Air Intake Control Circuit

1AR-FE ENGINE CONTROL: 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 Air Intake Control Valve (AICV). This system reduces intake noise and increases engine power at low-to-high engine speed range.

When the engine is operating in the low-to-mid speed range, this control operates the air intake control valve to close one of the air cleaner inlets. When the engine speed is more than 3600 rpm and the opening angle of the throttle valve is more than 60°, the ECM activates the Vacuum Switching Valve (VSV) and opens the air intake control valve.





WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

1. PERFORM ACTIVE TEST USING TECHSTREAM (ACTIVATE THE VSV FOR AICS)

(a) Disconnect the 2 hoses from the VSV for air intake control valve.





(b) Connect the Techstream to the DLC3.

(c) Turn the ignition switch to ON and turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine / Active Test / Activate the VSV for AICS.

(e) Check the operation of the VSV when the VSV is operated by the Techstream.

OK:





Text in Illustration





(f) Reconnect the 2 hoses to the VSV for air intake control valve.

NG -- INSPECT VACUUM SWITCHING VALVE (VSV FOR AICV)
OK -- Continue to next step.

2. INSPECT VACUUM TANK

(a) Inspect the vacuum tank Testing and Inspection.

NG -- REPLACE AIR CLEANER CASE SUB-ASSEMBLY
OK -- Continue to next step.

3. INSPECT INTAKE AIR CONTROL VALVE (FOR INTAKE AIR CONTROL SYSTEM)

(a) Inspect the intake air control valve assembly Intake Air Control Valve Actuator (for Intake Air Control System).

NG -- REPLACE AIR CLEANER CASE SUB-ASSEMBLY

OK -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Symptom Related Diagnostic Procedures

4. INSPECT VACUUM SWITCHING VALVE (VSV FOR AICV)

(a) Inspect the VSV for air intake control valve Vacuum Switching Valve (for Intake Air Control System).

NG -- REPLACE VACUUM SWITCHING VALVE (VSV FOR AICV)
OK -- Continue to next step.

5. CHECK TERMINAL VOLTAGE (POWER SOURCE OF VACUUM SWITCHING VALVE FOR AICV)

(a) Disconnect the VSV for air intake control valve connector.





(b) Turn the ignition switch to ON.

(c) Measure the voltage according to the value(s) in the table below.

Standard Voltage:





Text in Illustration





(d) Reconnect the VSV for air intake control valve connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (EFI MAIN RELAY - VSV FOR AIR INTAKE CONTROL VALVE)
OK -- Continue to next step.

6. CHECK HARNESS AND CONNECTOR (VSV FOR AIR INTAKE CONTROL VALVE - ECM)

(a) Disconnect the VSV for air intake control valve connector.

(b) Disconnect the ECM connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance (Check for Open):





Standard Resistance (Check for Short):





(d) Reconnect the ECM connector.

(e) Reconnect the VSV for air intake control valve connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE ECM Removal