Metro L4-079 1.3L VIN 9 TBI (1995)
Idle Speed Control Motor: Description and Operation
Idle Speed Control (ISC) Motor
IDLE SPEED CONTROL MOTOR
The Idle Speed Control (ISC) motor installed to the Throttle Body Fuel Injection (TBI) unit consists of a DC motor, gears, plunger and idle
switch. According to the signal from the Engine Control Module (ECM), the ISC motor moves the plunger to control the throttle valve opening.
The idle switch, consisting of a hall IC, magnet and spring, detects whether or not the ISC motor plunger is contacting the throttle lever screw. If
the plunger is contacting the throttle lever screw, the idle switch sends an "ON" signal to the ECM. When the plunger is not in contact with the
throttle lever screw, the idle switch will send an "OFF," signal to the ECM.
NOTICE: The ISC motor and throttle lever screw are preset at the factory. The ISC motor must not be removed from the TBI unit or
disassembled otherwise damage to the ISC motor and/or the throttle valve may occur. If the ISC motor needs to be placed, refer to Service and
Repair under this heading.
