If your 2007-2008 Chevrolet Avalanche is suffering from harsh, erratic shifting, getting stuck in gear, or throwing transmission codes, you’ve likely pinpointed the culprit: a failing Transmission Control Module (TCM). As a technician with over two decades of experience, I’ve seen countless GM trucks and SUVs sidelined by this exact issue. The T42 TCM is the brain of your automatic transmission, and when it fails, it creates frustrating and potentially unsafe driving conditions. This isn’t just an inconvenience; it’s a critical component for your vehicle’s health and your peace of mind.
This is your direct, no-hassle solution. We are offering a high-quality replacement T42 Transmission Control Module, specifically for your truck, that comes fully pre-programmed to your vehicle’s unique VIN. This means you can skip the expensive trip to the dealership and the extra cost of programming. This is a true plug-and-play fix designed for both professional mechanics and determined DIYers. It restores the precise, smooth shifting you expect from your Avalanche, directly addressing common Diagnostic Trouble Codes (DTCs) and performance problems right out of the box.
Case Study: A Tricky Diagnosis
A customer brought in his 2008 Silverado 1500—a very similar platform to your Avalanche—with a classic complaint: it was stuck in ‘limp mode’ (3rd gear only) and the check engine light was on. His scanner showed a P0700 (Transmission Control System Malfunction) and a few solenoid-specific codes. He’d already replaced two shift solenoids with no change. The problem wasn’t mechanical; it was electronic. The original TCM was sending faulty signals. We installed one of our pre-programmed T42 modules. In less than 20 minutes, after a quick battery disconnect and reconnect, the truck was shifting perfectly through all gears. He saved hundreds by avoiding dealership programming fees and got a reliable fix the first time.
Is Your Avalanche Exhibiting These Telltale Signs?
A failing 2007-2008 Avalanche 1500 TCM will make its presence known. If you’re experiencing any of the following, it’s time to consider a replacement:
- âś” Harsh, slamming shifts or jerky gear engagement.
- âś” The vehicle is stuck in one gear (often called ‘limp mode’).
- âś” Check Engine Light or Transmission Warning Light is illuminated.
- âś” Diagnostic codes like P0700, P0750, P0753, P0758, or other solenoid circuit faults are present.
- âś” Failure to upshift or downshift as expected.
- âś” A noticeable decrease in fuel economy.
- âś” Intermittent loss of communication with the module (seen with a high-end scan tool).
Quick & Easy TCM Installation Guide
You don’t need a professional lift or a full day to get this job done. For the 2007-2008 Avalanche, the TCM is conveniently located in the engine bay, making for a straightforward swap.
- Safety First: Disconnect the negative terminal from your truck’s battery to prevent any electrical shorts and to help reset the system.
- Locate the Module: On your Avalanche, the TCM is typically mounted right next to the battery in the engine compartment. It’s a silver box with electrical connectors.
- Disconnect and Remove: Carefully unplug the electrical harness connectors. They have locking tabs that need to be released. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCM into place. Securely plug in the electrical connectors until they click, ensuring a solid connection.
- 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. Take a test drive to confirm the smooth shifting performance.
Verified Fitment For These GM Vehicles
While this part is a perfect match for the 2007-2008 Avalanche 1500 TCM, it is also compatible with a wide range of other GM vehicles that use the T42 controller. It interchanges with part numbers 24242391, 24234503, 24252114, 24235753, and more. Key compatible models include:
- âś” Chevrolet Avalanche 1500 (2007-2008)
- âś” Chevrolet Silverado & GMC Sierra 1500/2500 (2007-2013)
- âś” Chevrolet Tahoe & GMC Yukon (2007-2009)
- âś” Chevrolet Suburban 1500 (2007-2008)
- âś” Chevrolet Express & GMC Savana Vans (2006-2014)
- âś” Hummer H3 (2008-2010)
- âś” Cadillac DTS (2006-2011)
- âś” And many other GM cars, trucks, and SUVs from 2006-2014.
Do I need to take this part to the dealer for programming?
Do I need to take this part to the dealer for programming?
No. This is the biggest benefit of our service. We pre-program the module to your vehicle’s specific VIN before shipping. This makes the installation plug-and-play, saving you time and the high cost of dealership programming.
Where is the TCM located on my 2007 Avalanche?
On the 2007-2008 Chevrolet Avalanche 1500, the Transmission Control Module is located in the engine compartment, mounted on a bracket right next to the battery.
Will this fix a P0700 trouble code?
A P0700 code is a general fault code indicating the TCM has detected a problem. Often, the problem is the TCM itself. While this module is a very common fix for a P0700, especially when accompanied by other transmission codes, you should ensure there are no underlying wiring or solenoid issues. In the vast majority of cases I’ve seen, a faulty module is the root cause.
Is there a core charge for my old 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.