Code 10, Stoplight Switch On Constantly
- Turn ignition off. Disconnect RWAL ECM connector. Turn ignition on. Measure voltage between ECM terminal No. 8 and ground. See Fig 1 . If reading is 10-15 volts, replace/adjust stoplight switch or repair short in Green/White wire between stoplight switch and RWAL ECM. If reading is less than 10-15 volts, replace RWAL ECM.