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Home >> Infiniti >> 2021 >> QX80 Premium Select, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (DTCS) (3 Of 5) >> Engine (ECM) >> DTC P0550: PSP Sensor >> DTC Diagnosis Procedure

DTC Diagnosis Procedure

  1. CHECK POWER STEERING PRESSURE SENSOR POWER SUPPLY CIRCUIT-I 
    1. Turn ignition switch OFF.
    2. Disconnect power steering pressure (PSP) sensor harness connector.
    3. Turn ignition switch ON.
    4. Check the voltage between PSP sensor harness connector terminals.

      PSP sensor

      Voltage

      (Approx.)

      Connector

      +

      -

      terminal

      F35

      1

      3

      5 V

    Is the inspection result normal?

    YES

    GO TO 6.

    NO

    GO TO 2.

  2. CHECK POWER STEERING PRESSURE SENSOR POWER SUPPLY CIRCUIT-II 
    1. Check the voltage between PSP sensor harness connector and the ground.

      +

      -

      Voltage

      (Approx.)

      PSP sensor

      Connector

      terminal

      F35

      1

      Ground

      5 V

    Is inspection result normal?

    YES

    GO TO 4.

    NO

    GO TO 3.

  3. CHECK SENSOR POWER SUPPLY 3 CIRCUIT 

    Refer to Diagnosis Procedure .

    Is inspection result normal?

    YES

    Perform the trouble diagnosis for power supply circuit. Refer to Diagnosis Procedure .

    NO

    Repair or replace error-detected parts.

  4. CHECK PSP SENSOR GROUND CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Check the continuity between PSP sensor harness connector and ECM harness connector.

      +

      -

      Continuity

      PSP sensor

      ECM

      Connector

      Terminal

      Connector

      Terminal

      F35

      3

      F91

      13

      Existed

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

    Is the inspection result normal?

    YES

    GO TO 5.

    NO

    Repair or replace error-detected parts.

  5. CHECK ECM GROUND CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Check the continuity between ECM harness connector and the ground.

      +

      -

      Continuity

      ECM

      Connector

      Terminal

      E20

      147

      Ground

      Existed

      149

      152

    Is inspection result normal?

    YES

    Check intermittent incident. Refer to Inspection .

    NO

    Repair or replace error-detected parts.

  6. CHECK PSP SENSOR SIGNAL CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Check the continuity between PSP sensor harness connector and ECM harness connector.

      +

      -

      Continuity

      PSP sensor

      ECM

      Connector

      Terminal

      Connector

      Terminal

      F35

      2

      F91

      24

      Existed

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

    Is the inspection result normal?

    YES

    GO TO 7.

    NO

    Repair or replace error-detected parts.

  7. CHECK PSP SENSOR 

    Refer to Component Inspection .

    Is the inspection result normal?

    YES

    GO TO 8.

    NO

    Replace PSP sensor.

  8. CHECK INTERMITTENT INCIDENT 

    Refer to Inspection .

    INSPECTION END