Air Regulator Control System

Fig. 3 Air Regulator Control System:

CIRCUIT OPERATION
The air regulator system provides a means for cold fast idle.
When the engine is cold a passage in the regulator is open to allow air to by-pass the throttle plate allowing fast idle. The regulator has a bi-metal heater and rotary shutter that closes the passage as the heater element warms. The element is controlled by the ECU via the fuel pump relay.
The ECU supplies the ground circuit for the fuel pump relay for a few seconds after the ignition switch is turned on. If the ECU receives a 1° signal from the crank angle sensor, indicating the engine is on or starting, it continuously supplies the circuit. If the 1° signal is not present, indicating a stalled engine, the ECU does not supply the ground circuit thereby preventing excessive battery discharge.

Fig. 4 Air Regulator Control Operation:

Refer to the chart for conditions necessary for air regulator operation.

Idle Air Control Valve-Air Regulator:

AIR REGULATOR
The air regulator allows air to bypass the throttle plate when the engine is cold, providing fast idle. The ECU supplies the ground circuit to the bimetal heater and rotary shutter that closes off the passage as the element warms. It is located on the intake plenum.