WOMS
B code body Medium severity

B1471 Lamp Headlamp Input Circuit Open

The OBD2 code B1471 indicates that there is an open circuit in the headlamp input circuit, meaning the vehicle's system is not detecting a proper signal from the headlamp switch or related components

Definition

The OBD2 code B1471 indicates that there is an open circuit in the headlamp input circuit, meaning the vehicle's system is not detecting a proper signal from the headlamp switch or related components

Common causes

  • Open circuit in the headlamp wiring
  • Faulty headlamp switch
  • Defective headlamp relay
  • Bad ground connection
  • Damaged or corroded connectors
  • Faulty headlamp assembly
  • Issues with the body control module (BCM)

Common misdiagnoses

  • Faulty headlight bulb
  • Bad headlight relay
  • Damaged wiring or connectors
  • Faulty body control module (BCM)
  • Incorrectly installed headlight assembly
  • Malfunctioning switch or control stalk
  • Grounding issues
  • Corroded terminals or connectors

Troubleshooting steps

  1. 1. Visual Inspection

    Check Wiring and Connectors: Inspect the wiring harness and connectors related to the headlamp circuit for any signs of damage, corrosion, or loose connections

  2. 2. Look for Shorts or Breaks

    Look for any frayed wires or broken connections that could cause an open circuit

  3. 3. Check the Headlamp Bulbs

    Inspect Bulbs: Ensure that the headlamp bulbs are functioning properly. Replace any burnt-out bulbs

  4. 4. Test Bulb Sockets

    Check the bulb sockets for corrosion or damage

  5. 5. Test the Headlamp Switch

    Functionality Check: Ensure that the headlamp switch is functioning correctly. If the switch is faulty, it may not send the proper signal to the BCM

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

    Scan for Additional Codes: Use an OBD-II scanner to check for any other related trouble codes that may provide more context

  7. 7. Inspect BCM Connections

    Ensure that the BCM connectors are secure and free of corrosion

  8. 8. Perform Continuity Tests

    Test Wiring: Use a multimeter to perform continuity tests on the wiring between the headlamp and the BCM. Look for any breaks in the circuit

  9. 9. Check Ground Connections

    Ensure that the ground connections for the headlamp circuit are secure and functioning

  10. 10. Check Fuses

    Inspect Fuses: Check the fuses related to the headlamp circuit. Replace any blown fuses

  11. 11. Test the Relay (if applicable)

    Check Relay Operation: If the vehicle uses a relay for the headlamp circuit, test the relay to ensure it is functioning properly

  12. 12. Clear Codes and Test Drive

    Clear the Code: After performing repairs, clear the trouble code using an OBD-II scanner

  13. 13. Test Drive

    Take the vehicle for a test drive to see if the code returns

  14. 14. Consult Repair Manual

    Refer to Vehicle-Specific Information: If the issue persists, consult the vehicle's repair manual for specific diagnostic procedures related to the headlamp circuit

  15. 15. Seek Professional Help

    Contact a Mechanic: If you are unable to resolve the issue, it may be best to consult a professional mechanic for further diagnosis and repair. By following these steps, you should be able to identify and resolve the issue causing the B1471 code. Always ensure safety precautions are taken when working on electrical systems in vehicles