Test FD - Brake On/Off Switch
Perform a comprehensive visual inspection of wiring and harness connectors at ECA and brake switch assembly. Repair or replace defective wiring or components as necessary.
- Brake Switch Operation At ECA: Install breakout box. Disconnect ECA connector. Turn ignition on. Using a DVOM, measure voltage between pins No. 3 and 40. Measure voltage between pins No. 3 and 20. Voltmeter should read less than 4 volts with brake pedal released and more than 10 volts with pedal depressed. If DVOM readings were correct, replace ECA assembly. If DVOM readings were incorrect, proceed to next step.
- Voltage From Brake Switch: With key on, measure voltage between brake switch White/Green wire and ground. Voltmeter should read less than 4 volts with brake pedal released and more than 10 volts with pedal depressed. If DVOM readings were correct, repair open or short to power in wiring harness between ECA terminal No. 1J and brake switch. If DVOM reading is incorrect, proceed to next step.
- Power To Brake Switch: With key on, measure voltage between brake switch Green/White wire and ground. If DVOM reads more than 10 volts, adjust or replace brake switch. If DVOM reads less than 10 volts, go to next step.
- Power At Battery: With key on, measure voltage across vehicle battery terminals. If DVOM reading is more than 10 volts, replace bad fuse or repair open in Green/Yellow wire between vehicle battery and brake switch. If DVOM reads less than 10 volts, proceed to TEST B , step 1.