Secondary Speed Sensor

The secondary speed sensor is installed to side cover of transaxle.
The secondary speed sensor detects secondary pulley speed.
The secondary speed sensor generates the ON-OFF pulse (short waveform) in proportion to the rotating body speed which is "The higher the rotating body speed is, the faster the change cycle is". The TCM judges the rotating speed from the changing cycle of this pulse signal.

Courtesy of NISSAN NORTH AMERICA, INC.