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Home >> Infiniti >> 2012 >> QX56 AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - DTCS P0137 To P0463 >> DTC P0191: FRP Sensor >> Diagnosis Procedure

Diagnosis Procedure

NOTE: Turning the ignition switch ON with FRP sensor harness connector disconnected causes ECM to detect DTC P0190. Be sure to erase the DTC when the diagnosis procedure.
  1. CHECK FRP SENSOR POWER SUPPLY-I
    1. Turn ignition switch OFF.
    2. Disconnect FRP sensor connector.
    3. Turn ignition switch ON.
    4. Check the voltage between FRP sensor harness connector terminals.
    FRP sensor Voltage (Approx.)
    Connector + -
    terminal
    F26 1 3 5 V

    Inspection result normal? 

    YES: GO TO  6.

    NO: GO TO 2.

  2. CHECK FRP SENSOR POWER SUPPLY-I

    Check the voltage between FRP sensor harness connector and the ground.

    + - Voltage (Approx.)
    FRP sensor
    Connector Terminal
    F26 1 Ground 5 V

    Is inspection result normal? 

    YES: GO TO  4.

    NO: GO TO 3.

  3. CHECK SENSOR POWER SUPPLY CIRCUIT
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Check harness connector for short to power and short to ground, between the following terminals.
    ECM Sensor
    Connector Terminal Name Connector Terminal
    F111 27 Low fuel pressure sensor F25 3
    Power steering pressure sensor F35 1
    Cooling fan speed sensor F39 2
    28 FRP sensor F26 1

    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 FRP SENSOR GROUND CIRCUIT
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Check the continuity between FRP sensor harness connector and ECM harness connector.
    + - Continuity
    FRP sensor ECM
    Connector Terminal Connector Terminal
    F26 3 F111 40 Existed

    Is inspection result normal? 

    YES: GO TO 5.

    NO: Repair or replace error-detected parts.

  5. CHECK ECM GROUND CIRCUIT

    Check the continuity between ECM harness connector and the ground.

    ECM Ground Continuity
    Connector Terminal
    F111 5 Ground Existed
    E80 114
    115
    174
    175

    Is inspection result normal? 

    YES: Check intermittent incident. Refer to "INTERMITTENT INCIDENT ".

    NO: Repair or replace error-detected parts.

  6. CHECK FRP SENSOR SIGNAL CIRCUIT
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Check the continuity between FRP sensor harness connector and ECM harness connector.
      + - Continuity
      FRP sensor ECM
      Connector Terminal Connector Terminal
      F26 2 F111 31 Existed
    4. Also check harness for short to ground and to power.

    Is inspection result normal? 

    YES: GO TO 7.

    NO: Repair or replace error-detected parts.

  7. CHECK FRP SENSOR

    Refer to "COMPONENT INSPECTION (FUEL RAIL PRESSURE SENSOR) ".

    Is inspection result normal? 

    YES: Check intermittent incident. Refer to "INTERMITTENT INCIDENT ".

    NO: Repair or replace error-detected parts.

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