Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Inspection Procedure
- PERFORM ACTIVE TEST BY TECHSTREAM (VACUUM SWITCHING VALVE)
- Disconnect the vacuum hose from port F on the vacuum switching valve (for ACIS).
- Connect the Techstream to the DLC3.
- Start the engine.
- Enter the following menus:/Engine and ECT/Active Test/Active the VSV for Intake Control. Operate the ACIS VSV.
- Check the VSV air flow when switching the VSV.
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
OK
TESTER CONDITION AND SPECIFIED CONDITIONTester 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 the air filter
NG: Go to step 4
OK: Go to Next Step
- CHECK VACUUM HOSES (INTAKE MANIFOLD - VACUUM SWITCHING VALVE, VACUUM SWITCHING VALVE - INTAKE AIR CONTROL VALVE)
- Check the condition of the vacuum hoses between the intake manifold, vacuum switching valve (for ACIS) and IACV.
- The vacuum hoses are connected securely.
- 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
- Check the condition of the vacuum hoses between the intake manifold, vacuum switching valve (for ACIS) and IACV.
- INSPECT INTAKE AIR CONTROL VALVE
- Inspect the intake air control valve (See INSPECTION ).
NG: REPLACE INTAKE AIR CONTROL VALVE
OK: REPLACE ECM
- INSPECT VACUUM SWITCHING VALVE (OPERATION)
- Check that air flows from port E to the air filter.
- Apply positive (+) battery voltage across the terminals.
- Check that air flows from port E to port F.
NG: REPLACE VACUUM SWITCHING VALVE
OK: Go to Next Step
- CHECK HARNESS AND CONNECTOR (VACUUM SWITCHING VALVE - ECM, VACUUM SWITCHING VALVE - EFI NO. 2 FUSE)
- Check the wire harness between the VSV for ACIS and connector the ECM connector.
- Disconnect the V9 VSV for ACIS connector.
- Disconnect the E5 and E7 ECM connectors.
- Measure the resistance between the wire harness side connectors.
Standard resistance (Check for open)
STANDARD RESISTANCETester Connection Specified Condition VSV for ACIS (V9-2) - ACIS (E5-33) Below 1 Ω Standard resistance (Check for short)
STANDARD RESISTANCETester Connection Specified Condition VSV for ACIS (V9-2) or ACIS (E5-33) - E1 (E7-1) 10 kΩ or higher
- Check the wire harness between the VSV for ACIS connector and the EFI relay.
- Disconnect the V9 VSV for ACIS connector.
- Remove the EFI relay from the engine room R/B
- Measure the resistance between the wire harness side connectors.Fig 3: Checking Harness And Connector (Vacuum Switching Valve - ECM, Vacuum Switching Valve - EFI No. 2 Fuse)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Standard resistance (Check for open)
STANDARD RESISTANCETester Connection Specified Condition VSV for ACIS (V9-1) - EFI relay terminal 3 of R/B Below 1 Ω
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: REPLACE ECM
- Check the wire harness between the VSV for ACIS and connector the ECM connector.
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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