Air Intake Control Circuit

3MZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: Air Intake Control Circuit

Air Intake Control Circuit

DESCRIPTION

The air cleaner is equipped with two inlets, one of which is opened or closed by the Intake Air Control (IAC) valve No. 3. This system reduces intake noise and increases engine power at low to high speed engine speeds.
When the engine is operating at low to mid speeds, this system operates the IAC valve to close one of the air cleaner inlets. When the engine speed is more than 3,200 rpm and the opening angle of the throttle valve is more than 30°, the ECM activates the VSV and opens the IAC valve No. 3.





WIRING DIAGRAM

Refer to ACIS CONTROL CIRCUIT (ACIS Control Circuit).

INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE OF TECHSTREAM (VSV FOR IAC VALVE NO. 3)





(a) Turn the ignition switch to the ON position and push Techstream main switch on.
(b) Enter the following menus: Powertrain / Engine and ECT / Active Test / Active the VSV for Intake Control. Operate the VSV.
(c) Check the operation of the VSV when the VSV is operated by Techstream.
Standard:





OK -- INSPECT VACUUM TANK
NG -- Continue to next step.
2. CHECK VSV
NG -- REPLACE INTAKE AIR CONTROL VALVE ASSEMBLY NO. 3
OK -- Continue to next step.
3. CHECK WIRE HARNESS (VSV FOR AICV - ECM, EFI RELAY)





(a) Check the wire harness between the VSV and ECM.
(1) Disconnect the VSV connector for AICV.
(2) Disconnect the ECM connector.
(3) Measure the resistance of the wire harness side connectors.
Standard resistance:









(b) Check the wire harness between the VSV and the EFI relay.
(1) Disconnect the VSV connector for AICV.
(2) Remove the EFI relay from the engine room J/B.
(3) Measure the resistance of the wire harness side connectors.
Standard resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
4. INSPECT VACUUM TANK
NG -- REPLACE VACUUM TANK
OK -- REPLACE ECM