WOMS
P code powertrain Medium severity

P0852 Park / Neutral Switch Input Circuit High

The OBD2 code P0852 indicates that the Park/Neutral switch input circuit is reading a high voltage signal when it should not, suggesting a potential issue with the switch or its wiring

Definition

The OBD2 code P0852 indicates that the Park/Neutral switch input circuit is reading a high voltage signal when it should not, suggesting a potential issue with the switch or its wiring

Common causes

  • Faulty park/neutral switch
  • Damaged wiring or connectors
  • Short circuit in the circuit
  • Open circuit in the circuit
  • Corroded terminals
  • Faulty transmission control module (TCM)
  • Malfunctioning engine control module (ECM)

Common misdiagnoses

  • Transmission issues
  • Faulty transmission control module (TCM)
  • Defective neutral safety switch
  • Wiring harness problems
  • Faulty engine control module (ECM)
  • Incorrectly installed or damaged shift linkage
  • Battery or charging system issues
  • Faulty sensors related to transmission or engine management

Troubleshooting steps

  1. 1. Check the Vehicle's Manual

    Refer to the vehicle's service manual for specific information about the Park/Neutral switch and its wiring diagram

  2. 2. Visual Inspection

    Inspect the wiring and connectors associated with the Park/Neutral switch for any signs of damage, corrosion, or loose connections

  3. 3. Look for frayed wires, broken connectors, or any signs of wear

  4. 4. Test the Park/Neutral Switch

    Use a multimeter to test the Park/Neutral switch. Check for continuity in the switch when it is in the Park and Neutral positions

  5. 5. If the switch is faulty, it may need to be replaced

  6. 6. Check for Voltage

    With the ignition on (engine off), use a multimeter to check the voltage at the Park/Neutral switch connector

  7. 7. Compare the readings to the specifications in the service manual. If the voltage is higher than expected, there may be a short circuit or a problem with the wiring

  8. 8. Inspect the Transmission Range Sensor

    Some vehicles use a transmission range sensor that works in conjunction with the Park/Neutral switch. Check this sensor for proper operation and wiring integrity

  9. 9. Scan for Additional Codes

    Use an OBD-II scanner to check for any other related trouble codes that may provide additional context for the issue

  10. 10. Check Ground Connections

    Ensure that all ground connections related to the transmission and Park/Neutral switch are clean and secure. Poor grounding can lead to erroneous readings

  11. 11. Inspect the Engine Control Module (ECM)

    In rare cases, the ECM may be malfunctioning. Check for any software updates or known issues with the ECM related to the Park/Neutral switch

  12. 12. Clear the Code and Test Drive

    After performing any repairs or adjustments, clear the trouble code using an OBD-II scanner and take the vehicle for a test drive to see if the code returns

  13. 13. Consult a Professional

    If the issue persists after performing these steps, it may be best to consult a professional mechanic or technician who has experience with your specific vehicle make and model. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the P0852 code