Active Control Engine Mount System

DESCRIPTION

LOCATION

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

1 CHECK VACUUM HOSES

1. 1
   If the hose is damaged, replace the vacuum hose assembly.
2. 2
   Check the air and vacuum hoses for looseness, disconnection and blockage.

2 CHECK VACUUM

1. 1
   Start the engine.
2. 2
   Disconnect the vacuum hose from the air cleaner cap.
3. 3
   Check that the disconnected port located on the vacuum tank applies suction to your finger.

3 INSPECT ECM

1. 1
   Connect the oscilloscope between terminals ACM and E1 of the E9 and E11 ECM connectors.
2. 2
   Warm up the engine to normal operating temperature.
3. 3
   Turn the A/C switch on.
4. 4
   Measure the voltage according to the value(s) in the table below.

Standard voltage

4 INSPECT DUTY VACUUM SWITCHING VALVE (RESISTANCE)

1. 1
   Disconnect the V3 VSV for ACM connector.
2. 2
   Measure the resistance according to the value(s) in the table below.

   Standard resistance: 19 to 21 Ω at 20C (68F)

3. 3
   Reconnect the VSV for ACM connector.

5 CHECK HARNESS AND CONNECTOR (VSV FOR ACM - ECM)

1. 1
   Check the wire harness between the VSV for ACM connector and the ECM connector.
2. 2
   Disconnect the V3 VSV for ACM connector.
3. 3
   Disconnect the E9 ECM connector.
4. 4
   Measure the resistance according to the value(s) in the table below.

Standard resistance: Check for open

Check for open

4. Reconnect the ECM connector.

6 INSPECT FUSE (EFI NO. 2 FUSE)

1. 1
   Remove the EFI No. 2 fuse from the engine room junction block.
2. 2
   Measure the resistance according to the value(s) in the table below.

7 INSPECT RELAY (EFI RELAY)

1. 1
   Remove the EFI relay from the engine room junction block.
2. 2
   Measure the resistance according to the value(s) in the table below.

Standard resistance

3. Reinstall the EFI relay.

8 CHECK HARNESS AND CONNECTOR (VSV FOR ACM - EFI RELAY)

1. 1
   Check the wire harness between the VSV for ACM and the EFI relay.
2. 2
   Remove the EFI relay from the engine room junction block.
3. 3
   Measure the resistance according to the value(s) in the table below.

Standard resistance: Check for open

1. 1
   Reconnect the VSV for ACM connector.
2. 2
   Reinstall the EFI relay.

CHECK ECM POWER SOURCE CIRCUIT

9 INSPECT DUTY VACUUM SWITCHING VALVE (OPERATION)

1. 1
   Remove the VSV for ACM.
2. 2
   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.

3. 3
   Reinstall the VSV for ACM.

10 INSPECT ENGINE MOUNTING INSULATOR ASSEMBLY FRONT

1. 1
   Disconnect the vacuum hose from the front engine mount insulator.
2. 2
   Using a vacuum pump, apply vacuum of 80 kPa (600 mmHg, 25 in.Hg) and wait for 1 minute.
3. 3
   Check that there is no change in the needle movement of the vacuum pump gauge.
4. 4
   Check that there is no fluid leakage caused by a break in the diaphragm.

SYSTEM OK