Is your 2006-2011 Buick Lucerne suffering from harsh, erratic shifting, or worse, stuck in limp mode? As a technician with over two decades of experience, I’ve seen these symptoms countless times, and the culprit is almost always a failing Transmission Control Module (TCM). The Lucerne is built for a smooth, comfortable ride, and a faulty TCM can completely ruin that experience. This pre-programmed T42 Transmission Control Module is the definitive solution to restore your car’s performance and get you back on the road with confidence.
This isn’t just a replacement part; it’s a complete, ready-to-install fix. We handle the complex part for you by programming the module to your vehicle’s specific VIN before it ships. This means no expensive trips to the dealership for programming, no special tools, and no headaches. It’s designed to directly address the root cause of many common transmission issues, ensuring your automatic transmission operates exactly as the factory intended.
Diagnosing and Solving Common Transmission Faults
When a 2006-2011 Lucerne TCM begins to fail, it can manifest in ways that are both annoying and dangerous. From delayed gear engagement when you’re pulling into traffic to a complete loss of shifting capability, these issues should not be ignored. This module is engineered to resolve those problems by restoring precise communication between your engine and transmission, ensuring smooth gear changes, correct torque converter lockup, and reliable performance.
Case Study: A Tricky Diagnosis
A customer brought in their ’09 Lucerne complaining of intermittent ‘no-shift’ conditions and a check engine light. They’d been to another shop that couldn’t pinpoint the problem. My scan tool pulled a P0700 (Transmission Control System Malfunction) and a few solenoid circuit codes. Instead of just throwing solenoids at it, I checked the TCM connectors for corrosion—they were clean. I knew from experience that on these GM platforms, the internal logic of the T42 module can fail, causing these ghost codes. We installed one of our VIN-programmed modules, cleared the codes, and the car drove perfectly. The customer saved hundreds by avoiding an unnecessary internal transmission repair.
Is Your Buick Lucerne Showing These Telltale Signs?
- ✔ Harsh, banging shifts or delayed gear engagement.
- ✔ Vehicle is stuck in a single gear (limp mode), often 2nd or 3rd.
- ✔ Check Engine Light or Transmission Warning Light is illuminated.
- ✔ Diagnostic Trouble Codes (DTCs) are present, such as P0700, P0751, P0756, or other solenoid-related faults.
- ✔ A sudden drop in fuel economy or a feeling of sluggishness.
- ✔ Complete failure to shift up or down.
A Straightforward Guide to Installation
For the confident DIYer or professional mechanic, installing this 2006-2011 Lucerne TCM is a simple process that typically takes less than 30 minutes. On the Lucerne, it’s conveniently located in the left-hand (driver’s side) of the engine compartment.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and to help reset the system.
- Locate the Module: Find the TCM in the LH engine compartment. It’s a silver box with electrical connectors.
- Disconnect and Remove: Carefully unclip the wiring harnesses. Then, unbolt the old module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCM into place and securely reconnect the wiring harnesses. Ensure they click into place.
- Final Steps: Reconnect the battery terminal. While the module is plug-and-play, it’s always best practice to use a standard OBDII scan tool to clear any stored fault codes from the vehicle’s memory.
Verified Vehicle Compatibility
This module, part number 24238856, is a direct replacement for a wide range of General Motors vehicles equipped with the T42 controller. While this page is focused on the 2006-2011 Lucerne TCM, it also fits the following models. Please verify your specific model and options below.
