MX-5 Miata L4-1597cc 1.6L DOHC (1992)
Idle/Bypass Air Control Valve: Description and Operation
Idle Speed Control (ISC) System
PURPOSE
Idle speed control system regulates amount of bypass air allowed around the throttle valve.
LOCATION
On throttle body.
OPERATION
The idle speed control valve is warmed by engine coolant as well as being controlled by an ECU duty signal. The amount of bypass air allowed to
flow around the throttle valve is precisely controlled by the ECU according to operating conditions sensed from several input devices, including:
^ Water thermosensor
^ Intake air thermosensor
^ Throttle sensor
^ Atmospheric pressure sensor
^ Neutral and clutch switches
^ A/C switch
^ Cooling fan switch
^ Blower control switch
^ Headlight switch
^ Power steering pressure switch
^ Ignition switch ("START" position)
^ Crank angle sensor Ne signal
