Speed Sensor

Turn ignition off. Disconnect electrical connector from speed sensor mounted on transmission. See Fig 1 . Remove speed sensor. Quickly rotate speed sensor gear counterclockwise by hand. Measure AC voltage across speed sensor connector terminals. If voltmeter does not deflect between zero and about .5 volt AC, replace speed sensor.

Fig 1: Testing Vehicle Speed Sensor

Courtesy of NISSAN MOTOR CO., U.S.A.