Idle Speed Motor Position Sensor: Description and Operation

The MPS is a variable resistor type sensor located in the ISC servo. The sensor incorporates a sliding pin which is in contact with the plunger end and asthe plunger moves, the internal resistance of the MPS (Output voltage) changes. The MPS senses the ISC servo plunger position and sends the signal to the ECU. The ECU controls the valve opening and the idle speed by using the MPS signal, idle signal, engine coolant temperature signal, load signals from the auto/trans. and a/c, and vehicle speed signal.