WOMS
C code chassis Medium severity

C1860 PRNDL Input #3 Circuit Failure

The OBD2 code C1860 PRNDL Input #3 Circuit Failure indicates a malfunction in the circuit related to the transmission range sensor, specifically the input signal for the third position of the gear selector

Definition

The OBD2 code C1860 PRNDL Input #3 Circuit Failure indicates a malfunction in the circuit related to the transmission range sensor, specifically the input signal for the third position of the gear selector

Common causes

  • Faulty PRNDL switch
  • Wiring issues (shorts or open circuits)
  • Poor connections or corroded terminals
  • Malfunctioning transmission control module (TCM)
  • Faulty vehicle speed sensor
  • Issues with the powertrain control module (PCM)
  • Grounding problems
  • Damaged harness or connectors

Common misdiagnoses

  • Transmission Control Module (TCM) failure
  • Faulty PRNDL switch
  • Wiring issues or shorts in the circuit
  • Malfunctioning gear selector
  • Defective engine control module (ECM)
  • Incorrectly calibrated transmission
  • Faulty speed sensor
  • Issues with the vehicle's body control module (BCM)
  • Problems with the ignition switch
  • Low transmission fluid levels

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 Wiring and Connectors

    Visually inspect the wiring and connectors associated with the PRNDL switch and the transmission range sensor. Look for

  3. 3. Damaged, frayed, or corroded wires

  4. 4. Loose or corroded connectors

  5. 5. Signs of wear or heat damage

  6. 6. Test the PRNDL Switch

    The PRNDL switch (or transmission range sensor) is responsible for sending the position of the gear selector to the vehicle's computer. Test the switch for proper operation

  7. 7. Use a multimeter to check for continuity and resistance values according to the manufacturer's specifications

  8. 8. Ensure that the switch is correctly aligned and mounted

  9. 9. Check for Ground Issues

    Ensure that the ground connections for the PRNDL switch and related circuits are secure and free of corrosion. Poor grounding can lead to circuit failures

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

    If the PRNDL switch and wiring are functioning correctly, the issue may lie within the TCM. Check for

  11. 11. Software updates or reprogramming needs

  12. 12. Faulty TCM that may require replacement

  13. 13. Perform a Visual Inspection of the Transmission

    Inspect the transmission for any signs of damage or leaks that could affect the operation of the PRNDL switch

  14. 14. Clear Codes and Test Drive

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

  15. 15. Seek Professional Help

    If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or technician who has experience with transmission systems and OBD-II diagnostics. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the C1860 code