WOMS
B code body Medium severity

B1750 Park/Neutral Switch Circuit Open

The OBD2 code B1750 indicates that there is an open circuit in the Park/Neutral switch, which is responsible for detecting whether the transmission is in the park or neutral position

Definition

The OBD2 code B1750 indicates that there is an open circuit in the Park/Neutral switch, which is responsible for detecting whether the transmission is in the park or neutral position

Common causes

  • Faulty park/neutral switch
  • Damaged wiring or connectors
  • Poor electrical connections
  • Malfunctioning transmission control module (TCM)
  • Corroded terminals
  • Blown fuse related to the transmission system
  • Incorrectly adjusted park/neutral switch

Common misdiagnoses

  • Faulty transmission range sensor
  • Defective neutral safety switch
  • Wiring issues or shorts in the harness
  • Malfunctioning engine control module (ECM)
  • Faulty ignition switch
  • Problems with the transmission control module (TCM)
  • Incorrectly installed or damaged transmission components

Troubleshooting steps

  1. 1. Check for Additional Codes

    Use an OBD-II scanner to check for any other related trouble codes. This can provide more context and help identify if there are multiple issues

  2. 2. Inspect the Park/Neutral Switch

    Locate the Park/Neutral switch (also known as the transmission range sensor) and visually inspect it for any signs of damage, corrosion, or loose connections

  3. 3. Ensure that the switch is properly mounted and aligned

  4. 4. Test the Switch

    Use a multimeter to test the continuity of the Park/Neutral switch. Check for proper resistance values according to the vehicle's service manual

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

  6. 6. Check Wiring and Connectors

    Inspect the wiring harness and connectors leading to the Park/Neutral switch for any signs of wear, fraying, or damage

  7. 7. Look for loose or corroded connectors that could cause an open circuit

  8. 8. Examine the Transmission Range Sensor

    If applicable, check the transmission range sensor for proper operation. This sensor is often integrated with the Park/Neutral switch

  9. 9. Test the sensor's output voltage and compare it to the specifications in the service manual

  10. 10. Inspect the ECM/TCM

    Check the engine control module (ECM) or transmission control module (TCM) for any signs of damage or corrosion

  11. 11. Ensure that the ECM/TCM is receiving the correct signals from the Park/Neutral switch

  12. 12. Check Fuses and Relays

    Inspect the relevant fuses and relays associated with the transmission and Park/Neutral switch circuit. Replace any blown fuses

  13. 13. Perform a Visual Inspection of the Transmission

    Ensure that the transmission is properly installed and that there are no mechanical issues that could affect the Park/Neutral switch operation

  14. 14. Clear Codes and Test Drive

    After performing repairs or replacements, clear the trouble codes using the OBD-II scanner

  15. 15. Take the vehicle for a test drive to see if the code reappears

  16. 16. Consult a Professional

    If the issue persists after following these steps, it may be necessary to consult a professional mechanic or technician for further diagnosis. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the B1750 code. Always refer to the specific service manual for your vehicle for detailed procedures and specifications