LEMON Manuals: Even more car manuals for everyone
Home >> Infiniti >> 2024 >> QX55 Essential >> Repair and Diagnosis >> Engine Performance >> Testing & Diagnosis >> Engine Control System (DTC/Circuit Diagnosis) (3 Of 4) >> DTC/Circuit Diagnosis >> P0643 Sensor Power Supply >> Diagnosis Procedure

Diagnosis Procedure

  1. CHECK ACCELERATOR PEDAL POSITION SENSOR 1 POWER SUPPLY CIRCUIT 
    1. Disconnect accelerator pedal position (APP) sensor 1 harness connector.
    2. Turn ignition switch ON.
    3. Check the voltage between APP sensor 1 harness connector and ground.
      + - Voltage(Approx.)
      APP sensor 1
      Connector Terminal
      E20 4 Ground 5 V

    Is the inspection result normal?

    >>

    Proceed to Component Inspection .

    >>

    GO TO 2.

  2. CHECK SENSOR POWER SUPPLY CIRCUITS 

    Check harness for short to power and short to ground, between the following terminals.

    ECM Sensor
    Connector Terminal Name Connector Terminal
    F51 21 Crankshaft position sensor F17 1
    28 Exhaust camshaft position sensor F45 1
    54 Manifold absolute pressure sensor F67 1
    Battery current sensor E33 1
    Electric wastegate control actuator F70 5
    F52 83 Intake manifold runner control valve position sensor F20 1
    Multi-way control valve F98 4
    E16 156 APP sensor 1 E20 4

    Is the inspection result normal?

    >>

    GO TO 3.

    >>

    Repair or replace malfunctioning part.

  3. CHECK COMPONENTS 

    Check the following.

    Is the inspection result normal?

    >>

    INSPECTION END

    >>

    Repair or replace malfunctioning part.