Diagnostic Procedure

WARNING: This page is about a different car, the 2003 Nissan Altima. 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: Magnet Clutch Diagnostic Procedure

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

CHECK CIRCUIT CONTINUITY BETWEEN A/C RELAY IN IPDM E/R AND COMPRESSOR

Fig 2: Checking Circuit Continuity Between A/C Relay In IPDM E/R And Compressor (1 Of 2)
Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 3: Checking Circuit Continuity Between A/C Relay In IPDM E/R And Compressor (2 Of 2)
Courtesy of NISSAN MOTOR CO., U.S.A.

If OK, check harness for short.

OK or NG
1. OK: GO TO 2.
2. NG: Repair harness or connector.
CHECK POWER SUPPLY FOR COMPRESSOR
Disconnect compressor harness connector.

Fig 4: Checking Compressor Power Supply (1 Of 2)
Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 5: Checking Compressor Power Supply (2 Of 2)
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG
1. OK: Check magnet clutch coil.
  1. If NG, replace magnet clutch. Refer to "REMOVAL AND INSTALLATION FOR COMPRESSOR CLUTCH "
  2. It OK, check compressor mourning points for looseness or corrosion ana repair as necessary.
2. NG: GO TO 3.
CHECK A/C RELAY IN IPDM E/R

Fig 6: Checking A/C Relay In IPDM E/R (1 Of 2)
Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 7: Checking A/C Relay In IPDM E/R (2 Of 2)
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG
1. OK: GO TO 4.
2. NG:
  - Disconnect BCM harness connector M18.
  - GO TO 8.
CHECK VOLTAGE FOR BCM

Fig 8: Checking BCM Voltage (1 Of 2)
Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 9: Checking BCM Voltage (2 Of 2)
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG
1. OK: GO TO 5.
2. NG: Check BCM.
CHECK REFRIGERANT PRESSURE SENSOR INPUT SIGNAL

Fig 10: Checking Refrigerant Pressure Sensor Input Signal (1 Of 2)
Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 11: Checking Refrigerant Pressure Sensor Input Signal (2 Of 2)
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG
1. OK: GO TO 6.
2. NG:
  1. Repair harness or connector.
  2. GO TO "FUNCTION CONFIRMATION PROCEDURE " and perform self-diagnosis STEP-4.
    Confirm that magnet clutch operation is normal.
CHECK REFRIGERANT PRESSURE SENSOR
Refer to "REFRIGERANT PRESSURE SENSOR ".

OK or NG
1. OK: GO TO 7.
2. NG: Replace refrigerant pressure sensor.
CHECK VOLTAGE FOR THERMO CONTROL AMP.

Fig 12: Checking Thermo Control Amp Voltage (1 Of 2)
Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 13: Checking Thermo Control Amp Voltage (2 Of 2)
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG
1. OK: GO TO 8.
2. NG:
  - Check power supply circuit and 15A fuse [No. 12 located at fuse block (J/B)]. Refer to "POWER SUPPLY ROUTING CIRCUIT "
  - If OK, check for open circuit in wiring harness. Repair or replace as necessary.
  - If NG, replace fuse and check wiring harness for short circuit. Repair or replace as necessary.
CHECK POWER SUPPLY FOR THERMO CONTROL AMP.

Fig 14: Checking Thermo Control Amp Power Supply (1 Of 2)
Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 15: Checking Thermo Control Amp Power Supply (2 Of 2)
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG
1. OK: GO TO 9.
2. NG: Repair or replace thermo control amp.
CHECK THERMO CONTROL AMP. OPERATION

Fig 16: Checking Thermo Control Amp. Operation (1 Of 2)
Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 17: Checking Thermo Control Amp. Operation (2 Of 2)
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG
1. OK: GO TO 10.
2. NG: Replace thermo control amp.
CHECK THERMO CONTROL AMP.
Refer to "THERMO CONTROL AMP. "

OK or NG
1. OK: GO TO 11.
2. NG: Repair harness or connector.
CHECK CIRCUIT CONTINUITY BETWEEN THERMO CONTROL AMP. AND AUTO AMP.

Fig 18: Checking Circuit Continuity Between Thermo Control AMP. And Auto AMP. (1 Of 2)
Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 19: Checking Circuit Continuity Between Thermo Control AMP. And Auto AMP. (2 Of 2)
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG
1. OK: GO TO 12.
2. NG: Repair harness or connector.
CHECK COMPRESSOR ON SIGNAL
When compressor is ON or OFF, check voltage between auto amp. and ground.

Fig 20: Checking Compressor On Signal (1 Of 2)
Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 21: Checking Compressor On Signal (2 Of 2)
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG
1. OK: GO TO 13.
2. NG:
  - When compressor is ON and voltage is not approx. 0V, replace auto amp.
  - When compressor is OFF and voltage is not approx. 5V, BCM is malfunctioning.
CHECK CAN COMMUNICATION CIRCUITS
Check CAN communication circuits between BCM to ECM and between ECM to IPDM E/R. Refer to "CAN COMMUNICATION ".

OK or NG
1. OK: ECM malfunctioning.
2. NG: Repair or replace component based on the result of diagnosis.