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Circuit/System Testing

WARNING: This page is about a different car, the 2013 Buick Regal. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, disconnect the KR49 headlamp low beam relay.
  2. Connect a test lamp between the control circuit terminal 85 and B+, ignition ON.
  3. Verify the test lamp turns ON and OFF when commanding the Low Beams ON and OFF with a scan tool.
    • If the test lamp is always OFF 
    1. Ignition OFF, disconnect the X5 harness connector at the K9 body control module, ignition ON.
    2. Test for less than 1 V between the control circuit terminal and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V
    3. Ignition OFF.
    4. Test for less than 2 Ω in the control circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K9 body control module.
    • If the test lamp is always ON 
    1. Ignition OFF, disconnect the X5 harness connector at the K9 body control module.
    2. Test for infinite resistance between the control circuit terminal and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the K9 body control module.
    • If the test lamp turns ON and OFF 
  4. Test or replace the KR49 headlamp low beam relay.
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