Engine Mount: Testing and Inspection

3MZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: Active Control Engine Mount System

Active Control Engine Mount System

DESCRIPTION





The Active Control Engine Mount (ACM) system decreases engine vibration at engine idling using the ACM VSV. The VSV is controlled by a pulse signal transmitted to the VSV from the ECM. The frequency of this pulse signal is matched to the engine speed to decrease engine vibration.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK VACUUM HOSES





(a) If the hose is damaged, replace the vacuum hose assembly.
(b) Check the air and vacuum hoses for looseness, disconnection and blockage.
NG -- REPAIR OR REPLACE VACUUM HOSES
OK -- Continue to next step.
2. CHECK VACUUM





(a) Start the engine.
(b) Disconnect the vacuum hose from the air cleaner cap.
(c) Check that the disconnected port located on the vacuum tank applies suction to your finger.
OK:
Vacuum pressure exists.
(d) Reconnect the vacuum hose.
NG -- CHECK AND REPLACE VACUUM SOURCE AND HOSES
OK -- Continue to next step.
3. INSPECT ECM





(a) Connect the oscilloscope between terminals ACM and E1 of the ECM connectors.
(b) Warm up the engine to normal operating temperature.
(c) Turn the A/C switch on.
(d) Measure the voltage between terminals ACM and E1 of the ECM connectors.
Standard voltage:





OK -- INSPECT DUTY VACUUM SWITCHING VALVE (OPERATION)
NG -- Continue to next step.
4. INSPECT DUTY VACUUM SWITCHING VALVE (RESISTANCE)





(a) Disconnect the VSV for ACM connector.
(b) Measure the resistance between terminals 1 and 2.
Standard resistance:
19 to 21 Ohms at 20°C (68°F)
(c) Reconnect the VSV for ACM connector.
NG -- REPLACE DUTY VACUUM SWITCHING VALVE
OK -- Continue to next step.
5. CHECK HARNESS AND CONNECTOR (VSV FOR ACM - ECM, VSV FOR ACM - EFI RELAY)





(a) Check the wire harness between the VSV for ACM connector and the ECM connector.
(1) Disconnect the VSV for ACM connector.
(2) Disconnect the ECM connector.
(3) Measure the resistance between the terminals of the wire harness side connectors and body ground.
Standard resistance:
Check for open
Check for open









(4) Reconnect the ECM connector.
(b) Check the wire harness between the VSV for ACM and the EFI relay.
(1) Remove the EFI relay from the fusible link block.
(2) Measure the resistance between the wire harness side connectors.
Standard resistance:
Check for open





(3) Reconnect the VSV for ACM connector.
(4) Reinstall the EFI relay.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE ECM
6. INSPECT DUTY VACUUM SWITCHING VALVE (OPERATION)





(a) Remove the VSV for ACM.
(b) Check operation of the VSV for ACM when positive battery voltage is applied to the terminals of the VSV for ACM connector.
Positive battery voltage is not applied:
The air from pipe G is flowing out through pipes E and H.
Positive battery voltage is applied:
The air from pipe F is flowing out through pipes E and H.
(c) Reinstall the VSV for ACM.
NG -- REPLACE DUTY VACUUM SWITCHING VALVE
OK -- Continue to next step.
7. INSPECT FRONT ENGINE MOUNTING INSULATOR ASSEMBLY





(a) Disconnect the vacuum hose from the front engine mount insulator.
(b) Using a vacuum pump, apply vacuum of 80 kPa (600 mmHg, 25 in.Hg) and wait for 1 minute.
(c) Check that there is no change in the needle movement of the vacuum pump gauge.
(d) Check that there is no fluid leakage caused by a break in the diaphragm.
OK:
Front engine mounting insulator assembly is normal.
(e) Reconnect the vacuum hose.
NG -- REPLACE FRONT ENGINE MOUNTING INSULATOR ASSEMBLY
OK -- SYSTEM OK