Vehicle Speed Sensor

1. Remove instrument cluster. Loosen screws for terminals "A" and "B" on rear of instrument cluster. SeeFig 1 . DO NOT loosen screws too much or resistance can not be measured properly. Connect ohmmeter between speedometer terminals "A" and "B" on rear of instrument cluster.
2. Insert a screwdriver into speedometer cable receptacle and rotate speedometer shaft. If ohmmeter needle does not pulsate 4 times per shaft revolution, replace speedometer.

Fig 1: Checking Vehicle Speed Sensor

Courtesy of MAZDA MOTORS CORP.

Remove vehicle speed sensor. Connect AC voltmeter (5-volt scale) between vehicle speed sensor terminals. SeeFig 2 . Rotate vehicle speed sensor driven gear gear by hand. If voltage pulses are detected, vehicle speed sensor is okay. If voltage pulses are not detected, replace vehicle speed sensor.

Fig 2: Checking Vehicle Speed Sensor

Courtesy of MAZDA MOTORS CORP.