FixVault

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the appropriate B51 headlamp leveling sensor.
  2. Test for less than 5 Ω between the low reference circuit terminal 3 and ground.
  3. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K28 headlamp leveling control module.
  4. Ignition ON, test for 4.8-5.2 V between the 5V reference circuit terminal 1 and ground.
  5. If less than the specified range, test the 5V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K28 headlamp leveling control module.
  6. If greater than the specified range, test the 5V reference circuit for a short to voltage. If the circuit tests normal, replace the K28 headlamp leveling control module.
  7. Verify the appropriate scan tool Leveling Position Sensor parameter is 0 V.
  8. If greater than the specified range, test the signal circuit pin 2 for a short to voltage. If the circuit tests normal, replace the K28 headlamp leveling control module.
  9. Install a 3 A fused jumper wire between the signal circuit terminal 2 and the 5V reference circuit terminal 1. Verify the appropriate scan tool Leveling Position Sensor parameter is greater than 5 V.
  10. If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K28 headlamp leveling control module.
  11. If all circuits test normal, replace the B51 headlamp leveling sensor.