Programmed 2005 LaCrosse TCM YJHY Transmission Control Module

Restore Smooth, Reliable Shifting to Your GM Vehicle

If you’re dealing with the frustration of a transmission that slams into gear, refuses to shift, or has put your car into a performance-limiting “limp mode,” you’ve come to the right place. As a technician with over two decades of experience under the hood, I’ve seen firsthand how a failing Transmission Control Module (TCM) can mimic a catastrophic transmission failure, leading to stress and expensive misdiagnoses. This isn’t just a part; it’s the solution to get your vehicle driving like it should again.

This is a direct-fit replacement TCM for a wide range of 2005 GM vehicles, including the Buick LaCrosse. The biggest challenge with replacing these modules has always been the expensive and time-consuming trip to the dealership for programming. We eliminate that step completely. Before this module ships, we will flash it with the latest official GM software, specifically matched to your vehicle using your VIN. This ensures perfect communication between your engine, transmission, and other onboard computers, restoring the precise shift logic your car was designed with. When you install this 2005 LaCrosse TCM, you’re not just replacing a failed part—you’re installing confidence.

From the Diagnostic Bay: A Costly Misdiagnosis Avoided

A customer once brought in their 2005 Buick Allure (which uses the same TCM as the LaCrosse) with a quote for over $3,000 for a transmission rebuild from another shop. The car was shifting violently from 1st to 2nd and had a P0700 trouble code. I scanned the vehicle and found specific solenoid circuit codes stored in the TCM. Knowing the history of these modules, I recommended we start by replacing the TCM. After installing one of our pre-programmed modules—a 30-minute job—the car shifted perfectly. The customer saved thousands of dollars and a lot of unnecessary work by correctly identifying the electronic brain, not the mechanical guts, as the source of the problem.

Is Your Transmission Acting Up? Common Failure Signs

A faulty TCM can cause a variety of symptoms that are often mistaken for internal transmission problems. If your vehicle is experiencing any of the following, a failing module is a likely culprit:

✔ Harsh, erratic, or delayed shifting
✔ Vehicle stuck in one gear (often called “limp mode”)
✔ Check Engine Light or Transmission Warning Light is on
✔ False overheating warnings or inaccurate temperature readings
✔ Complete loss of communication with the scan tool
✔ Diagnostic Trouble Codes (DTCs) such as P0700, U0101, or specific solenoid codes (e.g., P0751, P0756, P0973).

A Straightforward Guide to Installation

Installing your new 2005 LaCrosse TCM is a manageable job for a DIY enthusiast. On the LaCrosse with the 3.6L engine, the module is conveniently located under the air cleaner housing, making access relatively simple.

Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
Access the Module: Locate and remove the air cleaner assembly. This will typically involve loosening a few clamps and bolts to lift the housing out of the way.
Disconnect the Old TCM: Carefully unplug the electrical connectors from the old module. There are usually locking tabs that need to be depressed or slid to release the harnesses.
Remove the Old TCM: Unbolt the old module from its mounting bracket.
Install the New TCM: Mount your new, pre-programmed TCM onto the bracket and securely fasten the bolts.
Reconnect Everything: Plug the electrical connectors firmly into the new module until they click into place. Reinstall the air cleaner assembly.
Final Step: Reconnect the negative battery terminal. It’s a good practice to clear any old codes with a basic scan tool, but your vehicle is now ready to be driven.

Verified Vehicle Compatibility

This module is a direct replacement for multiple part numbers and is guaranteed to fit the following vehicles. Please ensure your vehicle and options match the list below. This part is a direct replacement for part numbers: 24223112, 24226863, 24233595, 24234189, 24239427, YBWW, YDFC, YDFD, YDLT, YJHY, YKTB, YKTF.

2005 Buick Allure: (lower air cleaner housing)
2005 Buick LaCrosse: with 3.6L engine (lower air cleaner housing)
2005 Buick Rainier: Transmission
2005 Chevrolet Cobalt: (behind LH strut tower)
2005 Chevrolet Corvette: (LH frame rail)
2005 Chevrolet Trailblazer EXT: with 8 cylinder (LH engine compartment)
2005 GMC Envoy / Envoy XL / Envoy XUV: with 8 cylinder (LH engine compartment)
2005 Pontiac GTO: Transmission
2005 Pontiac Grand Prix: (lower air cleaner housing)
2005 Pontiac Pursuit: (behind LH strut tower)
2005 Saturn ION: (behind LH strut tower)
2004-2005 Buick Rendezvous: with 3.6L engine (air cleaner box)

By purchasing this 2005 LaCrosse TCM, you are getting a reliable, plug-and-drive part that solves frustrating transmission issues and saves you from an expensive and unnecessary trip to the dealer. Just provide your VIN at checkout, and we’ll handle the rest.