Restore Your Avalanche’s Shifting Performance
As a technician with over two decades of experience, I’ve seen countless GM trucks like the 2007-2008 Chevrolet Avalanche 1500 come into the bay with frustrating transmission problems. Drivers report sudden harsh shifts, getting stuck in one gear, or a check engine light that just won’t go away. More often than not, the culprit is a failed Transmission Control Module (TCM). This T42 series module, part number 24240400, is the direct, reliable solution to get your truck’s transmission operating smoothly and predictably again.
The TCM is the brain of your automatic transmission, responsible for managing shift points, torque converter clutch engagement, and line pressure. When it fails, communication breaks down, leading to the poor performance and potential damage you’re experiencing. This isn’t just an annoyance; it’s a safety and reliability issue. Our solution is a high-quality replacement T42 TCM that comes fully programmed to your truck’s specific Vehicle Identification Number (VIN). This critical step ensures it works seamlessly with your vehicle’s systems right out of the box, eliminating the need for an expensive and time-consuming programming session at a dealership.
Is Your Avalanche Exhibiting These Telltale Signs?
A failing TCM can manifest in several ways. If you’re noticing any of the following issues with your 2007-2008 Avalanche 1500 TCM, it’s a strong indicator that this component needs replacement:
- ✔ Harsh, jerky, or erratic gear shifts.
- ✔ The vehicle is stuck in “limp mode” (usually 2nd or 3rd gear).
- ✔ Check Engine Light or Transmission Warning Light is illuminated.
- ✔ Diagnostic Trouble Codes (DTCs) are present, such as P0700 (Transmission Control System Malfunction) or various solenoid-related codes (e.g., P0750, P0753, P0758).
- ✔ Delayed engagement when shifting from Park to Drive or Reverse.
- ✔ A noticeable decrease in fuel economy.
- ✔ Complete failure to shift gears.
From the Diagnostic Bay: A Common Avalanche Scenario
A customer brought in his ’07 Avalanche 1500, complaining it felt like it was “stuck in mud.” It wouldn’t shift past 3rd gear, and the check engine light was on. A quick scan pulled a P0700 and a handful of solenoid circuit codes. In my shop, I’ve seen this exact pattern hundreds of times. While the codes point to solenoids, the root cause is often the TCM itself failing to command them correctly. Instead of a complex and costly internal transmission repair, we installed a VIN-programmed T42 module. Within an hour, the codes were cleared, the truck was shifting perfectly through all gears, and the customer was back on the road, having avoided a multi-thousand-dollar transmission rebuild.
A Straightforward Guide to Installation
Replacing the 2007-2008 Avalanche 1500 TCM is a job most DIY enthusiasts can handle in their own driveway in under 30 minutes. The key is its accessible location and our pre-programming service.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and to help reset the vehicle’s computer systems.
- Locate the Module: On the 2007-2008 Avalanche 1500, the TCM is typically located in the engine compartment, right next to the battery. It’s a silver box with electrical connectors.
- Disconnect and Remove: Carefully unplug the electrical harness connectors 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 the electrical connectors back in, ensuring they click into place.
- Reconnect and Verify: Reconnect the negative battery terminal. Start the vehicle and let it idle for a few minutes. Use a basic OBD2 scan tool to clear any lingering fault codes from the memory. Test drive the vehicle to confirm smooth shifting has been restored.
Verified Vehicle Compatibility
This module is a direct fit for a wide range of General Motors vehicles equipped with 4-speed automatic transmissions like the 4L60E, 4L65E, and 4L70E. While this page is dedicated to the Avalanche, this part is interchangeable with service numbers 24252114, 24234503, 24230461, and many others, fitting the following models:
- AVALANCHE 1500 07-08 Transmission; (next to battery)
- ALLURE 06-09 Transmission; (lower air cleaner housing)
- AURA 07-09 Transmission; (LH frame rail front)
- CANYON 08-12 Transmission; (RH rear engine compartment)
- COBALT 06-10 Transmission; (LH strut tower)
- COLORADO 08-12 Transmission; (RH rear engine compartment)
- DTS 06-11 Transmission; (RH front engine compartment)
- ENVOY 06-09 Transmission; (LH engine compartment)
- EXPRESS 1500/2500/3500 VAN 06-14 Transmission; (RH engine compartment)
- G5 07-10 Transmission; (LH strut tower)
- G6 06-10 Transmission; (LH strut tower)
- GRAND PRIX 06-08 Transmission; (lower air cleaner housing)
- HHR 06-11 Transmission; (LH engine compartment)
- HUMMER H3 08-10 Transmission; (RH rear engine compartment)
- IMPALA 06-11 Transmission; (lower air cleaner housing)
- ION 06-07 Transmission; (behind LH strut tower)
- LACROSSE 06-09 Transmission; (lower air cleaner housing)
- LUCERNE 06-11 Transmission; (LH engine compartment)
- MALIBU 06-10 Transmission; (LH frame rail)
- MONTE CARLO 06-07 Transmission; (lower air cleaner housing)
- MONTANA 06-09 Transmission; (LH strut tower)
- PURSUIT 06 Transmission; (LH strut tower)
- RAINIER 06-07 Transmission
- RENDEZVOUS 06-07 Transmission; (air cleaner box)
- SAAB 9-7X 06-09 Transmission; (LH engine compartment)
- SAVANA 1500/2500/3500 VAN 06-14 Transmission; (RH engine compartment)
- SIERRA 1500/2500 PICKUP 07-13 Transmission; (next to battery)
- SILVERADO 1500/2500 PICKUP 07-13 Transmission; (next to battery)
- SSR 05-06 Transmission; (front LH frame)
- SUBURBAN 1500 07-08 Transmission; (next to battery)
- TAHOE 07-09 Transmission; (next to battery)
- TERRAZA 06-07 Transmission; (LH strut tower)
- TRAILBLAZER 06-09 Transmission; (LH engine compartment)
- UPLANDER 06-09 Transmission; (LH strut tower)
- VUE 07-10 Transmission
- YUKON & YUKON XL 1500 07-09 Transmission; (next to battery)
Frequently Asked Questions
What does ‘VIN Programmed’ actually mean?
It means we load the module with the specific software and calibrations from GM that match your truck’s unique Vehicle Identification Number (VIN). This ensures perfect communication with the engine computer and other systems, for correct shift patterns and performance without any additional setup.
Do I need to take my truck to a mechanic after installing this?
No. Because the module arrives pre-programmed to your VIN, there is no need for a trip to the dealership or a repair shop for programming. It’s designed for plug-and-play installation.
Will this fix a P0700 code on my Avalanche?
A P0700 code indicates a general fault in the transmission control system. While it can be caused by other issues, a failing TCM is a very common cause. If your vehicle is also experiencing shifting problems, replacing the TCM is the most likely solution.
Is there a core charge for my old part?
No, there is no core charge required for this part. You can keep your old module without the hassle of returning it, saving you time and money.
How do I know this is the right part for my truck?
This module, part number 24240400, is the correct fit for the 2007-2008 Chevrolet Avalanche 1500. You can also verify by checking the part number on your existing module. If it matches any of the numbers in our compatibility list, this is the correct replacement.