Idle Control System
When the engine is cold, the A/C compressor is on, the transmission is in gear, the brake pedal is pressed, the power steering load is high, or the alternator is charging, the ECM/PCM controls current to the idle air control (IAC) valve (K24A3 engine: throttle actuator) to maintain the correct idle speed. Refer to the system diagram to see the functional layout of the system.
Brake Pedal Position Switch
The brake pedal position switch signals the ECM/PCM when the brake pedal is pressed.
Idle Air Control (IAC) Valve (K20A6 engine)
To maintain proper idle speed, the IAC valve changes the amount of air bypassing the throttle body in response to an electrical signal from the ECM/PCM.
Power Steering Pressure (PSP) Switch
The PSP switch signals the ECM/PCM when the power steering load is high.