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Circuit/System Testing

Brake Pedal Position Sensor Malfunction

  1. Ignition OFF, disconnect the harness connector at the B22 Brake Pedal Position Sensor, ignition ON.
  2. Test for less than 1 V between the low reference circuit terminal 1 and ground.
    • If 1 V or greater 
    1. Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module, ignition ON.
    2. Test for less than 1 V between the low reference circuit 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.
    • Go to next step: If less than 1 V 
  3. Test or replace the B22 Brake Pedal Position Sensor.

Stop Lamps Malfunction

  1. Ignition OFF, exterior lamps OFF, all doors closed, open and close drivers door, disconnect the harness connector at the appropriate component listed below. It may take up to 2 min for all vehicle systems to power down.
    • E5AS Stop/Turn Signal Lamp - Left Upper (X88 without T89)
    • E5AT Stop/Turn Signal Lamp - Left Lower (X88 without T89)
    • E5AU Stop/Turn Signal Lamp - Right (X88 without T89)
    • E5AV Stop/Turn Signal Lamp - Right Lower (X88 without T89)
    • E5L Stop Lamp - Left (X88 with T89)
    • E5R Stop Lamp - Right (X88 with T89)
    • E42L Tail Lamp Assembly - Left (X75/Z88)
    • E42R Tail Lamp Assembly - Right (X75/Z88)
  2. Test for less than 15 Ω between the appropriate ground circuit terminal listed below and ground.
    • E5AS Stop/Turn Signal Lamp - Left Upper socket terminal (X88 without T89)
    • E5AT Stop/Turn Signal Lamp - Left Lower socket terminal (X88 without T89)
    • E5AU Stop/Turn Signal Lamp - Right Upper socket terminal (X88 without T89)
    • E5AV Stop/Turn Signal Lamp - Right Lower socket terminal (X88 without T89)
    • E5L Stop Lamp - Left socket terminal (X88 with T89)
    • E5R Stop Lamp - Right socket terminal (X88 with T89)
    • E42L Tail Lamp Assembly - Left terminal 6 (X75/Z88)
    • E42R Tail Lamp Assembly - Right terminal 6 (X75/Z88)
    • If 15 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.
    • Go to next step: If less than 15 Ω 
  3. Connect a test lamp between the appropriate control circuit terminal listed below and ground, ignition ON.
    • E5AS Stop/Turn Signal Lamp - Left Upper socket terminal (X88 without T89)
    • E5AT Stop/Turn Signal Lamp - Left Lower socket terminal (X88 without T89)
    • E5AU Stop/Turn Signal Lamp - Right Upper socket terminal (X88 without T89)
    • E5AV Stop/Turn Signal Lamp - Right Lower socket terminal (X88 without T89)
    • E5L Stop Lamp - Left socket terminal (X88 with T89)
    • E5R Stop Lamp - Right socket terminal (X88 with T89)
    • E42L Tail Lamp Assembly - Left terminal 4 (X75/Z88)
    • E42R Tail Lamp Assembly - Right terminal 4 (X75/Z88)
  4. Verify the test lamp turns ON and OFF when commanding the appropriate Stop Lamp ON and OFF with a scan tool.
    • If the test lamp is always OFF 
    1. Ignition OFF, disconnect the appropriate harness connector listed below at the K9 Body Control Module.
      • X4
      • X5 left stop/turn signal lamp (X88 without T89)
    2. Test for infinite resistance between the control circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: 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 appropriate harness connector listed below at the K9 Body Control Module, ignition ON.
      • X4
      • X5 left stop/turn signal lamp (X88 without T89)
    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.
    • Go to next step: If the test lamp turns ON and OFF 
  5. Test or replace the stop lamp.

Center High Mount Stop Lamp Malfunction

  1. Ignition OFF, exterior lamps OFF, all doors closed, open and close drivers door, disconnect the harness connector at the E6 Center High Mounted Stop Lamp. It may take up to 2 min for all vehicle systems to power down.
  2. Test for less than 15 Ω between the ground circuit terminal B and ground.
    • If 15 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.
    • Go to next step: If less than 15 Ω 
  3. Connect a test lamp between the control circuit terminal A and ground, ignition ON.
  4. Verify the test lamp turns ON and OFF when commanding the Center Stop 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.
      • Go to next step: 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.
    • Go to next step: If the test lamp turns ON and OFF 
  5. Test or replace the E6 Center High Mounted Stop Lamp.
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