Guide to the 2005-2009 Buick LaCrosse Automatic Transmission Control Solenoid
Experiencing hard shifts or transmission hesitation? Your LaCrosse's shift solenoids might be the issue.
- Harsh shifting is the number one symptom of a failing shift solenoid in the 2005-2009 LaCrosse.
- The repair is labor-intensive; expect labor to be the most expensive part of the job.
- It is highly recommended to replace the shift solenoids in pairs (A & B) to avoid a repeat repair.
- No safety recalls have been issued for this specific transmission problem, though other non-related recalls exist.
Understanding Transmission Solenoid Problems in Your LaCrosse
If you own a 2005-2009 Buick LaCrosse, you might eventually face issues with the automatic transmission. A common point of failure is the set of control solenoids, often called shift solenoids. These parts control when and how your car shifts gears. When one or more solenoids start to fail, you'll notice significant changes in how your car drives, such as harsh shifting, delayed gear engagement, or the transmission getting stuck in one gear.
Common Symptoms of a Failing Solenoid
A bad shift solenoid can make your LaCrosse difficult or unpleasant to drive. Here are the most common signs that you have a problem:
🎬 Watch this video to learn more about common solenoid failure symptoms.- Harsh or Abrupt Shifting: The most frequently reported issue is a hard "thud" or "clunk" when the transmission shifts, especially between 1st and 2nd gear. This happens because a failing solenoid isn't regulating fluid pressure correctly.
- Delayed Shifting: You might notice a long pause after the engine revs up before the transmission finally shifts into the next gear.
- Check Engine Light: A failing solenoid will often trigger a diagnostic trouble code (DTC) and illuminate the check engine light on your dashboard. Common codes include P0750 through P0770.
- Stuck in Gear or "Limp Mode": In more serious cases, the transmission may get stuck in a single gear (often 2nd or 3rd) to protect itself from further damage.
Is It a Solenoid or Something More?
While solenoids are a common failure point, symptoms like harsh shifting can also be caused by other issues within the 4T65-E transmission, such as problems with the pressure control solenoid or even internal clutch wear. A proper diagnosis with a scan tool is crucial before buying parts.
Choosing the Right Aftermarket Solenoid
When replacing your LaCrosse's transmission solenoids, you have options. The original parts are made by ACDelco, GM's parts division. However, several aftermarket brands offer quality replacements that can save you money. For the 2005-2009 LaCrosse, two shift solenoids (Solenoid A and Solenoid B) are used, and they are often replaced as a pair.
Here's a look at the available brands:
- Standard Ignition (SMP): A well-regarded brand in the aftermarket industry, Standard Ignition produces a wide range of engine management parts. Their solenoids are engineered to meet or exceed OE specifications, often featuring copper windings and precision-machined surfaces for reliability. They are a solid choice for a dependable repair.
- ATP (Automatic Transmission Parts): ATP specializes in transmission components and offers a range of aftermarket solutions. While they provide a cost-effective alternative, some users have reported occasional quality control issues with packaging on other types of parts, so inspect the part carefully upon arrival. 🎬 See a review of ATP transmission service kits and gaskets.
- Pioneer Cable: Pioneer offers various automotive parts, including transmission components. Reviews are mixed and often for different parts like cables, with some customers satisfied with the fit and function while others note differences in quality compared to OEM parts. They are generally considered a budget-friendly option.
Pro Tip: Replace in Pairs
The 4T65-E transmission uses two primary shift solenoids (A and B) that are identical parts. Mechanics often recommend replacing both at the same time. If one has failed due to age and use, the other is likely not far behind. This saves you from having to pay for the same labor-intensive repair twice in a short period.
Estimated Costs for Solenoid Replacement
The cost of the parts is only one piece of the puzzle. Replacing the solenoids on a 4T65-E transmission is a labor-intensive job.
| Item | Estimated Cost |
|---|---|
| New Aftermarket Solenoids (Pair) | $40 - $120 |
| Shop Labor | $600 - $900 |
| Total Estimated Cost 🎬 Learn more about shift solenoid symptoms and typical replacement costs. | $640 - $1020 |
Note: Labor costs can vary significantly based on your location and the specific shop. This repair requires removing the side cover of the transmission, which involves taking apart a portion of the driver's side suspension.
Frequently Asked Questions
Are there any recalls for the 2005-2009 LaCrosse transmission?
No, there are no specific recalls for the transmission solenoids or the transmission itself on the 2005-2009 Buick LaCrosse. There was a major recall (NHTSA ID: 14V355) related to the ignition switch, but it does not involve the transmission components.
Can I replace the transmission solenoids myself?
This is an advanced DIY repair. Accessing the solenoids requires removing the driver-side wheel, axle, and other suspension components to get the transmission side cover off. It requires specialized tools and a good amount of mechanical experience. For most owners, this job is best left to a professional mechanic.
Should I buy OEM or aftermarket solenoids?
For this specific repair, high-quality aftermarket brands like Standard Ignition offer a reliable alternative to more expensive OEM parts. Given the high labor cost, it's wise to invest in a quality part to avoid having to do the job again. Budget-tier parts may be less reliable, and the savings on the part itself may not be worth the risk of premature failure.
Will a transmission fluid change fix a solenoid problem?
In some rare cases, if the issue is caused by dirty fluid or minor clogging, a fluid and filter change might temporarily improve symptoms. However, if the solenoid is electrically faulty or mechanically stuck, a fluid change will not fix it. It is a diagnostic step but rarely a permanent solution for solenoid-specific error codes.
Helpful Videos
Technical Specifications
OEM Part Numbers: 24219819 10478124
Fits the GM 4T65-E 4-Speed Automatic Transmission. Two shift solenoids (A & B) are required for a complete replacement.
We Have This Part in Stock
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- Buick LaCrosse: