Test O - Brake On/Off (Boo)
- Code 74 Displayed. If brake was NOT pressed during Engine Running Self-Test, repeat test and press brake pedal once during test. If pedal was pressed, go to next step.
- Turn key OFF and wait 10 seconds. Disconnect 60-pin ECA connector. Inspect for and repair any damaged wiring. Install breakout box, leaving ECA disconnected. Set DVOM to 20 volt scale. Measure voltage between test pin 2 and test pin 40 while applying and releasing brake. If voltage cycles, replace ECA and repeat step. If voltage does not cycle, go to next step.
- Turn key OFF. Leave breakout box installed with ECA disconnected. Set DVOM to 200 ohm scale. Disconnect BOO circuit from 14290 (12-pin connector). Measure resistance between test pin 2 and ground. If reading is higher than 5 ohms, repair BOO circuit short to ground. If reading is not higher than 5 ohms, check brake light circuit.
- Code 75 Displayed. Turn key OFF and wait 10 seconds. Disconnect 60-pin ECA connector. Inspect for and repair any damaged wiring. Install breakout box, leaving ECA disconnected. Set DVOM to 20 volt scale. Measure voltage between test pin 2 and test pin 40 while applying and releasing brake. If voltage cycles, replace ECA and repeat step. If voltage does not cycle, go to next step.
- Turn key OFF. With breakout box installed and ECA disconnected, set DVOM to 200 ohm scale. Disconnect BOO circuit from 14290 harness (12-pin connector). Measure resistance between test pin 2 and ground. If reading is greater than 5 ohms, repair BOO circuit short to ground. If reading is less than 5 ohms, check brake light circuit.