Idle Speed Control (CIS Digital Control)

Idle speed stabilizer is separate from digital control unit. The throttle switch is used to initiate idle speed control. The air control valve, located in throttle valve by-pass hose, receives signals from idle speed stabilizer.

With ignition switch in ON position and engine off, air control valve is activated. This provides a valve opening determined by coolant temperature. After engine is started, idle stabilizer adjusts idle speed based on idle stabilizer thermo switch, throttle position and engine RPM. A/C operation will also send signal to ECU, which will modify signal to the air control valve. Engine speed changes according to temperature. Engine speeds vary from 1000 RPM at 0°F (-20°C) to 720 RPM at 68°F (20°C).