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
- CHECK VACUUM HOSES
- Check if the vacuum hose cap is missing.
- If the hose is damaged, replace the vacuum hose assembly.
- Check the air and vacuum hoses for looseness, disconnection and blockage.
NG : REPAIR OR REPLACE VACUUM HOSES
OK : Go to next step
- CHECK VACUUM
- Start the engine.
- Disconnect the vacuum hose from the vacuum tank.
- Check that the unconnected port located on the vacuum tank applies suction to your finger.
- Reconnect the vacuum hose.
NG : CHECK AND REPLACE VACUUM SOURCE AND HOSES
OK : Go to next step
- INSPECT ECM (ACM VOLTAGE)
- Connect the oscilloscope between terminals ACM and E1 of the E7 ECM connector.
- Warm up engine to normal operating temperature.
- Turn the A/C switch on.
- Measure the voltage between terminals ACM and E1 of the E7 ECM connector.
Standard voltage
ECM (ACM VOLTAGE)Condition Specified Condition Shift position is D range, and engine speed is 850 rpm or less Pulse generation Shift position is D range, and engine speed is 950 rpm or more 9 to 14 V Shift position is P range 9 to 14 V OK : GO TO STEP 6
NG : Go to next step
- INSPECT VSV FOR ACM (RESISTANCE)
- Disconnect the V2 VSV for ACM connector.
- Measure the resistance between the terminals 1 and 2.
Standard resistance
VSV FOR ACM (RESISTANCE)Tester Connection Condition Specified Condition 1-2 20°C (68°F) 19 to 20 Ω NG : REPLACE VSV
OK : Go to next step
- CHECK HARNESS AND CONNECTOR (VSV FOR ACM - ECM, VSV FOR ACM - EFI MAIN RELAY)
- Check the wire harness between the VSV for ACM and ECM.
- Disconnect the V2 VSV connector for ACM.
- Disconnect the E7 ECM connector.
- Measure the resistance of the wire harness side connectors.
Standard resistance
VSV FOR ACM - ECM, VSV FOR ACM - EFI MAIN RELAYTester Connection Specified Condition V2-2 - E7-6 (ACM) Below 1 Ω V2-2 or E7-6 (ACM) - Body ground 10 kΩ or higher - Check the wire harness between the VSV and EFI MAIN relay.
- Check the EFI No. 2 fuse from the fusible link block.
- Remove the EFI No. 2 fuse from the fusible link block.
- Measure the resistance of the EFI No. 2 fuse.
Standard resistance:
Below 1 Ω
- Reinstall the EFI No. 2 fuse.
- Disconnect the V3 VSV for ACM connector.
- Remove the EFI MAIN relay from the engine room J/B.
- Measure the resistance of the wire harness side connectors.
- Check the EFI No. 2 fuse from the fusible link block.
Standard resistance
VSV FOR ACM - EFI MAIN RELAYTester Connection Specified Condition V2-1 (VSV for ACM) - EFI MAIN relay terminal 3 Below 1 Ω Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
NG : REPAIR OR REPLACE HARNESS OR CONNECTOR
OK : REPLACE ECM
- Check the wire harness between the VSV for ACM and ECM.
- INSPECT VSV FOR ACM (OPERATION)
- Remove the VSV.
- Check operation of the VSV when battery positive voltage is applied to the terminals of the VSV connector.
Battery positive voltage is not applied:
The air from pipe G is flowing out through pipes E and H.
Battery positive voltage is applied:
The air from pipe F is flowing out through pipes E and H.
NG : REPLACE VSV FOR ACM
OK : Go to next step
- INSPECT FRONT ENGINE MOUNT INSULATOR
- Disconnect the vacuum hose from the front engine mount insulator.
- Using MITYVAC (Hand-held Vacuum Pump), apply a vacuum of 80 kPa (600 mmHg, 25 in.Hg) and wait for 1 minute.
- Make sure there is no needle movement on the MITYVAC.
- Check that there is no fluid leakage caused by a broken lower diaphragm.
NG : REPLACE FRONT ENGINE MOUNT INSULATOR
OK : SYSTEM OK
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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