Idle Speed Motor Position Sensor: Description and Operation

Idle Switch / Motor Position Sensor Locations:

The Motor Position Sensor (MPS) is a variable resistor type sensor, installed in the Idle Speed Control (ISC) servo. Its sliding pin is in contact with the plunger end and as the plunger moves, the internal resistance and output voltage of the MPS changes. The MPS senses ISC servo plunger position and sends the signal to the ECU. The ECU controls the valve opening, and consequently the idle speed by using the MPS signal, idle signal, engine coolant temperature signal, load signals (automatic transaxle and air conditioner) and vehicle speed signal.