Diagnostic Procedure

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 39 and ground with CONSULT-III or tester.
  Voltage: 1.0 - 4.0V
  
  Fig 1: Checking Voltage Between ECM Terminal 39 And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG

OK: INSPECTION END

NG: GO TO 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 ".
  
  Fig 2: Identifying Body Ground Connections
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG

OK: GO TO 3.

NG: Repair or replace ground connections.
CHECK REFRIGERANT PRESSURE SENSOR POWER SUPPLY CIRCUIT
1. Disconnect refrigerant pressure sensor (1) harness connector.
  - <= : Vehicle front
2. Turn ignition switch ON.
  
  Fig 3: Identifying Refrigerant Pressure Sensor
  Courtesy 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
  
  Fig 4: Checking Voltage Between Refrigerant Pressure Sensor Terminal 3 And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG

OK: GO TO 5.

NG: GO TO 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.
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 40.
  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.
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.
CHECK REFRIGERANT PRESSURE SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between refrigerant pressure sensor terminal 2 and ECM terminal 39.
  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.
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.
CHECK INTERMITTENT INCIDENT
Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

OK or NG

OK: Replace refrigerant pressure sensor.

NG: Repair or replace.