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Home >> Infiniti >> 2007 >> QX56 AWD >> Repair and Diagnosis >> Transmission >> Transfer Case >> Trouble Diagnosis For System >> Transfer Control Device >> Diagnostic Procedure

Diagnostic Procedure

  1. CHECK POWER SUPPLY 
    1. Turn ignition switch "OFF". (Stay for at least 5 seconds.)
    2. Connect transfer control unit harness connector.
    3. Check voltage between transfer control unit harness connector terminal and ground.
      TERMINALS VOLTAGE CHART

      Connector Terminal Voltage (Approx.)
      E142 16 - Ground 0V
      22 - Ground
      E143 30 - Ground Battery voltage
      Fig 1: Checking Voltage Between Transfer Control Unit Harness Connector Terminal And Ground
      G04901509
    4. Turn ignition switch "ON". (Do not start engine.)
    5. Check voltage between transfer control unit harness connector terminals and ground.
      TERMINALS VOLTAGE CHART

      Connector Terminal Voltage (Approx.)
      E142 16 - Ground Battery voltage
      22 - Ground
      E143 30 - Ground 0V
      Fig 2: Checking Voltage Between Transfer Control Unit Harness Connector Terminals And Ground
      G04901510

    OK or NG 

    OK: GO TO 2.

    NG: Check the following. If any items are damaged, repair or replace damaged parts.

    • 10A fuse No. 26 located in the fuse and fusible link box. Refer to "POWER SUPPLY ROUTING CIRCUIT ".
    • Harness for short or open between battery and transfer shut off relay harness connector E69 terminal 1.
    • Harness for short or open between transfer shut off relay harness connector E69 terminal 2 and transfer control unit harness connector E143 terminal 30.
    • Harness for short or open between battery and transfer shut off relay harness connector E69 terminal 3.
    • Harness for short or open between transfer shut off relay harness connector E69 terminal 5 and transfer control unit harness connector E142 terminal 22.
    • Transfer shut off relay. Refer to "COMPONENT INSPECTION ".
  2. CHECK GROUND CIRCUIT 
    1. Turn ignition switch "OFF". (Stay for at least 5 seconds.)
    2. Disconnect transfer control unit harness connector.
    3. Check continuity between transfer control unit harness connector E142 terminals 3, 6, E143 terminal 45 and ground.

      Continuity should exist. 

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

    OK or NG 

    OK: GO TO 3.

    NG: Repair open circuit or short to ground or short to power in harness or connectors.

    Fig 3: Checking Continuity Between Transfer Control Unit Connector E142, E143 And Ground
    G04901468
  3. CHECK ACTUATOR MOTOR POWER SUPPLY CIRCUIT 
    1. Turn ignition switch "OFF". (Stay for at least 5 seconds.)
    2. Remove transfer shift high relay and transfer shift low relay. Refer to "LOCATION OF ELECTRICAL PARTS ".
    3. Check voltage between transfer shift high relay harness connector E46 terminal 5 (A), transfer shift low relay harness connector E47 terminal 5 (B) and ground.
      TERMINALS VOLTAGE CHART

      Connector Terminal Voltage (Approx.)
      E46 5 - Ground Battery voltage
      E47 5 - Ground
      Fig 4: Checking Voltage Between Transfer Shift High Relay Connector E46 And Ground
      G04901491
    4. Turn ignition switch "ON". (Do not start engine.)
    5. Check voltage between transfer shift high relay harness connector E46 terminal 5 (A), transfer shift low relay harness connector E47 terminal 5 (B) and ground.
      TERMINALS VOLTAGE CHART

      Connector Terminal Voltage (Approx.)
      E46 5 - Ground Battery voltage
      E47 5 - Ground
      Fig 5: Checking Voltage Between Transfer Shift High Relay Connector E46 And Ground
      G04901492

    OK or NG 

    OK: GO TO 4.

    NG: Check the following. If any items are damaged, repair or replace damaged parts.

    • 20A fuse No. 57 located in the fuse and relay box. Refer to "POWER SUPPLY ROUTING CIRCUIT ".
    • Harness for short or open between battery, transfer shift high relay harness connector E46 terminal 5 and transfer shift low relay harness connector E47 terminal 5.
  4. CHECK HARNESS BETWEEN TRANSFER CONTROL UNIT AND TRANSFER SHIFT RELAY 
    1. Turn ignition switch "OFF". (Stay for at least 5 seconds.)
    2. Disconnect transfer control unit harness connector and transfer control device (actuator motor) harness connector.
    3. Remove transfer shift high relay and transfer shift low relay. Refer to "LOCATION OF ELECTRICAL PARTS ".
    4. Check continuity between the following terminals.
      • Transfer control unit harness connector E143 terminal 33 (A) and transfer shift high relay harness connector E46 terminal 3 (B).
      • Transfer control unit harness connector E143 terminal 42 (A) and transfer shift low relay harness connector E47 terminal 3 (C).

        Continuity should exist. 

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

    OK or NG 

    OK: GO TO 5.

    NG: Repair or replace damaged parts.

    Fig 6: Checking Continuity Between Transfer Control Unit And Transfer Shift High Relay
    G04901497
  5. CHECK TRANSFER SHIFT RELAY GROUND CIRCUIT 
    1. Turn ignition switch "OFF". (Stay for at least 5 seconds.)
    2. Remove transfer shift high relay and transfer shift low relay.
    3. Check continuity between transfer shift high relay harness connector E46 terminals 2, 4 (A), transfer shift low relay harness connector E47 terminals 2, 4 (B) and ground.

      Continuity should exist. 

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

    OK or NG 

    OK: GO TO 6.

    NG: Repair open circuit or short to ground or short to power in harness or connectors.

    Fig 7: Checking Continuity Between Transfer Shift High Relay Connector E46 And Ground
    G04901493
  6. CHECK TRANSFER CONTROL UNIT 

    Check transfer control unit input/output signal. Refer to "TRANSFER CONTROL UNIT INPUT/OUTPUT SIGNAL REFERENCE VALUES ".

    OK or NG 

    OK-1: With CONSULT-II: GO TO 7.

    OK-2: Without CONSULT-II: GO TO  8.

    NG: Check transfer control unit pin terminals for damage or loose connection with harness connector. If any items are damaged, repair or replace damaged parts.

  7. PERFORM SELF-DIAGNOSIS (WITH CONSULT-II) 

    With CONSULT-II 

    1. Turn ignition switch "ON". (Do not start engine.)
    2. Select "SELF-DIAG RESULTS" mode for "ALL MODE AWD/4WD" with CONSULT-II.
    3. Touch "ERASE".
    4. Turn ignition switch "OFF" and wait at least 10 seconds.
    5. Perform the self-diagnosis again.

    Is the "SHIFT ACT CIR [P1819]" displayed? 

    Yes: Replace transfer control unit. Refer to "REMOVAL AND INSTALLATION ".

    No: Inspection End.

  8. PERFORM SELF-DIAGNOSIS (WITHOUT CONSULT-II) 

    Without CONSULT-II 

    1. Perform the self-diagnosis and then erase self-diagnostic results. Refer to "SELF-DIAGNOSTIC PROCEDURE (WITHOUT CONSULT-II) " and "ERASE SELF-DIAGNOSIS ".
    2. Perform the self-diagnosis again.

    Do the self-diagnostic results indicate transfer control device? 

    Yes: Replace transfer control unit. Refer to "REMOVAL AND INSTALLATION ".

    No: Inspection End.

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