Entering Self-Diagnostics: Notes

System monitors operation of components and switches. When component or switch is operated according to a set procedure, LED will display a 3-digit code. Failure to display a code indicates control unit has failed to detect operation of component/switch. In this case, fault lies with component/switch or associated connectors and wiring.

Functional check system can also test whether components/switches are correctly wired. For example, it can check whether permanent/magnet generator (engine speed sensor) and wiring are intact if engine fails to start.