Idle Speed Motor Position Sensor: Description and Operation

The Motor Position Sensor (MPS) is a variable type sensor, installed in the Idle Speed Control (ISC) servo. Its sliding pin is in contact with the ISC plunger end and as the ISC plunger moves, the internal resistance of the MPS 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 and vehicle speed signal.