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P code powertrain High severity

P0779 Pressure Control Solenoid B Intermittent

The OBD2 code P0779 indicates a malfunction in the pressure control solenoid B, which is responsible for regulating transmission fluid pressure.

Definition

The OBD2 code P0779 indicates a malfunction in the pressure control solenoid B, which is responsible for regulating transmission fluid pressure. The "intermittent" aspect means that the issue is not constant and may occur sporadically

Common causes

  • Faulty pressure control solenoid B
  • Wiring issues or damaged connectors
  • Low transmission fluid level
  • Contaminated transmission fluid
  • Faulty transmission control module (TCM)
  • Internal transmission problems
  • Poor electrical connections
  • Faulty valve body

Common misdiagnoses

  • Transmission fluid issues
  • Faulty transmission control module (TCM)
  • Wiring or connector problems
  • Other solenoid failures
  • Torque converter issues
  • Valve body problems
  • Transmission overheating
  • Mechanical transmission failures

Troubleshooting steps

  1. 1. Check for Additional Codes

    Use an OBD-II scanner to check for any other trouble codes that may be present. This can provide more context and help identify related issues

  2. 2. Inspect Wiring and Connectors

    Examine the wiring and connectors associated with the pressure control solenoid B. Look for signs of damage, corrosion, or loose connections that could cause intermittent issues

  3. 3. Test the Pressure Control Solenoid

    Use a multimeter to test the resistance of the solenoid. Compare the readings to the specifications provided in the vehicle's service manual. If the resistance is outside the specified range, the solenoid may need to be replaced

  4. 4. Check Transmission Fluid Level and Condition

    Low or dirty transmission fluid can cause shifting issues and affect solenoid performance. Ensure the fluid is at the correct level and in good condition. If the fluid is dirty or burnt, consider a transmission fluid change

  5. 5. Inspect the Transmission Filter

    A clogged transmission filter can restrict fluid flow and affect solenoid operation. If the filter is dirty, replace it

  6. 6. Check for Mechanical Issues

    Inspect the transmission for any mechanical problems that could affect solenoid operation, such as sticking valves or internal wear

  7. 7. Test the Transmission Control Module (TCM)

    If the solenoid and wiring are in good condition, the issue may lie with the TCM. Testing or reprogramming the TCM may be necessary

  8. 8. Clear Codes and Test Drive

    After performing any repairs or replacements, clear the trouble codes and take the vehicle for a test drive to see if the code returns

  9. 9. Consult a Professional

    If the issue persists after performing these steps, it may be best to consult a professional mechanic or transmission specialist for further diagnosis. Always refer to the specific service manual for your vehicle for detailed procedures and specifications, as they can vary by make and model