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Home >> Nissan-Datsun >> 2004 >> Sentra Base, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - QG18DE >> 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 switch ON.
    3. Check voltage between ECM terminal 70 and ground with CONSULT-II or tester.
      1. Voltage: 1.0 - 4.0V 

    OK or NG 

    1. OK : INSPECTION END 
    2. NG : GO TO 2.
    Fig 1: Checking Voltage Between ECM Terminal 70 And Ground
    G00773427Courtesy of NISSAN MOTOR CO., U.S.A.
  2. CHECK REFRIGERANT PRESSURE SENSOR POWER SUPPLY CIRCUIT 
    1. Turn A/C switch and blower switch OFF.
    2. Stop engine.
    3. Disconnect refrigerant pressure sensor harness connector.
    4. Turn ignition switch ON.
      Fig 2: Disconnecting Refrigerant Pressure Sensor Harness Connector
      G00773428Courtesy of NISSAN MOTOR CO., U.S.A.
    5. Check voltage between refrigerant pressure sensor terminal 3 and ground with CONSULT-II or tester.
      1. Voltage: Approximately 5V 

    OK or NG 

    1. OK : GO TO  4.
    2. NG : GO TO 3.
    Fig 3: Checking Voltage Between Refrigerant Pressure Sensor Terminal 3 And Ground
    G00773429Courtesy of NISSAN MOTOR CO., U.S.A.
  3. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors E9, F47
    • Harness for open or short between ECM and refrigerant pressure sensor
      1. : Repair harness or connectors.
  4. CHECK REFRIGERANT PRESSURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT 
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Disconnect TCM harness connector.
    4. Check harness continuity between refrigerant pressure sensor terminal 1 and ECM terminal 67, TCM terminal 42.

      Refer to WIRING DIAGRAM .

      1. Continuity should exist. 
    5. Also check harness for short to ground and short to power.

    OK or NG 

    1. OK : GO TO  6.
    2. NG : GO TO 5.
  5. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors E10, F48
    • Harness for open or short between TCM and refrigerant pressure sensor
    • Harness for open or short between ECM and refrigerant pressure sensor
      1. : Repair open circuit or short to ground or short to power in harness or connectors.
  6. CHECK REFRIGERANT PRESSURE SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT 
    1. Check harness continuity between ECM terminal 70 and refrigerant pressure sensor terminal 2.
      1. Continuity should exist. 
    2. Also check harness for short to ground and short to power.

    OK or NG 

    1. OK : GO TO  8.
    2. NG : GO TO 7.
  7. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors E10, F48
    • Harness for open or short between ECM and refrigerant pressure sensor
      1. : Repair open circuit or short to ground or short to power in harness or connectors.
  8. CHECK REFRIGERANT PRESSURE SENSOR 

    Refer to REFRIGERANT PRESSURE SENSOR .

    OK or NG 

    1. OK : GO TO 9.
    2. NG : Replace refrigerant pressure sensor.
  9. CHECK INTERMITTENT INCIDENT 

    Refer to TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT .

    1. INSPECTION END 

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