Constant Idle Speed System

Fig. 1 Constant idle speed system:

Fig. 2 Constant idle speed system wiring diagram:

The CIS system, Figs. 1 and 2, consists of an electronic control module, air control valve, temperature sensor and a microswitch. The electronic control module receives information on engine speed, engine coolant temperature, air conditioning mode and throttle position. The electronic control module receives this information from the ignition coil, temperature sensor, A/C control panel and microswitch. The electronic control module processes the information and regulates the air control valve to maintain a desired (according to engine operating conditions) engine idle speed. The air control valve consists of an electric motor and controls engine idle speed by increasing or decreasing the amount of air flow past the throttle valves. The electronic control module increases engine idle speed during cold engine operation. The engine idle speed decreases as engine coolant temperature increases.