DTC 15

OPERATION
MPS is a variable resistor type, and is integrated in the ISC servo system. The sliding pin of MPS is in contact with the end of the plunger. Therefore, as the plunger moves, the internal resistance of MPS varies. This leads to the variation of the output Voltage. MPS detects the plunger position of the

ISC servo system, and sends the signal to ECU. ECU processes the MPS signal, idle signal, coolant temperature signal, load signal (A/T & A/C) and vehicle speed signal to control the opening angle of the throttle valve and revolution speed during engine idling.

TROUBLESHOOTING HINTS
Since idling is not controlled when MPS is troubled, idling may not be evenly maintained.

INSPECTION





Using Multi-use tester

NOTE The motor position sensor output Voltage may be about 500 mV higher than indicated above when the vehicle is new [driven approximately 500 km (300 miles) or less).

CAUTION Before shifting the select lever to the "D" range, apply the brakes to prevent the vehicle from moving forward.











HARNESS INSPECTION

SENSOR INSPECTION





(1) Disconnect the motor position sensor connector, and connect the special tool (test harness) to the connector on motor position sensor side.

CAUTION Never connect the special tool to the connector on harness side.

(2) Measure the resistance between terminal (1) (black clip of special tool) and terminal (3) (white clip) of the motor position sensor connector.

Standard value: 4-6 K Ohms





(3) Disconnect the idle speed control servo connector and connect the special tool to the connector on idle speed control servo side.

CAUTION Never connect the special tool to the connector on harness side.





(4) Connect a 6V DC power supply between terminals (1) and (2) of the idle speed control servo connector to activate (extend and retract) the idle speed control servo. Measure the resistance between terminal (1) (black clip of special tool) and terminal (2) (red clip) of the motor position sensor connector.

Standard value: Smooth increase/decrease in accordance with extension and retraction of idle speed control servo plunger.

(5) If there is a deviation from the standard value, or if the change is not smooth, replace the idle speed control servo assembly.