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Circuit/System Testing

Daytime Running Lamps Malfunction - with T4F

  1. Ignition OFF, exterior lamps OFF, remove the appropriate E4A Park/Daytime Running Lamp bulb. It may take up to 2 min for all vehicle systems to power down.
  2. Test for less than 10Ω between the ground circuit at the socket terminal and ground.
    • If 10Ω or greater 
    1. Ignition OFF.
    2. Test for less than 2Ω in the ground circuit end to end.
      • If 2Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2Ω, repair the open/high resistance in the ground connection.
    • If less than 10Ω 
  3. Connect a test lamp between the control circuit at the socket terminal and ground, ignition ON.
  4. Verify the test lamp turns ON and OFF when commanding the appropriate Front Park Lamp/Daytime Running Lamp 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 2Ω in the control circuit end to end.
      • If 2Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2Ω, 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 1V between the control circuit terminal and ground.
      • If 1V or greater, repair the short to voltage on the circuit.
      • If less than 1V, replace the K9 body Control Module.
    • If the test lamp turns ON and OFF 
  5. Test or replace the E4A Park/Daytime Running Lamp.

Daytime Running Lamps Malfunction - with T4A

  1. Ignition OFF, disconnect the appropriate KR49 Headlamp Low Beam Relay, ignition ON.
  2. Verify a test lamp illuminates between the B+ circuit terminal 86 and ground.
    • If the test lamp does not illuminate 

      Replace the X50A Fuse Block - Underhood.

    • If the test lamp illuminates 
  3. Connect a test lamp between the control circuit terminal 85 and B+, ignition ON.
  4. Verify the test lamp turns ON and OFF when commanding the appropriate Daytime Running Lamp 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 1V between the control circuit terminal and ground.
      • If 1V or greater, repair the short to voltage on the circuit.
      • If less than 1V
    3. Ignition OFF.
    4. Test for less than 2Ω in the control circuit end to end.
      • If 2Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2Ω, 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 
  5. Ignition OFF.
  6. Connect a test lamp between the control circuit terminal 30 and ground, ignition ON.
  7. Verify the test lamp turns ON and OFF when commanding the appropriate Low Beam Lamp 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 terminal and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance
    3. Test for less than 2Ω in the control circuit end to end.
      • If 2Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2Ω, 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 1V between the control circuit terminal and ground.
      • If 1V or greater, repair the short to voltage on the circuit.
      • If less than 1V, replace the K9 body Control Module.
    • If the test lamp turns ON and OFF 
  8. Ignition OFF, exterior lamps OFF, connect the KR49 Headlamp Low Beam Relay.
  9. Remove the appropriate E4 Daytime Running Lamp bulb. It may take up to 2 min for all vehicle systems to power down.
  10. Test for less than 10Ω between the ground circuit at the socket terminal and ground.
    • If 10Ω or greater 
    1. Ignition OFF.
    2. Test for less than 2Ω in the ground circuit end to end.
      • If 2Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2Ω, repair the open/high resistance in the ground connection.
    • If less than 10Ω 
  11. Connect a test lamp between the control circuit at the socket terminal and ground, ignition ON.
  12. Verify the test lamp turns ON and OFF when commanding the appropriate Daytime Running Lamp ON and OFF with a scan tool.
    • If the test lamp is always OFF 
    1. Ignition OFF, disconnect the appropriate KR49 Headlamp Low Beam Relay.
    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 2Ω in the control circuit end to end.
      • If 2Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2Ω, replace the KR49 Headlamp Low Beam Relay.
    • If the test lamp is always ON 
    1. Ignition OFF, disconnect the appropriate KR49 Headlamp Low Beam Relay, ignition ON.
    2. Test for less than 1V between the control circuit terminal and ground.
      • If 1V or greater, repair the short to voltage on the circuit.
      • If less than 1V, replace the KR49 Headlamp Low Beam Relay.
    • If the test lamp turns ON and OFF 
  13. Test or replace the E4 Daytime Running Lamp.

Ambient Light Sensor Malfunction

  1. Ignition OFF, scan tool disconnected, all doors closed, all accessories OFF, open and close drivers door, disconnect the harness connector at the B10B ambient Light/Sunload Sensor. It may take up to 2 min for all vehicle systems to power down.
  2. Test for less than 15Ω between the low reference circuit terminal 6 and ground.
    • If 15Ω or greater 
    1. Ignition OFF, disconnect the X2 harness connector at the K33 HVAC Control Module.
    2. Test for less than 2Ω in the low reference circuit end to end.
      • If 2Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2Ω, replace the K33 HVAC Control Module.
    • If less than 15Ω 
  3. Ignition ON.
  4. Verify the scan tool Ambient Light Sensor parameter is greater than 4.65V.
    • If 4.65V or less 
    1. Ignition OFF, disconnect the X2 harness connector at the K9 body Control Module.
    2. Test for infinite resistance between the signal circuit terminal 5 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 greater than 4.65V 
  5. Install a 3A fused jumper wire between the signal circuit terminal 5 and the low reference circuit terminal 6.
  6. Verify the scan tool Ambient Light Sensor parameter is less than 0.196V.
    • If 0.196V or greater 
    1. Ignition OFF, disconnect the X2 harness connector at the K9 body Control Module, ignition ON.
    2. Test for less than 1V between the signal circuit terminal 5 and ground.
      • If 1V or greater, repair the short to voltage on the circuit.
      • If less than 1V
    3. Test for less than 2Ω in the signal circuit end to end.
      • If 2Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2Ω, replace the K9 body Control Module.
    • If less than 0.196V 
  7. Test or replace the B10B ambient Light/Sunload Sensor
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