intermittent connection drops and false sensor readings that trigger limp mode (stuck in 2nd or 3rd gear) and a flurry of diagnostic trouble codes. Replacing it with a quality, properly programmed unit isn’t just a repair; it’s a necessary step to prevent being stranded.
Diagnosing Your Transmission Woes: Is Your TCM the Problem?
If your van is exhibiting any of the following symptoms, a failing TCM is highly likely. A quick scan for codes can often confirm the diagnosis, pointing directly to a control module or solenoid circuit fault that originates inside the module itself.
- ✔ Harsh, slamming shifts or delayed gear engagement.
- ✔ Vehicle is stuck in ‘limp mode’ and won’t shift out of a single gear.
- ✔ Check Engine Light is on with codes like P0700, P0750, P0753, P0758, or other transmission solenoid codes.
- ✔ Complete loss of communication with the transmission module (U-codes).
- ✔ A sudden drop in fuel efficiency or a transmission overheating warning.
- ✔ No response from the transmission when shifting from Park to Drive or Reverse.
A Straightforward Guide to Your 2006-2014 Express 2500 TCM Installation
One of the best features of this module is its simple installation. You don’t need specialized tools or a professional lift. For most owners with basic hand tools, this is a job that can be completed in under 30 minutes right in your driveway.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and to help reset the system.
- Locate the Module: On the Chevrolet Express 2500 Van, the TCM is typically found in the engine compartment on the right-hand (passenger) side.
- Disconnect and Remove: Carefully unclip the electrical connectors from the old TCM. 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 connectors. You should hear a ‘click’ as they lock in.
- Final Steps: Reconnect the negative battery terminal. Start the vehicle and allow it to idle for a few minutes. If you have a basic scan tool, it’s good practice to clear any stored fault codes.
Guaranteed Fitment for Your General Motors Vehicle
While this is a direct-fit solution for the 2006-2014 Express 2500 Van, this versatile T42 module is also compatible with a wide range of GM cars, trucks, and SUVs equipped with 4-speed automatic transmissions like the 4L60E, 4L65E, and 4L80E. Please verify your model below. This part is interchangeable with service numbers including 24252114, 24234503, 24230461, and more.
- ✔ Chevrolet: Express 1500/2500/3500, Silverado 1500/2500, Tahoe, Suburban, Impala, Cobalt, HHR
- ✔ GMC: Savana 1500/2500/3500, Sierra 1500/2500, Yukon, Envoy, Canyon
- ✔ Buick: LaCrosse, Lucerne, Rainier, Rendezvous
- ✔ Cadillac: DTS
- ✔ Pontiac: G6, Grand Prix
- ✔ Saturn: Vue, Aura, Ion
- ✔ Hummer: H3
- ✔ Saab: 9-7X
Frequently Asked Questions
What does ‘VIN Programmed’ actually mean for me?
It means we flash the module with the latest GM software calibrated specifically to your vehicle’s Vehicle Identification Number (VIN). This ensures it works perfectly with your engine, transmission, and existing electronics right out of the box, eliminating the need for a costly and time-consuming programming service at a dealership.
Do I need to send my old TCM back (core charge)?
No, there is absolutely no core charge or need to return your old part. You can dispose of it or keep it, making the process faster and more convenient for you.
Will this fix a P0700 trouble code?
A P0700 code is a generic fault request from the TCM to the main engine computer (ECM) to turn on the check engine light. It’s almost always accompanied by more specific codes stored in the TCM itself. If those specific codes (like for solenoids or communication) are caused by a faulty module, then yes, this part will resolve the root cause of the P0700 code.
Is any other ‘relearn’ procedure required after installation?
In most cases, no. The VIN programming handles the critical calibrations. After installation, the module will perform its own adaptive learning as you drive. Simply drive normally, and the shifting will smooth out as the TCM fine-tunes its strategy over the first 50-100 miles.