Is Your Trailblazer Shifting Erratically?
If your 2006 Chevrolet Trailblazer EXT is suffering from harsh shifting, getting stuck in gear, or has an illuminated Check Engine Light with transmission codes, you’re likely dealing with a failed Transmission Control Module (TCM). The TCM is the electronic brain of your automatic transmission, responsible for orchestrating every gear change and ensuring smooth, efficient operation. When it fails, it can cause a wide range of frustrating and potentially damaging drivability issues. This genuine quality T42 TCM, service number 24240449, is the definitive solution to restore your vehicle’s transmission performance to factory specifications.
From the Diagnostic Bay
We had a 2006 Trailblazer EXT come into the shop that the owner was convinced needed a full transmission rebuild. It was slamming into gear and would occasionally get stuck in what felt like third gear (limp mode). He had already replaced two shift solenoids based on some forum advice, with no change. After a quick scan, we saw the classic P0700 code, indicating a general transmission fault, along with several erratic solenoid circuit codes. Instead of tearing down the transmission, we checked the TCM’s live data and saw nonsensical readings. A new, programmed TCM fixed everything in under an hour. The customer was thrilled to have saved thousands on an unnecessary transmission rebuild. It’s a classic case of symptoms pointing to a major mechanical failure when the root cause is actually electronic.
Key Symptoms of a Failing GM T42 TCM
- ✔ Hard, jerky, or delayed gear shifts that disrupt your driving experience.
- ✔ The vehicle enters “limp mode,” often getting stuck in 2nd or 3rd gear.
- ✔ Check Engine Light or Transmission Warning Light is on, with Diagnostic Trouble Codes (DTCs) like P0700, P0750, P0753, P0758, or other solenoid-related faults.
- ✔ Inability to upshift or downshift, leading to poor acceleration and high RPMs.
- ✔ A noticeable decrease in fuel economy as the transmission operates inefficiently.
- ✔ Intermittent loss of communication with the TCM, causing unpredictable behavior.
The Ultimate Solution: A VIN-Programmed Replacement
Don’t settle for a generic module that requires an expensive trip to the dealership for programming. We take the hassle out of the repair process. This T42 TCM is expertly pre-programmed to your Trailblazer EXT’s specific Vehicle Identification Number (VIN). This critical step ensures that the module has the latest GM software and is perfectly calibrated for your vehicle’s engine, transmission (4L60E, 4L65E, 4L70E), and tire size. The result is a true plug-and-play installation that restores precise shift points, proper torque converter lockup, and reliable performance right out of the box. Getting the right 2006 Trailblazer EXT TCM is crucial for a lasting repair.
Installation and Compatibility Information
Replacing the 2006 Trailblazer EXT TCM is a straightforward job for a confident DIYer or any professional technician. On the 2006 Trailblazer EXT with an 8-cylinder engine, the module is typically located in the left-hand (driver’s side) engine compartment, making it easily accessible. The entire process usually takes less than 30 minutes. Simply disconnect the battery, unplug the electrical connectors from the old module, unbolt it, and install the new one in its place. Once the new module is connected and the battery is reconnected, the vehicle is ready to go. We recommend using a basic scan tool to clear any stored DTCs after installation.
This module is a direct replacement for a wide array of GM vehicles from 2006-2014 and interchanges with numerous part numbers, including: 24252114, 24234503, 24230461, 24234274, 24235340, 24235754, 24238856, 24239224, 24240449, and many more. It’s the ideal part for restoring performance in vehicles like the Chevrolet Silverado, Tahoe, GMC Sierra, Yukon, Cadillac DTS, and Pontiac G6, among others.
Frequently Asked Questions
What exactly does the T42 TCM do?
The Transmission Control Module (TCM) acts as the central computer for your automatic transmission. It processes data from various sensors (like vehicle speed, engine RPM, and throttle position) to determine the perfect moment to shift gears, control hydraulic pressure, and manage the torque converter lockup clutch for optimal performance and fuel efficiency.
Is this module really plug-and-play?
Yes. Because we pre-program the module to your vehicle’s specific VIN before shipping, it is ready for immediate installation. No further programming or dealership visits are required. This saves you time and significant expense.
Where is the TCM located on my 2006 Trailblazer EXT?
For the 2006 Trailblazer EXT equipped with the 8-cylinder engine, the TCM is found in the engine compartment on the driver’s side (LH side). Its location makes it relatively easy to access and replace without specialized tools.
Will this part fix a P0700 trouble code?
A P0700 code is a generic fault code that simply means the TCM has detected a problem and has requested the Check Engine Light to be turned on. While a faulty TCM itself can cause a P0700, it’s often accompanied by more specific codes. This module will resolve the issue if the TCM is the root cause of the fault codes being stored.
Do I need to send my old TCM back?
No, there is no core charge associated with this part. You can keep your old module, which eliminates the hassle and expense of return shipping.