Fix Your 2007-2009 GMC Yukon’s Transmission Problems for Good
If you’re dealing with the frustration of a GMC Yukon that shifts hard, gets stuck in gear, or has a persistent check engine light, you’ve come to the right place. As a technician with over two decades of experience under the hood, I’ve diagnosed countless transmission issues that trace back to one single component: a failed Transmission Control Module (TCM). This T42 TCM, part number 24238856, is the definitive solution for your 2007-2009 Yukon, arriving at your door pre-programmed to your vehicle’s VIN for a hassle-free, plug-and-play installation.
The TCM is the electronic brain of your 4L60E, 4L65E, or 4L70E automatic transmission. It constantly analyzes data from engine speed, vehicle speed, and throttle position to command precise, smooth shifts. When it fails, the communication breaks down, leading to the jarring and unpredictable performance you’re likely experiencing. Our module restores that critical link, ensuring your transmission operates exactly as the engineers at GM intended.
Is Your Yukon Exhibiting These Telltale Signs?
A failing TCM can manifest in several ways, often mimicking more severe internal transmission problems. Before you consider a costly transmission rebuild, check if your vehicle is showing these common symptoms of a bad TCM:
- ✔ Harsh, erratic, or delayed gear shifts that slam into place.
- ✔ The vehicle is stuck in “limp mode,” refusing to shift out of 2nd or 3rd gear.
- ✔ An illuminated Check Engine Light or Transmission Warning Light on the dash.
- ✔ Diagnostic Trouble Codes (DTCs) stored in the system, such as the generic P0700 or specific solenoid codes like P0750.
- ✔ A noticeable drop in fuel economy due to inefficient shifting.
- ✔ Complete failure to upshift or downshift, or intermittent loss of communication with the module.
A Technician’s Notebook: The Limp Mode Yukon
I remember a 2008 Yukon that came into my shop towed in, stuck in what the owner called “granny gear.” The dashboard was lit up, and the truck wouldn’t go over 30 MPH. He was convinced his transmission was shot and was bracing for a multi-thousand-dollar bill. After plugging in my scan tool, I saw the classic P0700 code. Instead of jumping to conclusions, I checked the TCM. The connectors were fine, but the module itself was unresponsive. We ordered one of these VIN-programmed units. Less than 20 minutes after it arrived, I had it installed, cleared the codes, and took it for a test drive. It shifted perfectly. The customer saved a fortune and drove away with a simple, effective fix. That’s the power of targeting the right component first.
Why Choose a Programmed 2007-2009 Yukon TCM?
The single biggest advantage of this module is our in-house VIN programming service. When you order from us, we flash the module with the latest GM software specific to your Yukon. This means you can skip the expensive trip to the dealership for programming, which can often add hundreds of dollars and days of downtime to your repair. It’s a direct-fit solution designed for both professional mechanics who value efficiency and DIY enthusiasts who want a reliable fix they can perform in their own driveway.
Your Straightforward 30-Minute Installation Guide
Replacing the TCM on your Yukon is a surprisingly simple job that requires only basic hand tools. Here’s a quick guide to get you back on the road:
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work. This prevents short circuits and helps reset the vehicle’s electronic systems.
- Locate the Module: On most 2007-2009 GMC Yukon models, the TCM is conveniently located in the engine bay, typically mounted next to the battery on a bracket.
- Disconnect and Remove: Carefully unclip the wiring harness connectors from the old TCM. Then, unbolt the module from its mounting bracket and remove it from the vehicle.
- Install the New Module: Bolt your new, pre-programmed TCM onto the mounting bracket. Securely reconnect the wiring harnesses, ensuring they click firmly into place.
- Final Steps: Reconnect the negative battery terminal. While the battery disconnect clears many codes, it’s best practice to use a basic OBD2 scan tool to clear any remaining DTCs from the system’s memory. Start the vehicle and enjoy your smooth-shifting transmission!
Verified Fitment for Your General Motors Vehicle
While this is the primary replacement for the 2007-2009 Yukon, this T42 TCM is also compatible with a wide range of GM vehicles. Please verify your part number or consult the list below. This module interchanges with parts 24252114, 24234503, 24238856, and others.
This part will fit these makes and models with these options
AVALANCHE 1500 07-08 Transmission; (next to battery)
CANYON 08-12 Transmission; (RH rear engine compartment)
COLORADO 08-12 Transmission; (RH rear engine compartment)
ENVOY 06-09 Transmission; (LH engine compartment)
EXPRESS/SAVANA VANS 06-14 Transmission; (RH engine compartment)
HUMMER H3 08-10 Transmission; (RH rear engine compartment)
IMPALA 06-11 Transmission; (lower air cleaner housing)
SIERRA 1500 PICKUP 07-13 Transmission; (next to battery)
SILVERADO 1500 PICKUP 07-13 Transmission; (next to battery)
SUBURBAN 1500 07-08 Transmission; (next to battery)
TAHOE 07-09 Transmission; (next to battery)
TRAILBLAZER 06-09 Transmission; (LH engine compartment)
YUKON 07-09 Transmission; (next to battery)
YUKON XL 1500 07-08 Transmission; (next to battery)
…and many more GM cars, trucks, and SUVs from 2006-2014.
Do I need to program this module?
Do I need to program this module?
No. We handle all the programming for you. Simply provide your vehicle’s VIN during checkout, and the module will arrive ready for immediate installation with no extra steps required.
Where is the TCM located on my 2008 GMC Yukon?
On the 2007-2009 GMC Yukon, the Transmission Control Module (TCM) is typically found in the engine compartment, mounted on a bracket right next to the battery.
Will this fix a P0700 trouble code?
In many cases, yes. The P0700 code is a general fault code indicating the TCM has detected a problem. If the TCM itself is the source of the failure, replacing it with this unit will resolve the code and the underlying issue.
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, saving you time and return shipping costs.
What is your warranty policy?
We stand behind the quality of our parts. This transmission control module comes with a one-year warranty, giving you peace of mind with your purchase.