Diagnostic Procedure For Magnet Clutch

WARNING: This page is about a different car, the 2005 Infiniti QX56. However, it is still accessible from the selected car via links, so may be relevant.

SYMPTOM: Magnet clutch does not engage when A/C switch is ON.

Fig 1: Diagnostic Procedure For Magnet Clutch

Courtesy of NISSAN MOTOR CO., U.S.A.

CHECK INTAKE AND AMBIENT SENSOR CIRCUITS
Check intake and ambient sensors. Refer to "A/C SYSTEM SELF-DIAGNOSIS FUNCTION ".

OK or NG
- OK: GO TO 2.
- NG:
  - Malfunctioning intake sensor. Refer to "INTAKE SENSOR CIRCUIT ".
  - Malfunctioning ambient sensor. Refer to "INTAKE SENSOR CIRCUIT ".
PERFORM AUTO ACTIVE TEST
Refer to "AUTO ACTIVE TEST ".

Does magnet clutch operate?

YES or NO
- YES:
  - WITH CONSULT-II
    GO TO 5.
  - WITHOUT CONSULT-II
    GO TO 6.
- NO: Check 10A fuse (No. 42, located in IPDM E/R), and GO TO 3.
CHECK CIRCUIT CONTINUITY BETWEEN IPDM E/R AND COMPRESSOR
1. Turn ignition switch OFF.
2. Disconnect IPDM E/R connector and compressor (magnet clutch) connector.
3. Check continuity between IPDM E/R harness connector E119 terminal 11 (Y/B) and compressor harness connector F3 terminal 1 (Y/B).
  - 11 - 1: Continuity should exist.
OK or NG
- OK: GO TO 4.
- NG: Repair harness or connector.
Fig 2: Checking Continuity Between IPDM E/R Harness Connector E119 Terminal 11 And Compressor Harness Connector F3 Terminal 1
Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK MAGNET CLUTCH CIRCUIT
Check for operation sound when applying battery voltage direct current to terminal.

OK or NG
- OK: Replace IPDM E/R. Refer to "REMOVAL AND INSTALLATION OF IPDM E/R ".
- NG: Replace magnet clutch. Refer to "REMOVAL AND INSTALLATION FOR COMPRESSOR CLUTCH .
Fig 3: Applying Battery Voltage Direct Current To Terminal
Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK BCM INPUT (COMPRESSOR ON) SIGNAL
Check compressor ON/OFF signal. Refer to "CONSULT-II FUNCTION (HVAC) ".
- A/C SW ON: COMP ON SIG ON
- A/C SW OFF: COMP ON SIG OFF
OK or NG
- OK: GO TO 8.
- NG: GO TO 6.
Fig 4: Identifying "COMP ON SIG ON"
Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK CIRCUIT CONTINUITY BETWEEN BCM AND FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Disconnect BCM connector and front air control connector.
3. Check continuity between BCM harness connector M18 terminal 27 (W/R) and front air control harness connector M49 terminal 12 (W/R).
  - 27 - 12 Continuity should exist.
OK or NG
- OK: GO TO 7.
- NG: Repair harness or connector.
Fig 5: Checking Continuity Between BCM Harness Connector M18 Terminal 27 And Front Air Control Harness Connector M49 Terminal 12
Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK VOLTAGE FOR FRONT AIR CONTROL (COMPRESSOR ON SIGNAL)
1. Reconnect BCM connector and front air control connector.
2. Turn ignition switch ON.
3. Check voltage between front air control harness connector M49 terminal 12 (W/R) and ground.
  
  Fig 6: Front Air Control Harness Connector M49 Terminal 12 And Ground Voltage Specifications
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Fig 7: Checking Voltage Between Front Air Control Harness Connector M49 Terminal 12 And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
- OK: GO TO 8.
- NG-1: If the voltage is approx. 5V when A/C switch is ON, replace front air control. Refer to "FRONT AIR CONTROL ".
- NG-2: If the voltage is approx. 0V when A/C switch is OFF, replace BCM. Refer to "REMOVAL AND INSTALLATION OF BCM ".
CHECK REFRIGERANT PRESSURE SENSOR
WITH CONSULT-II
1. Start engine.
2. Check voltage of refrigerant pressure sensor. Refer to "CONSULT-II FUNCTION (HVAC) ".
WITHOUT CONSULT-II
1. Start engine.
2. Check voltage between ECM harness connector F54 terminal 70 (B/W) and ground.
  
  Fig 8: ECM Harness Connector F54 Terminal 70 And Ground Voltage Specifications
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Fig 9: Checking Voltage Between ECM Harness Connector F54 Terminal 70 And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
- OK:
  - WITH CONSULT-II
    GO TO 9.
  - WITHOUT CONSULT-II
    GO TO 10.
- NG: Refer to "REFRIGERANT PRESSURE SENSOR ".
CHECK BCM INPUT (FAN ON) SIGNAL
Check FAN ON/OFF signal. Refer to "CONSULT-II FUNCTION (HVAC) ".
- FRONT BLOWER CONTROL: FAN ON SIG ON
  DIAL ON
- FRONT BLOWER CONTROL: FAN ON SIG OFF
  DIAL OFF
OK or NG
- OK: GO TO 12.
- NG: GO TO 10.
Fig 10: Identifying "FAN ON SIG ON"
Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK CIRCUIT CONTINUITY BETWEEN BCM AND FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Disconnect BCM connector and front air control connector.
3. Check continuity between BCM harness connector M18 terminal 28 (L/R) and front air control harness connector M49 terminal 10 (L/R).
  - 28 - 10 Continuity should exist.
OK or NG
- OK: GO TO 11.
- NG: Repair harness or connector.
Fig 11: Checking Continuity Between BCM Harness Connector M18 Terminal 28 And Front Air Control Harness Connector M49 Terminal 10
Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK VOLTAGE FOR FRONT AIR CONTROL (FAN ON SIGNAL)
1. Reconnect BCM connector and front air control connector.
2. Turn ignition switch ON.
3. Check voltage between front air control harness connector M49 terminal 10 (L/R) and ground.
  
  Fig 12: Front Air Control Harness Connector M49 Terminal 10 And Ground Voltage Specifications
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Fig 13: Checking Voltage Between Front Air Control Harness Connector M49 Terminal 10 And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
- OK: GO TO 12.
- NG-1: If the voltage is approx. 5V when blower motor is ON, replace front air control. Refer to "FRONT AIR CONTROL ".
- NG-2: If the voltage is approx. 0V when blower motor is OFF, replace BCM. Refer to "REMOVAL AND INSTALLATION OF BCM ".
CHECK CAN COMMUNICATION
Check CAN communication. Refer to "CAN COMMUNICATION ".
- BCM - ECM
- ECM - IPDM E/R
- ECM - Front air control
OK or NG
- OK: Inspection End.
- NG: Repair or replace malfunctioning part(s).