California Only

The ECM activates the idle air control solenoid valve in advance to control the amount of by-pass air flowing through the throttle valve in relation to signals emitted from the crankshaft position sensor, engine coolant temperature sensor, pressure sensor and A/C switch. etc., so that the proper idle speed specified for each engine load is achieved.
The idle air control solenoid valve utilizes a duty solenoid design which the opening area of bypass port is changed by the amount of rotary valve moving. For this reason, the by-pass air flow is regulated by controlling the duty ratio. The relationship between the duty ratio, rotary valve moving and by-pass air flow is as follows:
- Duty ratio (high) -> Increases rotary valve moving and by-pass air flow.

Bypass air control features the following advantages:
- Compensation for engine speed under A/C (air conditioning) system and electrical loads.
- Increase in idle speed during early stage of warm up period.
- A dashpot function during the time the throttle valve is quickly closed.
- Prevention of engine speed variations over time.