Stoplight Switch Circuit
- Check if stoplights are functioning correctly. If stoplights function correctly, go to next step. If stoplights do not function correctly, check stoplight circuit, and repair as necessary.
- Ensure ignition switch is in OFF position. Disconnect ECM wiring harness connector. Turn ignition switch to ON position. Using DVOM, measure voltage between ECM connector terminal No. 29 (Green wire) and ground with brake pedal fully depressed. See Figure . If battery voltage does not exist, repair or replace wiring harness between stoplight switch and ECM. If battery voltage exists, stoplight switch circuit is okay. Replace faulty ECM.