IACV Control Circuit: Wiring Diagram

1. Disconnect the vacuum hose from port F on the vacuum switching valve (for ACIS).
2. Connect the intelligent tester to the CAN VIM. Then connect the CAN VIM to the DLC3.
3. Start the engine.
4. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / INTAKE CTL VSV1. Operate the ACIS VSV.
5. Check the VSV air flow when switching the VSV.

OK: Go to next step 

Fig 2: Checking VSV Air Flow

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: GO TO STEP   4 

OK: Go To Next Step 

1. Check the condition of the vacuum hoses between the intake manifold, vacuum switching valve (for ACIS) and IACV.
   1. The vacuum hoses are connected securely.
   2. The vacuum hoses are not cracked 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 intake air control valve (ON-VEHICLE INSPECTION ).

NG: REPLACE INTAKE AIR CONTROL VALVE 

OK: REPLACE ECM 

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.

Fig 3: Inspecting Vacuum Switching Valve

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPLACE VACUUM SWITCHING VALVE 

OK: Go To Next Step 

1. Check harness and connector (ELECTRONIC CIRCUIT INSPECTION PROCEDURE ).

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: REPLACE ECM