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Circuit/System Verification

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  1. Ignition ON, observe the scan tool BCM Stop Lamp Switch Status parameter while pressing and releasing the brake pedal. The reading should change between 1 count and approximately 1023 counts.
    • If not the specified value, refer to the Stop Lamp Switch Circuit Test below.
  2. Ignition ON, observe the scan tool TCM Brake Switch parameter while pressing and releasing the brake pedal. The reading should change between Pressed and Released.
    • If not the specified value, refer to the Brake Switch Circuit Test below.
  3. Ignition ON, observe the left, and right stop lamps while pressing and releasing the brake pedal. The stop lamps should turn on and off.
    • If the left and or right stop lamps are always on or inoperative, refer to the Stop Lamp Circuit Test below.
  4. Connect a test lamp between the relay side of the CHMSL fuse and ground.
  5. Verify that the test lamp turns on and off while pressing and releasing the brake pedal.
    • If the test lamp does not turn on and off while changing between the commanded states, refer to the CHMSL Relay Control Circuit Test below.
  6. If the center high mount stop lamp is always on or inoperative refer to the CHMSL Circuit Test below.
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