WOMS
C code chassis High severity

C1499 Transfer Case Contact Plate "A" Encoder Circuit Failure

The OBD2 code C1499 indicates a failure in the encoder circuit of the transfer case contact plate "A," which typically affects the transfer case's ability to accurately determine its position or mode

Definition

The OBD2 code C1499 indicates a failure in the encoder circuit of the transfer case contact plate "A," which typically affects the transfer case's ability to accurately determine its position or mode

Common causes

  • Faulty transfer case contact plate
  • Damaged or corroded wiring or connectors
  • Short circuit in the encoder circuit
  • Open circuit in the encoder circuit
  • Failed encoder sensor
  • Poor ground connection
  • Moisture or contamination in the connector or circuit

Common misdiagnoses

  • Transfer case motor failure
  • Transfer case assembly failure
  • Wiring harness issues
  • Faulty encoder sensor
  • Control module failure
  • Low transmission fluid levels
  • Incorrect transfer case fluid
  • Battery or electrical system issues
  • Faulty switches or relays
  • Software or calibration issues

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 other issues affecting the transfer case

  2. 2. Inspect the Wiring and Connectors

    Visually inspect the wiring harness and connectors associated with the transfer case encoder. Look for

  3. 3. Damaged, frayed, or corroded wires

  4. 4. Loose or disconnected connectors

  5. 5. Signs of moisture or dirt ingress

  6. 6. Test the Encoder Circuit

    Use a multimeter to test the voltage and resistance in the encoder circuit. Check for

  7. 7. Proper voltage supply to the encoder

  8. 8. Ground continuity

  9. 9. Resistance values that fall within the manufacturer’s specifications

  10. 10. Check the Transfer Case Control Module

    Inspect the transfer case control module for any signs of damage or corrosion. If possible, test the module to ensure it is functioning correctly

  11. 11. Examine the Transfer Case Contact Plate

    The contact plate itself may be faulty. Inspect it for

  12. 12. Physical damage

  13. 13. Wear or contamination that could affect its operation

  14. 14. Perform a Functional Test

    If the vehicle allows, perform a functional test of the transfer case operation. Engage and disengage different modes (e.g., 2WD, 4WD) to see if the encoder responds correctly

  15. 15. Clear Codes and Test Drive

    After performing any repairs or adjustments, clear the trouble codes using the OBD-II scanner. Take the vehicle for a test drive to see if the code reappears

  16. 16. Consult Technical Service Bulletins (TSBs)

    Check for any TSBs related to the specific make and model of the vehicle. Manufacturers may have issued guidance on common issues or fixes for the C1499 code

  17. 17. Seek Professional Help

    If the issue persists after performing the above steps, it may be necessary to consult a professional mechanic or technician who has experience with transfer case systems and can perform more advanced diagnostics

  18. 18. Consider Replacement Parts

    If all else fails, consider replacing the transfer case encoder or the contact plate if it is determined to be faulty.Conclusion Always refer to the vehicle’s service manual for specific diagnostic procedures and specifications related to the transfer case and encoder circuit. Each vehicle may have unique characteristics that could affect troubleshooting steps