Engine-CodesBuick – P0742 Buick

P0742 Buick Code - Torque Converter Clutch System Stuck On Or Transmission Hydraulic/Mechanical Performance

Quick Answer

The P0742 diagnostic trouble code (DTC) for Buick vehicles indicates an issue with the Torque Converter Clutch (TCC) system being stuck on or a problem with the transmission's hydraulic or mechanical performance. Common causes include Malfunctioning TCC solenoid, Faulty torque converter, Low transmission fluid levels. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means
P0742 Buick indicates Torque Converter Clutch System Stuck On Or Transmission Hydraulic/Mechanical Performance.
Common causes
Common causes include Malfunctioning TCC solenoid, Faulty torque converter, Low transmission fluid levels.
Severity
High - diagnose this code as soon as possible.
Can I drive?
Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Table of contents Created and updated by William Orellana on Sep 12, 2024
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Code P0742 Buick Description

The P0742 diagnostic trouble code (DTC) for Buick vehicles indicates an issue with the Torque Converter Clutch (TCC) system being stuck on or a problem with the transmission's hydraulic or mechanical performance. The torque converter is a critical component of an automatic transmission system that allows the engine to run even when the vehicle is stationary by transmitting power from the engine to the transmission. The TCC system is responsible for engaging and disengaging the clutch in the torque converter to improve fuel efficiency and reduce slippage.

OBDII Code P0742 Buick - Torque Converter Clutch System Stuck On Or Transmission Hydraulic/Mechanical Performance
P0742 Buick Code - Torque Converter Clutch System Stuck On Or Transmission Hydraulic/Mechanical Performance

Common Causes of P0742 Buick

  1. Malfunctioning TCC solenoid
  2. Faulty torque converter
  3. Low transmission fluid levels
  4. Clogged transmission filter
  5. Internal transmission damage

Symptoms of P0742 Buick

  1. Poor fuel economy
  2. Harsh shifting
  3. Engine stalling at idle
  4. Transmission overheating
  5. Reduced driving comfort

How to Fix P0742 Buick

  1. Diagnose the specific cause of the issue by performing a thorough inspection of the TCC system and transmission components.
  2. Replace the TCC solenoid if it is found to be faulty, ensuring proper installation and calibration.
  3. Inspect and potentially replace the torque converter if it is damaged or malfunctioning.
  4. Check and refill transmission fluid to the recommended level, ensuring it is clean and free of debris.
  5. Replace the transmission filter if it is clogged or dirty, ensuring proper filtration of the fluid.

Cost to Fix P0742 Buick

The typical repair costs for addressing a P0742 Buick code can vary depending on the specific cause of the issue and the extent of the repairs needed. In general, the cost of parts such as a TCC solenoid or torque converter can range from $100 to $500, while the labor costs for the repair process can range from $200 to $800. Overall, the total repair costs for this issue can range from $300 to $1300. It is advisable to consult with a qualified mechanic or auto repair shop for a more accurate estimate based on the specific circumstances of the vehicle. Keep in mind that factors such as location, vehicle make and model, and engine type can influence the final repair costs.

Tech Notes for P0742 Buick

When a transmission solenoid is stuck on, in most cases the problem is not the electrical part of the solenoid; the problem is foreign material obstructing the mechanical function of the solenoid or the flow of the fluid through the transmission valve body. If the transmission fluid is very dirty, it is recommended to change the transmission fluid and if possible, remove the transmission pan for further diagnosis. Excessive debris or metal particles on the transmission pan could be an indication that there is a transmission mechanical failure, and that the transmission will need to be rebuilt or replaced.



There is a factory service bulletin for the following Buick Models:

2001-2005 Buick LeSabre

2001-2005 Buick Park Avenue

2002-2007 Buick Rendezvous

2002-2007 Buick Rendezvous AWD

2005-2007 Buick Terraza

2005-2007 Buick Terraza EXT

2005-2007 Buick Terraza 4WD

2005-2008 Buick Allure (Canada Only)

2005-2008 Buick LaCrosse

2006-2008 Buick Lucerne

Buick Factory Service Bulletin OBDII Code P0742

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0742 Buick Code

1. What are the common symptoms of OBDII code P0742 in a Buick related to the Torque Converter Clutch System?

The common symptoms include harsh shifting, decreased fuel efficiency, and the vehicle feeling like it's struggling to accelerate.

2. What are the possible causes of OBDII code P0742 in a Buick indicating Torque Converter Clutch System Stuck On or Transmission Hydraulic/Mechanical Performance issues?

Possible causes may include a faulty torque converter clutch solenoid, low transmission fluid levels, a malfunctioning torque converter, or internal transmission damage.

3. How can I diagnose OBDII code P0742 in my Buick if the Torque Converter Clutch System is stuck on or there are transmission performance issues?

Diagnosis involves using a scan tool to read the code, checking transmission fluid levels and condition, inspecting the torque converter clutch solenoid, and performing a thorough transmission system inspection.

4. What are the repair options for resolving OBDII code P0742 in a Buick related to the Torque Converter Clutch System?

Repair options may include replacing the torque converter clutch solenoid, addressing any transmission fluid leaks, repairing or replacing the torque converter, or conducting a full transmission rebuild if necessary.

5. Can driving with OBDII code P0742 in a Buick cause further damage to the vehicle?

Continuing to drive with this code may lead to increased wear on the transmission components, reduced fuel efficiency, and potential loss of power over time. It is recommended to address the issue promptly.

6. Are there any DIY tips for addressing OBDII code P0742 in a Buick at home?

While some basic checks like inspecting transmission fluid levels can be done at home, diagnosing and repairing the specific issue causing the code typically requires professional knowledge and tools. It's advisable to consult a qualified mechanic.

7. How much does it cost to repair OBDII code P0742 in a Buick at a dealership or repair shop?

The cost of repairing this code can vary depending on the specific cause, parts needed, and labor costs. It's recommended to obtain multiple quotes from reputable repair shops to compare prices.

8. Is OBDII code P0742 in a Buick a common issue, and are there any recalls related to this problem?

While the code may occur in some Buick vehicles, it is not necessarily a widespread issue. It's advisable to check with Buick or the National Highway Traffic Safety Administration (NHTSA) for any related recalls.

9. Can resetting the OBDII code P0742 in a Buick fix the issue temporarily?

Resetting the code may temporarily turn off the check engine light, but it will not address the underlying problem causing the code. It's crucial to diagnose and repair the issue to prevent further damage.

10. How long does it typically take to repair OBDII code P0742 in a Buick at a professional repair shop?

The repair time can vary depending on the complexity of the issue, availability of parts, and the shop's workload. In some cases, it may take a few hours to a full day to diagnose and repair the problem.

Discuss the causes and fixes for P0742 Buick OBDII Code

  • The check engine soon light turn on after I run the drive cycle on my 2002 Buick Rendezvous cx the code say that the torque convert stuck on