This part will fit these makes and models with these options
ENVOY 08-09 Transmission; (LH engine compartment)
SAVANA 3500 VAN 06-14 Transmission; (RH engine compartment)
VUE 07-08 Transmission; 2.4L, (LH front engine compartment)
G5 07-10 Transmission; (LH strut tower)
SIERRA 1500 PICKUP 07 Transmission; (new style, smooth door skin), (next to battery)
LUCERNE 06-07 Transmission; (4.6L), (LH engine compartment)
VUE 09 Transmission; 2.4L, w/hybrid, LH side front engine compartment, (shift control)
VUE 10 Transmission
TAHOE 08-09 Transmission; (next to battery), w/o auxiliary oil cooler pump
YUKON XL 1500 07-08 Transmission; (next to battery)
AURA 07-09 Transmission; (LH frame rail front)
RENDEZVOUS 06-07 Transmission; (air cleaner box)
SAAB 9-7X 06-09 Transmission; (LH engine compartment)
SAVANA 2500 VAN 06-14 Transmission; (RH engine compartment)
ALLURE 06-09 Transmission; (lower air cleaner housing)
LUCERNE 08-11 Transmission; (LH engine compartment)
RAINIER 06-07 Transmission
SILVERADO 1500 PICKUP 07 Transmission; (new style, smooth door skin), (next to battery)
SILVERADO 1500 PICKUP 09-13 Transmission; (next to battery), w/o hybrid option
YUKON 09 Transmission; (next to battery), w/o auxiliary oil cooler pump
ENVOY 06-07 Transmission; (LH engine compartment), (8 cylinder)
MONTE CARLO 06-07 Transmission; (lower air cleaner housing)
YUKON 08 Transmission; (next to battery), w/o auxiliary oil cooler control
EXPRESS 1500 VAN 06-14 Transmission; (RH engine compartment)
SSR 05-06 Transmission; (front LH frame)
SAVANA 1500 VAN 06-14 Transmission; (RH engine compartment)
SIERRA 1500 PICKUP 09-13 Transmission; (next to battery), w/o hybrid option
EXPRESS 3500 VAN 06-14 Transmission; (RH engine compartment)
ION 06-07 Transmission; (behind LH strut tower)
PURSUIT 06 Transmission; (LH strut tower)
TAHOE 07 Transmission; (next to battery)
ENVOY XL 06 Transmission; (LH engine compartment), (8 cylinder)
EXPRESS 2500 VAN 06-14 Transmission; (RH engine compartment)
IMPALA 06-11 Transmission; (lower air cleaner housing)
MONTANA 06-09 Transmission; (LH strut tower)
TRAILBLAZER 08-09 Transmission; (LH engine compartment)
YUKON 07 Transmission; (next to battery)
G6 06-10 Transmission; (LH strut tower)
HHR 06-11 Transmission; (LH engine compartment)
TRAILBLAZER 06-07 Transmission; (LH engine compartment), (8 cylinder)
AVALANCHE 1500 07-08 Transmission; (next to battery)
COBALT 06-10 Transmission; (LH strut tower)
SIERRA 1500 PICKUP 08 Transmission; (next to battery)
SILVERADO 1500 PICKUP 08 Transmission; (next to battery)
LACROSSE 06-09 Transmission; (lower air cleaner housing)
SIERRA 2500 PICKUP 07 Transmission; new style (smooth door skin), 6.0L, (next to battery)
SILVERADO 2500 PICKUP 07 Transmission; new style (smooth door skin), 6.0L, (next to battery)
COLORADO 08-12 Transmission; (RH rear engine compartment)
SUBURBAN 1500 07-08 Transmission; (next to battery)
VUE 09 Transmission; 2.4L, w/o hybrid; (LH front engine compartment)
CANYON 08-12 Transmission; (RH rear engine compartment)
DTS 06-11 Transmission; (RH front engine compartment)
MALIBU 06-10 Transmission; (LH frame rail)
GRAND PRIX 06-08 Transmission; (lower air cleaner housing)
HUMMER H3 08-10 Transmission; (RH rear engine compartment)
TERRAZA 06-07 Transmission; (LH strut tower)
TRAILBLAZER EXT 06 Transmission; (LH engine compartment), (8 cylinder)
UPLANDER 06-09 Transmission; (LH strut tower)
Frequently Asked Questions
What does ‘VIN Programmed’ actually mean for me?
It means the module arrives ready for installation. We load the latest GM-certified software specific to your car’s Vehicle Identification Number (VIN) onto the module. This ensures it communicates perfectly with your car’s other systems, just like a part from the dealer, but without the extra cost and appointment for programming.
Will this part fix my car being stuck in limp mode?
Yes, in the vast majority of cases. Limp mode is a protective measure triggered by the computer when it detects a serious transmission fault. A failing TCM is one of the most common causes. Replacing it with this functional, programmed unit should restore normal shifting operation.
Is this a difficult part to install myself?
For most people with basic hand tools and some mechanical comfort, this is a very straightforward job. Locating it in the engine bay, disconnecting the battery, and swapping the module can be done in under an hour. No complex procedures are required.
Do I need to send my old part back (core charge)?
No, there is absolutely no core charge or need to return your old module. You can keep it or dispose of it at your convenience.
What kind of warranty comes with this part?
This module is backed by our one-year, hassle-free warranty. We stand by the quality and reliability of our programmed electronics, giving you peace of mind with your purchase.