LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2012 >> Traverse LTZ, FWD >> Repair and Diagnosis >> Accessories & Equipment >> Headlights >> Lighting System >> Diagnostic Information and Procedures >> DTC B257A >> Circuit/System Testing

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the headlamp switch.
  2. Verify that a test lamp illuminates between the ground circuit terminal 8 and B+.
    • If the test lamp does not illuminate, test the ground circuit for an open/high resistance.
  3. Ignition ON, verify the scan tool Auto Hdlp. Disable Sw. parameter is Inactive.
    • If not the specified value, test the signal circuit terminal 3 for a short to ground. If the circuit tests normal, replace the BCM.
  4. Verify the scan tool Headlamp Switch parameter is Inactive.
    • If not the specified value, test the signal circuit terminal 1 for a short to ground. If the circuit tests normal, replace the BCM.
  5. Verify the scan tool Parklamp Switch parameter is Inactive.
    • If not the specified value, test the signal circuit terminal 2 for a short to ground. If the circuit tests normal, replace the BCM.
  6. If all circuits test normal, test or replace the headlamp switch.
scientia non olet · About LEMON Manuals