WOMS
P code powertrain Medium severity

P0938 Hydraulic Oil Temperature Sensor Range/Performance

The OBD2 code P0938 indicates that the hydraulic oil temperature sensor is reporting a temperature reading that is outside the expected range or is performing incorrectly, which may affect the operation of the...

Definition

The OBD2 code P0938 indicates that the hydraulic oil temperature sensor is reporting a temperature reading that is outside the expected range or is performing incorrectly, which may affect the operation of the transmission or hydraulic system

Common causes

  • Faulty hydraulic oil temperature sensor
  • Wiring issues (shorts, opens, or corrosion)
  • Poor electrical connections
  • Faulty engine control module (ECM)
  • Low hydraulic fluid levels
  • Contaminated hydraulic fluid
  • Malfunctioning hydraulic system components

Common misdiagnoses

  • Transmission fluid issues
  • Faulty transmission control module (TCM)
  • Wiring or connector problems
  • Faulty hydraulic oil temperature sensor
  • Engine coolant temperature sensor issues
  • Transmission overheating
  • Incorrect transmission fluid type or level
  • Faulty engine control module (ECM)

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 help identify if there are related issues that need to be addressed

  2. 2. Inspect the Wiring and Connectors

    Visually inspect the wiring and connectors associated with the hydraulic oil temperature sensor. Look for signs of damage, corrosion, or loose connections

  3. 3. Ensure that the connectors are securely attached and that there are no broken wires

  4. 4. Test the Hydraulic Oil Temperature Sensor

    Use a multimeter to test the resistance of the hydraulic oil temperature sensor. Compare the readings to the specifications provided in the vehicle's service manual

  5. 5. If the sensor is out of range, it may need to be replaced

  6. 6. Check the Hydraulic Fluid Level and Condition

    Ensure that the hydraulic fluid is at the correct level and is in good condition. Contaminated or low fluid can affect sensor readings

  7. 7. If the fluid is dirty or burnt, consider flushing and replacing it

  8. 8. Inspect the Transmission Control Module (TCM)

    Check for any issues with the TCM, as it processes the signals from the hydraulic oil temperature sensor. Ensure that the TCM is functioning correctly and that there are no software issues

  9. 9. Look for Leaks or Blockages

    Inspect the hydraulic system for any leaks or blockages that could affect the temperature readings. Ensure that the hydraulic lines are clear and functioning properly

  10. 10. Perform a System Reset

    After addressing any issues found, clear the trouble codes using the OBD-II scanner and take the vehicle for a test drive to see if the code returns

  11. 11. Consult Technical Service Bulletins (TSBs)

    Check for any TSBs related to the P0938 code for your specific vehicle make and model. Manufacturers may have issued guidance or fixes for known issues

  12. 12. Seek Professional Help

    If the problem persists after performing the above steps, it may be necessary to consult a professional mechanic or technician who has experience with your vehicle's specific system. By following these troubleshooting steps, you can identify and potentially resolve the issue associated with the P0938 code