WOMS
B code body Medium severity

B1899 Microphone Input Signal Circuit Open

The OBD2 code B1899 indicates that there is an open circuit in the microphone input signal circuit, which means the system is not receiving a proper signal from the microphone

Definition

The OBD2 code B1899 indicates that there is an open circuit in the microphone input signal circuit, which means the system is not receiving a proper signal from the microphone

Common causes

  • Damaged or frayed wiring
  • Poor electrical connections
  • Faulty microphone
  • Defective audio control module
  • Corroded connectors
  • Short circuit in the circuit
  • Open circuit in the wiring harness
  • Faulty ground connection

Common misdiagnoses

  • Faulty microphone
  • Wiring issues
  • Faulty audio control module
  • Software glitches
  • Poor ground connection
  • Faulty connectors or terminals
  • Issues with the vehicle's infotainment system

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 about the issue

  2. 2. Inspect the Microphone

  3. 3. Locate the microphone in your vehicle (usually near the rearview mirror or in the overhead console)

  4. 4. Check for physical damage or disconnection of the microphone

  5. 5. Examine Wiring and Connectors

  6. 6. Inspect the wiring harness connected to the microphone for any signs of damage, fraying, or corrosion

  7. 7. Ensure that all connectors are securely attached and free of dirt or moisture

  8. 8. Test the Microphone

  9. 9. If possible, test the microphone with a multimeter to ensure it is functioning correctly. Check for continuity and proper resistance

  10. 10. If the microphone is faulty, replace it

  11. 11. Check the Circuit

  12. 12. Use a multimeter to check for continuity in the microphone input signal circuit. Look for any breaks or shorts in the wiring

  13. 13. Verify that the circuit is receiving the correct voltage as specified in the vehicle's service manual

  14. 14. Inspect the Audio System

  15. 15. If the vehicle has an aftermarket audio system, ensure that it is properly installed and compatible with the vehicle's wiring

  16. 16. Check for any loose connections or improper wiring that could affect the microphone circuit

  17. 17. Clear the Codes

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

  18. 18. Consult the Service Manual

    If the issue persists, refer to the vehicle's service manual for specific diagnostic procedures related to the B1899 code and the microphone circuit

  19. 19. Seek Professional Help

    If you are unable to resolve the issue, consider taking the vehicle to a qualified technician or dealership for further diagnosis and repair. By following these steps, you should be able to identify and resolve the issue related to the B1899 code