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Circuit/System Testing

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DTC B2575

  1. Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module, ignition ON.
  2. Verify a test lamp illuminates between the B+ circuit terminal 3 and ground.
    • If the test lamp does not illuminate and the circuit fuse is good 
    1. Ignition OFF, disconnect the X1 harness connector at the X51A Fuse Block - Instrument Panel.
    2. Test for less than 2 Ω in the B+ circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, verify the fuse is not open and there is voltage at the fuse.
    • If the test lamp does not illuminate and the circuit fuse is open 
    1. Ignition OFF, disconnect the X1 harness connector at the X51A Fuse Block - Instrument Panel.
    2. Test for infinite resistance between the B+ circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the X51A Fuse Block - Instrument Panel.
    • If the test lamp illuminates 
  3. Ignition OFF, connect the X1 harness connector at the K9 Body Control Module.
  4. Ignition OFF, exterior lamps OFF, remove the E4G Headlamp - Left Low Beam bulb. It may take up to 2 min for all vehicle systems to power down.
  5. Test for less than 5 Ω between the ground circuit at the socket terminal and ground.
    • If 5 Ω or greater 
    1. Ignition OFF.
    2. Test for less than 2 Ω in the ground circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, repair the open/high resistance in the ground connection.
    • If less than 5 Ω 
  6. Connect a test lamp between the control circuit at the socket terminal and ground, ignition ON.
  7. Verify the test lamp turns ON and OFF when commanding the Left Headlamp Low Beam ON and OFF with a scan tool.
    • If the test lamp is always OFF 
    1. Ignition OFF, disconnect the X4 harness connector at the K9 Body Control Module.
    2. Test for infinite resistance between the control circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance
    3. 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 X4 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, replace the K9 Body Control Module.
    • If the test lamp turns ON and OFF 
  8. Test or replace the E4G Headlamp - Left Low Beam.

DTC B2699

  1. Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module, ignition ON.
  2. Verify a test lamp illuminates between the B+ circuit terminal 2 and ground.
    • If the test lamp does not illuminate and the circuit fuse is good 
    1. Ignition OFF, disconnect the X1 harness connector at the X51A Fuse Block - Instrument Panel.
    2. Test for less than 2 Ω in the B+ circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, verify the fuse is not open and there is voltage at the fuse.
    • If the test lamp does not illuminate and the circuit fuse is open 
    1. Ignition OFF, disconnect the X1 harness connector at the X51A Fuse Block - Instrument Panel.
    2. Test for infinite resistance between the B+ circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the X51A Fuse Block - Instrument Panel.
    • If the test lamp illuminates 
  3. Ignition OFF, connect the X1 harness connector at the K9 Body Control Module.
  4. Ignition OFF, exterior lamps OFF, remove the E4H Headlamp - Right Low Beam bulb. It may take up to 2 min for all vehicle systems to power down.
  5. Test for less than 5 Ω between the ground circuit at the socket terminal and ground.
    • If 5 Ω or greater 
    1. Ignition OFF.
    2. Test for less than 2 Ω in the ground circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, repair the open/high resistance in the ground connection.
    • If less than 5 Ω 
  6. Connect a test lamp between the control circuit at the socket terminal and ground, ignition ON.
  7. Verify the test lamp turns ON and OFF when commanding the Right Headlamp Low Beam ON and OFF with a scan tool.
    • If the test lamp is always OFF 
    1. Ignition OFF, disconnect the X4 harness connector at the K9 Body Control Module.
    2. Test for infinite resistance between the control circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance
    3. 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 X4 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, replace the K9 Body Control Module.
    • If the test lamp turns ON and OFF 
  8. Test or replace the E4H Headlamp - Right Low Beam.
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