If your 2007-2008 Chevrolet Avalanche 1500 is suffering from erratic shifting, getting stuck in gear, or has the dreaded check engine light on with transmission codes, you’ve come to the right place. As a technician with over two decades of experience under the hood, I’ve seen countless drivers frustrated by these exact issues. The problem often points directly to a failing Transmission Control Module (TCM), the electronic brain of your automatic transmission.
This T42 Transmission Control Module, part number 24239224, is the definitive solution for restoring crisp, reliable shifting to your truck. It’s not just a replacement part; it’s a complete fix. We handle the most critical step for you: VIN programming. By programming the module to your truck’s specific Vehicle Identification Number before it ships, we eliminate the need for an expensive trip to the dealership for programming. This makes the installation a true plug-and-play process, saving you time and money.
Is Your Avalanche Exhibiting These Transmission Faults?
A faulty TCM can manifest in several ways. From my experience in the service bay, these are the most common red flags that point to a failing module. If you’re noticing any of these, a new TCM is likely the solution.
- ✔ Harsh, slamming shifts or delayed gear engagement.
- ✔ The vehicle is stuck in “limp mode,” often refusing to shift out of 2nd or 3rd gear.
- ✔ Check Engine Light or Transmission Warning Light is illuminated with Diagnostic Trouble Codes (DTCs) like P0700, P0750, or other solenoid-related faults.
- ✔ Inconsistent or complete failure to upshift or downshift.
- ✔ A noticeable drop in fuel economy or signs of the transmission overheating.
- ✔ Intermittent loss of communication with the module, causing unpredictable behavior.
Case Study: A Tricky Diagnosis
A customer brought in a 2008 Silverado with classic transmission failure symptoms—stuck in 3rd gear, P0700 code. Another shop had quoted him for a full transmission rebuild, a multi-thousand dollar job. I hooked up my professional scan tool and saw communication errors with the TCM. Before condemning the transmission itself, I suggested we try a pre-programmed TCM. It’s a common failure point on these GM platforms. We swapped the module in about 20 minutes, cleared the codes, and the truck shifted perfectly. The customer saved thousands and drove away with a reliable truck. This is why properly diagnosing the electronics first is so critical.
DIY-Friendly Installation in Under 30 Minutes
Replacing the TCM on your 2007-2008 Avalanche 1500 is a straightforward job that most DIYers can handle with basic tools. Because our module arrives pre-programmed, you skip the most complicated part of the process.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and to help reset the vehicle’s electronic systems.
- Locate the Module: On your Avalanche, the TCM is typically located in the engine bay, mounted next to the battery. It’s a silver box with electrical connectors.
- Disconnect and Remove: Carefully unplug the electrical harnesses from the old TCM. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, VIN-programmed TCM into place. Securely plug in the electrical connectors until they click.
- Reconnect and Verify: Reconnect the negative battery terminal. Start the vehicle and allow it to idle for a few minutes. Use a basic scan tool to clear any stored DTCs if they persist. Take a test drive to confirm smooth shifting has been restored.
Verified Fitment for Your GM Truck or SUV
This T42 module is a direct-fit replacement for a wide range of General Motors vehicles equipped with 4-speed automatic transmissions like the 4L60E, 4L65E, and 4L70E. It is an interchange for part numbers 24239224, 24252114, 24234503, and more. While this page focuses on the 2007-2008 Avalanche 1500 TCM, it also fits the following models:
- ✔ Chevrolet Silverado, Tahoe, Suburban, Express, Colorado, HHR, Cobalt, Impala
- ✔ GMC Sierra, Yukon, Savana, Canyon, Envoy
- ✔ Cadillac DTS, Buick LaCrosse, Lucerne
- ✔ Pontiac G6, Grand Prix
- ✔ Hummer H3, Saab 9-7X, Saturn Vue
Frequently Asked Questions
Do I need to do any programming or flashing myself?
No. This module is fully programmed to your vehicle’s VIN before shipping. It is ready for installation right out of the box, with no need for a trip to the dealer or a special scan tool for programming.
Is there a core charge for this part?
No, there is no core charge. You are not required to send your old, faulty module back to us, which simplifies the process for you.
Will this fix a P0700 trouble code?
A P0700 code is a general transmission fault request from the TCM to the main engine computer (ECM) to turn on the check engine light. While this module often resolves the underlying issue causing the P0700, it’s important to scan for more specific P-codes (like P0751, P0756, etc.) to confirm the diagnosis. In many cases, replacing a faulty TCM will clear this and related codes.
Where is the TCM located on a 2007 Avalanche?
On the 2007-2008 Chevrolet Avalanche 1500, the Transmission Control Module is conveniently located in the engine compartment, right next to the battery. This makes for a very accessible and quick replacement.