The P0779 trouble code indicates an intermittent electrical issue with the pressure control solenoid “B” in the transmission control system. This solenoid is responsible for regulating hydraulic pressure within the transmission, which is crucial for proper gear shifting.
Pressure Control Solenoid “B” Intermittent
Code symptoms P0779.
1. Illumination of the Check Engine Light (CEL) on the dashboard.
2. Intermittent transmission shifting issues, such as harsh or delayed shifting, or failure to shift at all.
3. Vehicle may go into limp mode intermittently to prevent further damage.
4. Intermittent decrease in fuel efficiency due to improper transmission shifting.
This code is common in brands such as:: Chevrolet, Renault, Ford, Toyota, Nissan, Mercedes Benz, Honda.
Causes of the code P0779.
1. Intermittent fault within the pressure control solenoid “B”.
2. Intermittent wiring harness or connector issues, such as corrosion, damage, or poor connection.
3. Intermittent low transmission fluid level or contaminated fluid.
4. Intermittent internal transmission problems, such as valve body issues or mechanical failures.
Code Solutions P0779.
1. Begin by using a scan tool to clear the trouble codes and monitor the transmission’s behavior during a test drive. Note any shifting patterns or symptoms.
2. Perform a thorough visual inspection of the wiring harness and connectors associated with pressure control solenoid “B” for signs of intermittent damage, corrosion, or loose connections. Repair or replace any intermittently damaged wiring or connectors as needed.
3. Use a multimeter to perform voltage and continuity tests on the pressure control solenoid “B” and related circuits during key-on and engine running conditions. Pay special attention to intermittent voltage drops or fluctuations that could indicate an intermittent issue.
4. Consider performing intermittent transmission fluid level and condition checks. Intermittent low fluid level or contaminated fluid can affect solenoid operation intermittently. If necessary, perform a transmission fluid flush and refill with the manufacturer’s recommended fluid.
5. If the issue persists intermittently, further diagnosis may be needed to inspect the internal components of the transmission intermittently, such as the valve body or pressure control circuits. This may require the expertise of a qualified mechanic or transmission specialist and specialized intermittent diagnostic equipment.