Speed Sensor Check
- Jack up front of vehicle and support with safety stands. Block rear wheels and set parking brake.
- Connect voltmeter positive probe to Yellow/Black wire terminal at emission control box connector. Connect negative probe to known good ground (Black ground wire). See Fig 1. Start engine.
- Select 2nd gear and accelerate engine slowly while observing voltmeter. Voltmeter should show battery voltage above 5-15 MPH (above 20 MPH on Accord and Prelude). With vehicle speed below 5 MPH (10 MPH on Accord and Prelude), voltmeter should show no voltage.
- If no voltage exists above specified MPH, check for bad electrical connections, blown fuse, or faulty speed sensor. Repair or replace as necessary. If voltage readings do not agree with specified MPH range, install new speedometer and speed sensor assembly and repeat test.
Courtesy of AMERICAN HONDA MOTOR CO., INC.