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Home >> Nissan-Datsun >> 2004 >> Altima SE, Standard >> Repair and Diagnosis >> Engine Performance >> Engine Control System - 3.5L >> Electronic Controlled Engine Mount >> Diagnostic Procedure

Diagnostic Procedure

  1. CHECK OVERALL FUNCTION 

    With CONSULT-II 

    1. Start engine and warm it up to normal operating temperature.
    2. Select "ENGINE MOUNTING" in "ACTIVE TEST" mode with CONSULT-II and touch "ON/OFF" on the CINSULT-II screen.
    3. Check that the motor operating sound is heard from front electronic controlled engine mount and rear electronic controlled engine mount for about 0.5 seconds according to the switching condition of "ENGINE MOUNTING".
      Fig 1: CONSULT-II Diagnosis Function Display
      G02886070Courtesy of NISSAN MOTOR CO., U.S.A.

    Without CONSULT-II 

    1. Make sure that gear position is P.
    2. Start engine and let it idle.
    3. Change the engine speed from idle to more than 1, 000 RPM and then return to idle (with vehicle stopped).
    4. Check that the motor operating sound is heard from front electronic controlled engine mount and rear electronic controlled engine mount for about 0.5 seconds when changing engine speed.

      It is better to hear the operating sound around the left side front wheel house.

      OK or NG

    1. OK : INSPECTION END 
    2. NG : GO TO 2.
  2. CHECK ELECTRONIC CONTROLLED ENGINE MOUNT POWER SUPPLY CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect front and rear electronic controlled engine mount harness connector.
      Fig 2: Disconnecting Front And Rear Electronic Controlled Engine Mount Harness Connector
      G02886071Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Check voltage between electronic controlled engine mount terminal 3 and ground with CONSULT-II or tester.

      Voltage: Battery voltage 

    OK or NG

    1. OK : GO TO  4.
    2. NG : GO TO 3.
      Fig 3: Checking Voltage Between Terminal 3 And Ground
      G02886072Courtesy of NISSAN MOTOR CO., U.S.A.
  3. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors E20, F32
    • 10A fuse
    • Harness for open and short between electronic controlled engine mount and battery

      : Repair harness or connectors.

  4. CHECK ELECTRONIC CONTROLLED ENGINE MOUNT OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT 
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Check harness continuity between ECM terminals and electronic engine mount terminals as follows. Refer to Wiring Diagram .
      TERMINAL CONDITION SPECIFICATION

      ECM terminal Front electronic controlled engine mount terminal Rear electronic controlled engine mount terminal
      4 1 1
      14 2 2

      Continuity should exist. 

    4. Also check harness for short to ground and short to power.

    OK or NG

    1. OK : GO TO 5.
    2. NG : Repair open circuit or short to ground or short to power in harness or connectors.
  5. CHECK ELECTRONIC CONTROLLED ENGINE MOUNT 

    Visually check front and rear electronic controlled engine mount.

    OK or NG

    1. OK : GO TO 6.
    2. NG : Replace front or rear electronic controlled engine mount.
  6. CHECK INTERMITTENT INCIDENT 

    Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    : INSPECTION END