Diagnostic Procedure

WARNING: This page is about a different car, the 2007 Nissan Quest. However, it is still accessible from the selected car via links, so may be relevant.

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 70 and ground with CONSULT- II or tester.
  Voltage: 1.0 - 4.0V
OK or NG

OK: INSPECTION END

NG: GO TO 2.

Fig 1: Check Voltage Between ECM Terminal 70 And Ground
Courtesy of NISSAN NORTH AMERICA, INC.
CHECK GROUND CONNECTIONS
1. Stop engine.
2. Turn A/C switch and blower fan switch OFF
3. Loosen and retighten three ground screws on the body. Refer to "GROUND INSPECTION ".
  
  Fig 2: Identifying Ground Screws On Body
  Courtesy of NISSAN NORTH AMERICA, INC.
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 harness connector.
2. Turn ignition switch ON.
  
  Fig 3: Identifying Refrigerant Pressure Sensor Harness Connector
  Courtesy of NISSAN NORTH AMERICA, INC.
3. Check voltage between refrigerant pressure sensor terminal 1 and ground with CONSULT-II or tester.
  Voltage: Approximately 5V
OK or NG

OK: GO TO 5.

NG: GO TO 4.

Fig 4: Checking Voltage Between PSP Sensor Terminal 1 And Ground
Courtesy of NISSAN NORTH AMERICA, INC.
DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors E19, F33
- Harness for open or short between ECM and refrigerant pressure sensor
: Repair 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 3 and ECM terminal 67.
  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 E19, F33
- Harness for open or short between ECM and refrigerant pressure sensor
: 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 ECM terminal 70 and refrigerant pressure sensor terminal 2. 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 E19, F33
- Harness for open or short between ECM and refrigerant pressure sensor
: 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.