All Models (Engine Hot)
- Jack up front of car and support with safety stands. Block rear wheels and set parking brake.
- Connect voltmeter positive probe to yellow/black wire terminal at control box connector. Connect negative probe to a suitable ground.
- Start engine. Select second gear and accelerate slowly while observing voltmeter.
- Voltmeter should show voltage above 15 MPH. Below this speed, no voltage should be shown.
- If voltage is present at the wrong speed, replace speed sensor. If no voltage is present, check fuse and related wiring and repair as necessary.