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Home >> Nissan-Datsun >> 2008 >> Sentra SL >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Engine Control System - Component Testing (MR20DE) >> Refrigerant Pressure Sensor >> Diagnostic Procedure
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Diagnostic Procedure

  1. CHECK REFRIGERANT PRESSURE SENSOR OVERALL FUNCTION 
    1. Start engine and warm it up to normal operating temperature.
    2. Turn A/C switch and blower fan switch ON.
    3. Check voltage between ECM terminal 41 and ground with CONSULT-III or tester.

      Voltage: 1.0 - 4.0V 

    OK or NG 

    OK: INSPECTION END 

    NG: GO TO 2.

    Fig 1: Checking Voltage Between ECM Terminal 41 And Ground
    G04925656Courtesy of NISSAN MOTOR CO., U.S.A.
  2. CHECK GROUND CONNECTIONS 
    1. Turn A/C switch and blower fan switch OFF.
    2. Stop engine and turn ignition switch OFF.
    3. Loosen and retighten ground screws on the body.

      Refer to "GROUND INSPECTION ".

      • <=: Vehicle front
      • Body ground (1)

    OK or NG 

    OK: GO TO 3.

    NG: Repair or replace ground connections.

    Fig 2: Identifying Body Ground
    G04925191Courtesy of NISSAN MOTOR CO., U.S.A.
  3. CHECK REFRIGERANT PRESSURE SENSOR POWER SUPPLY CIRCUIT 
    1. Disconnect refrigerant pressure sensor (1) harness connector.
    2. Turn ignition switch ON.
      Fig 3: Identifying Refrigerant Pressure Sensor
      G04925653Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Check voltage between refrigerant pressure sensor terminal 3 and ground with CONSULT-III or tester.

      Voltage: Approximately 5V 

    OK or NG 

    OK: GO TO  5.

    NG: GO TO 4.

    Fig 4: Checking Voltage Between Refrigerant Pressure Sensor Terminal 3 And Ground
    G04894984Courtesy of NISSAN MOTOR CO., U.S.A.
  4. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors E3, F2
    • Harness for open or short between refrigerant pressure sensor and ECM

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

  5. CHECK REFRIGERANT PRESSURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT 
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Check harness continuity between refrigerant pressure sensor terminal 1 and ECM terminal 48.

      Refer to WIRING DIAGRAM .

      Continuity should exist. 

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

    OK or NG 

    OK: GO TO  7.

    NG: GO TO 6.

  6. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors E3, F2
    • Harness for open or short between refrigerant pressure sensor and ECM

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

  7. CHECK REFRIGERANT PRESSURE SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT 
    1. Check harness continuity between refrigerant pressure sensor terminal 2 and ECM terminal 41.

      Refer to WIRING DIAGRAM .

      Continuity should exist. 

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

    OK or NG 

    OK: GO TO  9.

    NG: GO TO 8.

  8. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors E3, F2
    • Harness for open or short between refrigerant pressure sensor and ECM

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

  9. CHECK INTERMITTENT INCIDENT 

    Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    OK or NG 

    OK: Replace refrigerant pressure sensor.

    NG: Repair or replace.