IACV Control Circuit: Procedure

Fig 1: Checking VSV Air Flow With VSV On & VSV Off

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the vacuum hose from the port F on the VSV for ACIS.
2. Connect the Techstream to the DLC3.
3. Start the engine.
4. Enter the following menus: Powertrain / Engine and ECT / Active Test / Active the VSV for Intake Control.
5. Check the VSV's air flow when switching the VSV.

   OK

   Condition	Specified Condition
   VSV is ON	Air from port E flows out through port F
   VSV is OFF	Air from port E flows out through air filter

NG → See step   4 

OK: Go to next step 

1. Check the condition of the vacuum hoses between the intake manifold, VSV for ACIS and IACV.
   1. The vacuum hoses are connected securely.
   2. Vacuum hoses are not cranked or damaged.

      OK

      The vacuum hoses are connected securely and not cracked or damaged.

NG → REPAIR OR REPLACE VACUUM HOSES 

OK: Go to next step 

1. Inspect the intake air control valve. Refer to ON-VEHICLE INSPECTION .

NG → REPLACE INTAKE AIR CONTROL VALVE 

OK → REPLACE ECM 

Fig 2: Checking Vacuum Switching Valve (Operation)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Check that air flows from port E to the air filter.
2. Apply positive (+) battery voltage across the terminals.
3. Check that air flows from port E to port F.

NG → REPLACE VACUUM SWITCHING VALVE 

OK: Go to next step 

Fig 3: Checking Wire Harness (Vacuum Switching Valve - ECM, Vacuum Switching Valve - Body Ground)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the V2 VSV for ACIS connector.
2. Disconnect the E4 ECM connector.
3. Measure the resistance of the wire harness side connectors.

   Standard resistance

   Tester Connection	Specified Condition
   V2-2 - E4-3 (ACIS)	Below 1 Ω
   V2-2 or E4-3 (ACIS) - Body ground	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS AND CONNECTOR 

OK: Go to next step 

Fig 4: Inspecting EFI Relay

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Remove the EFI relay from the engine room No. 2 relay block.
2. Measure the resistance of the EFI relay.

   Standard resistance

   Tester Connection	Specified Condition
   3 - 5	10 kΩ or higher
   3 - 5	Below 1 Ω (when battery voltage is applied to terminals 1 and 2)

NG → REPLACE EFI RELAY 

OK → REPLACE ECM