WOMS
B code body Medium severity

B1693 Autolamp On Circuit Failure

The OBD2 code B1693 indicates a failure in the autolamp on circuit, which typically means there is a malfunction in the system that controls the automatic headlights

Definition

The OBD2 code B1693 indicates a failure in the autolamp on circuit, which typically means there is a malfunction in the system that controls the automatic headlights

Common causes

  • Faulty autolamp sensor
  • Damaged wiring or connectors
  • Short circuit in the autolamp circuit
  • Failed body control module (BCM)
  • Malfunctioning headlight switch
  • Corroded or loose electrical connections
  • Faulty relay for the autolamp system

Common misdiagnoses

  • Faulty headlight switch
  • Bad body control module (BCM)
  • Wiring issues or shorts in the circuit
  • Defective autolamp sensor
  • Malfunctioning daytime running lights (DRL) module
  • Incorrectly programmed BCM
  • Issues with the vehicle's lighting control system

Troubleshooting steps

  1. 1. Check the Owner's Manual

    Refer to the vehicle's owner's manual for specific information about the autolamp system and any related fuses or relays

  2. 2. Inspect Fuses

    Check the fuses related to the autolamp system. A blown fuse can cause the system to fail. Replace any blown fuses and see if the code clears

  3. 3. Examine Wiring and Connectors

    Inspect the wiring and connectors associated with the autolamp system for any signs of damage, corrosion, or loose connections. Pay special attention to the wiring harness leading to the headlight switch and the body control module (BCM)

  4. 4. Test the Headlight Switch

    The headlight switch may be faulty. Use a multimeter to test the switch for continuity and proper operation. If the switch is defective, it may need to be replaced

  5. 5. Check the Body Control Module (BCM)

    The BCM controls the autolamp feature. If there are issues with the BCM, it may need to be reprogrammed or replaced. Check for any software updates or recalls related to the BCM

  6. 6. Inspect the Autolamp Sensor

    Some vehicles have a light sensor that detects ambient light levels. If this sensor is malfunctioning, it may prevent the autolamp feature from working. Test the sensor and replace it if necessary

  7. 7. Scan for Additional Codes

    Use an OBD-II scanner to check for any additional trouble codes that may provide more context for the issue. Address any other codes that may be present

  8. 8. Clear the Code

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

  9. 9. 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 B1693 code