Is Your GMC Yukon’s Transmission Acting Up?
There’s nothing more frustrating than when your dependable 2007-2009 GMC Yukon starts shifting harshly, hesitating between gears, or worse, gets stuck in limp mode. Many owners immediately fear a catastrophic transmission failure, thinking a multi-thousand dollar rebuild is in their future. But after 20 years of diagnosing these exact issues, I can tell you that the problem is often not the transmission itself, but its brain: the Transmission Control Module (TCM).
Just last month, a 2008 Yukon was towed to my shop. The owner was distraught; it wouldn’t shift out of 3rd gear, the check engine light was on, and another shop had quoted him for a full transmission replacement. A quick diagnostic scan showed classic TCM communication error codes. Instead of a massive repair, we installed a VIN-programmed T42 module. In less than an hour, the truck was shifting perfectly, and the customer saved thousands. This is an incredibly common scenario for these vehicles.
Common Symptoms of a Failing GM T42 TCM:
- โ Harsh or Erratic Shifting: Abrupt, jerky gear changes or unpredictable shifting patterns.
- โ Stuck in Gear / Limp Mode: The transmission defaults to 2nd or 3rd gear to prevent further damage.
- โ Delayed Engagement: A noticeable pause when shifting from Park into Drive or Reverse.
- โ Warning Lights: Check Engine Light or a dedicated transmission warning light on the dash, often with codes like P0700 or various solenoid faults (P0750, P0751, etc.).
- โ Poor Fuel Economy: Inefficient shifting and torque converter lock-up issues can cause a significant drop in MPG.
- โ No Communication: A scan tool may be unable to communicate with the transmission module.
Expert Pro Tip: Check Your Connections First
Before installing your new module, take a moment to inspect the large electrical connector harness that plugs into the TCM. On these GM trucks, years of exposure to heat and moisture can cause corrosion on the pins. Use a small brush and quality electrical contact cleaner to ensure the connection is pristine. A poor connection can mimic the symptoms of a failed TCM, and this simple five-minute check ensures your new part works flawlessly from the start.
The Solution: A Reliable, Pre-Programmed 2007-2009 Yukon Transmission Module
This OEM-quality T42 TCM is the definitive fix for these issues. The most critical feature is our complimentary VIN programming service. We flash the module with your Yukon’s specific Vehicle Identification Number and the latest GM software updates before it ships. This means it arrives ready for a true plug-and-play installation, eliminating the need for an expensive trip to the dealership for programming.
Plug-and-Play Installation: No Dealer Visit Required
You can perform this repair right in your driveway in under 30 minutes with basic hand tools. Hereโs a simple guide for your Yukon:
- Safety First: Always disconnect the negative terminal from your vehicle’s battery.
- Locate the TCM: On the 2007-2009 Yukon, the module is conveniently located in the engine compartment, typically mounted right next to the battery.
- Disconnect and Remove: Carefully unclip and unplug the electrical connectors. Be gentle with the locking tabs. Then, unbolt the old module from its mounting bracket.
- Install the New Module: Bolt your new, pre-programmed module in place and securely reconnect the electrical harnesses. You should hear a ‘click’ as they lock.
- Reconnect and Verify: Reconnect the negative battery terminal. Start the engine and take the vehicle for a test drive to confirm that the shifting is smooth and responsive. Any old trouble codes can be cleared with a basic OBD2 scan tool.
Part Specifications and Compatibility
- โ Direct Fit: Designed to meet or exceed original equipment standards for your 2007-2009 Yukon.
- โ No Core Charge: Keep your old part; there’s no need to send it back.
- โ Warranty: Comes with a one-year warranty for your peace of mind.
- โ Interchangeable Part Numbers: Replaces a wide range of part numbers, including 24235732, 24252114, 24234503, 24230461, 24234274, 24235340, 24235754, 24238856, 24239224, 24240400, and more.
Don’t let a faulty TCM keep your GMC Yukon off the road. Order this pre-programmed transmission control module today and restore the smooth, reliable performance you expect.