Idle Position Switch: Operation

• The idle position switch functions to convert (to high/low level voltage) data as to whether the accelerator is depressed or released, and to input that voltage (as signals) to the engine control unit. The engine control unit, based upon those signals, regulates the idle speed control servo.
• Voltage within the engine control unit is applied, by way of the resistance, to the idle position switch. When the foot is taken off the accelerator, the idle position switch is switched on, so the current is grounded. As a result, the idle position switch terminal voltage changes from high to low level. See Fig 1 .

Fig 1: Identifying Idle Position Switch Circuit

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.