FD4 - Check For BOO Circuit Cycling

- Key Off.

- Disconnect PCM. Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.

- Install breakout box, leave PCM disconnected.

- DVOM on 20 volt scale.

- Measure the voltage between BOO Test Pin and Test Pins 76 and 77 at the breakout box while pressing and releasing the brake.

- Does the voltage cycle?

YES -- REPLACE PCM. REMOVE breakout box. Rerun self-test. Diagnostic Subroutines (DSR) - Extracting Codes

NO -- SERVICE open in BOO circuit between PCM and BOO connection to stoplamp circuit. Rerun self-test. Diagnostic Subroutines (DSR) - Extracting Codes