P0774 Shift Solenoid Valve "E" Circuit Intermittent / Erratic

P0774 – OBD-II Trouble Code Technical Description

Trouble code P0774 indicates that the PCM has detected an intermittent/intermittent signal from the shift solenoid valve "E" circuit.

What does the fault code mean P0774?

Trouble code P0774 indicates that the automatic transmission control module (PCM) has detected an intermittent or erratic signal from the shift solenoid valve “E” circuit. Other error codes related to the shift solenoid valves may also appear along with this code.

Trouble code P0774 is a common trouble code for vehicles with a computer-controlled automatic transmission. Shift solenoid valves are used to control fluid levels in various hydraulic circuits and to regulate or change gear ratios. This is necessary for the proper operation of the vehicle, as well as for the vehicle to be able to reduce or increase speed and use fuel efficiently.

Possible reasons

Some possible reasons for the P0774 trouble code:

• Damaged or corroded wiring in the electrical circuit of the solenoid valve “E”.
• Open or short circuit in the electrical circuit.
• Incorrect connection or faulty connector in the electrical circuit.
• The solenoid valve “E” itself is faulty.
• Problems with the automatic transmission control module (PCM).
• Overheating or overload of the vehicle's electrical system.

What are the symptoms of a fault code? P0774?

Symptoms when trouble code P0774 is present may include the following:

• Shifting Problems: The vehicle may have difficulty shifting gears or may not shift smoothly.
• Unusual noises from the transmission: There may be a noise or knocking sound when shifting gears, indicating a problem with the transmission.
• Increased fuel consumption: Inefficient transmission operation can lead to increased fuel consumption due to incorrect gear shifts.
• Check Engine Light: Lights up on your vehicle's dashboard to indicate there is a problem with the transmission system.

How to diagnose a fault code P0774?

The following steps are recommended to diagnose DTC P0774:

1. Checking Error Codes: Use a diagnostic scan tool to read all error codes from the engine and transmission control system. Check to see if there are other related error codes that may help narrow your search.
2. Checking the transmission fluid level: Make sure the transmission fluid level is within the recommended range. Low fluid levels can cause the transmission to malfunction.
3. Checking the condition of the transmission fluid: Assess the condition of the transmission fluid for contamination, impurities or signs of oxidation. Replacing dirty or contaminated fluid can correct some transmission problems.
4. Checking electrical connections: Check the electrical connections and wiring associated with the shift solenoid valve “E” for damage, corrosion or breaks. Make sure all connections are tight and secure.
5. Checking the solenoid valve: Evaluate the operation of solenoid valve “E” using specialized equipment or a multimeter. Verify that the valve is functioning properly and responding to commands from the control module.
6. Checking the transmission control module: In some cases, the problem may be due to a faulty transmission control module (TCM). Perform additional diagnostics to verify TCM functionality.
7. Checking Mechanical Components: Use a specialized tool to inspect mechanical transmission components such as solenoids, valves, and shift mechanisms for wear, damage, or locking.
8. Professional diagnostics: If you are not confident in your skills or do not have the necessary equipment, it is recommended that you contact a qualified auto mechanic or auto repair shop for more in-depth diagnostics and repairs.

Diagnostic errors

When diagnosing DTC P0774, the following errors may occur:

• Incorrect interpretation of code: Some mechanics may mistakenly identify the cause of the P0774 code as a problem with the solenoid valve itself, without considering other possible causes such as problems with the electrical circuit or control module.
• Insufficient electrical circuit check: Misdiagnosis can occur if the mechanic does not sufficiently inspect the electrical circuit, including the wires, connectors, and connections associated with the solenoid valve.
• Incorrect assessment of the condition of the transmission fluid: If a mechanic does not pay proper attention to the condition of the transmission fluid or does not check for levels and condition, it may result in an incorrect diagnosis.
• Incorrect component replacement: Sometimes a mechanic may assume that the problem is caused by a faulty solenoid valve and replace it without a thorough diagnosis, which can result in additional costs and an unresolved problem.
• Ignoring other error codes: If there are other related error codes such as P0770, P0771, P0772 и P0773, ignoring them when diagnosing P0774 may result in missing additional problems in the transmission system.

To avoid these errors, it is important to carry out a thorough and systematic diagnosis, taking into account all possible causes and factors that may affect the operation of the transmission system.

How serious is the fault code? P0774?

Trouble code P0774 indicates a problem with the automatic transmission's shift solenoid valve "E" circuit. This problem can affect the proper functioning of the transmission, which can result in improper shifting, loss of power, poor fuel economy, and other vehicle performance problems. While some symptoms may be mild, a faulty transmission can create dangerous driving conditions and lead to serious accidents. Therefore, code P0774 should be considered serious and requires immediate attention.

What repair will help eliminate the code? P0774?

Troubleshooting trouble code P0774 may include the following steps:

1. Electrical Circuit Check: First check the "E" solenoid valve electrical circuit for opens, shorts, or damaged wiring. If damage is found, it must be repaired or replaced.
2. Solenoid Valve Check: Solenoid valve “E” may be faulty or stuck. Check its functionality and, if necessary, replace the valve.
3. Engine Control Module (PCM) Check: In some cases, the problem may be due to a faulty PCM. Check it for errors and malfunctions; the PCM may need to be repaired or replaced.
4. Software Update: Sometimes problems with error codes can be caused by outdated software in the PCM. Check for software updates and perform them if necessary.
5. Check other components: In some cases, the problem may be related to other components of the transmission control system. Check the condition of other sensors, valves and connections that may affect transmission operation.

It is recommended to carry out diagnostics using professional equipment and contact a qualified auto mechanic to perform repair work.

How to Diagnose and Fix P0774 Engine Code - OBD II Trouble Code Explain

P0774 – Brand-specific information

The specific causes and solutions for trouble code P0774 may vary depending on the manufacturer and model of the vehicle, some well-known car brands and their meanings for this code:

• Toyota / Lexus: P0774 means “Shift Solenoid Valve “E” Intermittent Signal.”
• Ford: P0774 typically indicates “Shift Solenoid “E” Intermittent.”
• Honda/Acura: Shift solenoid valve “E” Intermittent signal.
• Chevrolet / GMC (General Motors): Shift solenoid "E" Intermittent signal.
• Nissan/Infiniti: P0774 may indicate a problem with “Solenoid valve 'E' - Intermittent signal.”

This is general information only, and the specifics of the code may vary depending on the specific model and year of the vehicle. It is recommended that you consult your service manual or a qualified automotive repair technician to determine the exact cause and repair.