Description of the P0775 fault code.
OBD2 Error Codes

P0775 Malfunction of solenoid valve “B” for automatic transmission pressure control

26.05.2022 /

P0775 – OBD-II Trouble Code Technical Description

Trouble code P0775 indicates a malfunction of the transmission pressure control solenoid valve B.

What does trouble code P0775 mean?

Trouble code P0775 indicates a problem with the pressure control solenoid valve “B”, which is located in the automatic transmission. This is a common error code that indicates insufficient fluid pressure in the solenoid valve installed in the automatic transmission. Code P0775 occurs when fluid pressure is insufficient for the solenoid valve in the hydraulic system to operate properly. These valves control gear shifting and control the torque converter. Insufficient fluid pressure leads to malfunctions of the solenoid valves.

Fault code P0775.

Possible reasons

Some possible reasons for the P0775 trouble code:

  • Low or defective transmission fluid.
  • Damaged or worn seals in the transmission hydraulic system.
  • Pressure control solenoid valve “B” is faulty.
  • Incorrect operation or damage to electrical components associated with solenoid valve “B”.
  • Insufficient pressure in the hydraulic system caused by problems with the pump or transmission fluid filter.
  • Damage or blockage of hydraulic passages in the gearbox.
  • Problems with sensors or pressure sensors responsible for monitoring the operating parameters of the gearbox.

These are just some of the possible causes, and the real cause can only be determined after a detailed diagnosis.

What are the symptoms of a fault code? P0775?

Some symptoms that may occur with DTC P0775:

  • Gear shifting problems: The car may struggle or refuse to shift into certain gears, especially at high speeds.
  • Transmission instability: The vehicle may float in engine speed or exhibit unusual changes in transmission characteristics when accelerating or cruising.
  • Lag shifting: There is a delay in gear shifting when you try to shift from one gear to another.
  • Jerky or jerky when shifting gears: The vehicle may jerk into a new gear or jerk when shifting.
  • Increased fuel consumption: An improperly functioning transmission can result in increased fuel consumption due to inefficient gear shifting.
  • Check Engine Light Appears: The P0775 code is usually accompanied by the appearance of a Check Engine Light on the instrument panel.

These symptoms can occur in varying degrees and depending on the specific transmission problem.

How to diagnose a fault code P0775?

To diagnose and resolve DTC P0775, follow these steps:

  1. Checking the automatic transmission fluid: Make sure the transmission fluid level and condition are within the manufacturer's recommendations. Low fluid level or contamination may cause insufficient pressure.
  2. Reading error codes: Use a diagnostic scan tool to read error codes in the engine and transmission control system. This will help identify additional problems with the transmission.
  3. Checking electrical connections: Check all electrical connections, cables and connectors associated with the pressure control solenoid valve “E”. Make sure connections are clean, intact and secure.
  4. Sensor and valve testing: Test the pressure control solenoid valve “E” and associated sensors for proper operation. This may require the use of a multimeter or other specialized tools.
  5. Checking Mechanical Components: Inspect the transmission for physical damage or wear. Pay attention to any fluid leaks or problems with the gear shift mechanisms.
  6. Diagnostics of pressure in the gearbox: Use special tools to measure the pressure in the automatic transmission hydraulic system. Check that the measured pressure matches the manufacturer's recommended values.
  7. Software check: In some cases, the problem may be related to the software of the automatic transmission control module. Check for firmware updates and perform them if necessary.

Once diagnostics have been carried out and the specific cause of the malfunction has been identified, the necessary repairs or replacement of components can begin. If you are unsure of your skills or experience, it is best to have a qualified technician perform the job.

Diagnostic errors

When diagnosing DTC P0775, the following errors may occur:

  • Incorrect Cause Determination: Incorrect interpretation of symptoms or diagnostic results may lead to an incorrect determination of the cause of the P0775 code. For example, symptoms of poor gear shifting can be caused not only by insufficient fluid pressure, but also by other problems in the transmission.
  • Insufficient electrical circuit inspection: The electrical circuit, including wires, connectors, and pressure control solenoid valve, must be thoroughly inspected. Incomplete testing or lack of attention to detail may lead to incorrect conclusions.
  • Inadequate Maintenance: Incorrect maintenance or incorrect transmission settings can also cause P0775. Therefore, it is important to ensure that all transmission maintenance work is carried out correctly and in accordance with the manufacturer's recommendations.
  • Faulty Other Components: Sometimes a fluid pressure problem can be caused by a faulty other component in the transmission system, such as a pump or filter. Incorrect diagnosis can lead to replacement of unnecessary parts and additional costs.
  • Ignoring other error codes: It is important to check for other error codes that may be related to problems with the transmission system. Ignoring additional error codes may result in missing important information about the problem.

How serious is the fault code? P0775?

Trouble code P0775 indicates insufficient fluid pressure at the automatic transmission pressure control solenoid valve. This can lead to improper shifting, loss of power, rough running of the engine and other serious transmission problems.

Insufficient fluid pressure can result in incomplete or delayed solenoid valve activation, which in turn can cause shifting problems and increased wear on internal transmission components.

Therefore, trouble code P0775 should be considered a serious problem that requires immediate attention and diagnosis to prevent further damage to the transmission and ensure the safety and reliability of the vehicle.

What repair will help eliminate the code? P0775?

Resolving trouble code P0775 may require several steps depending on the specific cause of the problem. Below are some possible repair methods:

  1. Checking and replacing transmission fluid: Insufficient or poor quality transmission fluid can result in insufficient pressure in the system. Periodically changing the fluid and adjusting the fluid level to the appropriate level can eliminate this problem.
  2. Replacing the Pressure Control Solenoid Valve: If the problem is a problem with the valve itself, replacement may be necessary. This may require removing the gearbox to access the valve.
  3. Torque Converter Repair or Replacement: If system pressure is unstable due to problems with the torque converter, it may need to be repaired or replaced.
  4. Hydraulic System Inspection and Maintenance: Pressure problems can also occur due to leaks or other defects in the transmission hydraulic system. Checking for leaks and fixing them can help restore normal pressure.

It is recommended that you have a qualified auto mechanic or transmission specialist diagnose and repair the P0775 code problem, as transmission repairs can be complex and require specialized equipment and experience.

How to Diagnose and Fix P0775 Engine Code - OBD II Trouble Code Explain

P0775 – Brand-specific information

Trouble code P0775 can appear on various makes of cars with an automatic transmission, some of them with explanations:

These are just some of the possible car brands that may display this trouble code. For accurate information about the P0775 code on a specific vehicle make, it is recommended that you consult an official service manual or contact your auto repair shop.

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