WOMS
P code powertrain Medium severity

P0799 Pressure Control Solenoid C Intermittent

The OBD2 code P0799 indicates an intermittent issue with the pressure control solenoid C, which is responsible for regulating transmission fluid pressure in the vehicle's transmission system

Definition

The OBD2 code P0799 indicates an intermittent issue with the pressure control solenoid C, which is responsible for regulating transmission fluid pressure in the vehicle's transmission system

Common causes

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

Common misdiagnoses

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

Troubleshooting steps

  1. 1. Check for Additional Codes

    Use an OBD-II scanner to check for any other trouble codes that may be present. Sometimes, multiple codes can provide more context for the issue

  2. 2. Inspect Wiring and Connectors

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

  3. 3. Test the Solenoid

    If accessible, test the pressure control solenoid C for proper operation. This may involve checking the resistance of the solenoid with a multimeter or applying voltage to see if it activates correctly

  4. 4. Check Transmission Fluid

    Ensure that the transmission fluid is at the correct level and in good condition. Low or dirty fluid can affect solenoid operation. If the fluid is contaminated, consider a transmission fluid change

  5. 5. Inspect Transmission Control Module (TCM)

    The TCM controls the operation of the solenoids. Check for any issues with the TCM, including software updates or faults that may need to be addressed

  6. 6. Look for Mechanical Issues

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

  7. 7. Perform a Voltage and Ground Test

    Check the voltage and ground supply to the solenoid while the vehicle is running. Ensure that the solenoid is receiving the correct voltage and that the ground is solid

  8. 8. Check for Fluid Leaks

    Inspect the transmission for any fluid leaks that could affect pressure and solenoid operation

  9. 9. Clear Codes and Test Drive

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

  10. 10. Consult Repair Manual

    Refer to the vehicle's service manual for specific diagnostic procedures and specifications related to the pressure control solenoid and transmission system. 1

  11. 11. Seek Professional Help

    If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or transmission specialist for further diagnosis and repair. By following these steps, you can systematically identify and address the underlying cause of the P0799 code