Diagnostic Procedure For Magnet Clutch

WARNING: This page is about a different car, the 2008 Nissan Maxima. 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 Circuit Diagram

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

CHECK INTAKE SENSOR CIRCUIT
Check intake sensor. Refer to "FUNCTION CONFIRMATION PROCEDURE ".

OK or NG

OK: GO TO 2.

NG: Malfunctioning intake 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-III
  GO TO 5.
- WITHOUT !CONSULT-III
  GO TO 6.
NO: Check 10A fuse (No. 33, 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 E124 terminal 33 and compressor harness connector F3 terminal 1.
  33 - 1: Continuity should exist .
Fig 2: Checking Continuity Between IPDM E/R Connector E124 Terminal 33 And Compressor Connector F3 Terminal 1
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG

OK: GO TO 4.

NG: Repair harness or connector.
CHECK MAGNET CLUTCH OPERATION
Check for operation sound when applying battery voltage direct current to terminal.

Fig 3: Checking Magnet Clutch Operation
Courtesy of NISSAN MOTOR CO., U.S.A.

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 ".
CHECK BCM INPUT (COMPRESSOR ON) SIGNAL
Check compressor ON/OFF signal. Refer to "CONSULT-III FUNCTION (BCM) ".

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.
CHECK CIRCUIT CONTINUITY BETWEEN BCM AND UNIFIED METER AND A/C AMP .
1. Turn ignition switch OFF.
2. Disconnect BCM connector and unified meter and A/C amp. connector.
3. Check continuity between BCM harness connector M18 terminal 27 and unified meter and A/C amp. harness connector M89 terminal 42.
  27 - 42: Continuity should exist .
Fig 4: Checking Continuity Between BCM And Unified Meter And A/C Amp. Connector Terminal
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG

OK: GO TO 7.

NG: Repair harness or connector.

CHECK VOLTAGE FOR UNIFIED METER AND A/C AMP. (COMPRESSOR ON SIGNAL)

Reconnect BCM connector and unified meter and A/C amp. connector.
Turn ignition switch ON.

Check voltage between unified meter and A/C amp. harness connector M89 terminal 42 and ground.

VOLTAGE FOR UNIFIED METER AND A/C AMP. (COMPRESSOR ON SIGNAL)

Terminals			Condition	Voltage (Approx.)
(+)		(-)
Unified meter and A/C amp. connector	Terminal No.	(-)
M89	42	Ground	A/C switch: ON	0V
M89	42	Ground	A/C switch: OFF	5V

Fig 5: Checking Voltage Between Unified Meter And A/C Amp. Harness Connector M89 Terminal 42 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 unified meter and A/C amp. Refer to "UNIFIED METER AND A/C AMP .".

NG-2: If the voltage is approx. 0V when A/C switch is OFF: Replace BCM. Refer to "BCM ".

CHECK REFRIGERANT PRESSURE SENSOR

WITH CONSULT-III

Start engine.
Check voltage of refrigerant pressure sensor. Refer to "CONSULT-III FUNCTION (BCM) ".

WITHOUT CONSULT-III

Start engine.
Check voltage between ECM harness connector F54 terminal 70 and ground.

REFRIGERANT PRESSURE SENSOR

Terminals			Condition	Voltage (Approx.)
(+)		(-)
ECM connector	Terminal No.	(-)
F54	70	Ground	A/C switch: ON	3.60 - 3.88V

OK or NG

OK:

WITH CONSULT-III
GO TO 9.
WITHOUT CONSULT-III
GO TO 10.

NG: Refer to "REFRIGERANT PRESSURE SENSOR ".

CHECK BCM INPUT (FAN ON) SIGNAL
Check FAN ON/OFF signal. Refer to "CONSULT-III FUNCTION (BCM) ".

FAN CONTROL SWITCH ON: FAN ON SIG ON

FAN CONTROL SWITCH OFF: FAN ON SIG OFF

OK or NG

OK: GO TO 12.

NG: GO TO 10.
CHECK CIRCUIT CONTINUITY BETWEEN BCM AND UNIFIED METER AND A/C AMP .
1. Turn ignition switch OFF.
2. Disconnect BCM connector and unified meter and A/C amp. connector.
3. Check continuity between BCM harness connector M18 (A) terminal 28 and unified meter and A/C amp. harness connector M89 (B) terminal 57.
  28 - 57: Continuity should exist .
Fig 6: Checking Continuity Between BCM And Unified Meter And A/C Amp. Connector Terminal
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG

OK: GO TO 11.

NG: Repair harness or connector.

CHECK VOLTAGE FOR UNIFIED METER AND A/C AMP. (FAN ON SIGNAL)

Reconnect BCM connector and unified meter and A/C amp. connector.
Turn ignition switch ON.

Check voltage between unified meter and A/C amp. harness connector M89 terminal 57 and ground.

VOLTAGE FOR UNIFIED METER AND A/C AMP. (FAN ON SIGNAL)

Terminals			Condition	Voltage (Approx.)
(+)		(-)
Unified meter and A/C amp. connector	Terminal No.	(-)
M89	57	Ground	A/C switch: ON Blower motor operates	0V
M89	57	Ground	A/C switch: OFF	5V

Fig 7: Checking Voltage Between Unified Meter And A/C Amp. Harness Connector M89 Terminal 57 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 unified meter and A/C amp. "UNIFIED METER AND A/C AMP .".

NG-2: If the voltage is approx. 0V when blower motor is OFF: Replace BCM. Refer to "BCM ".

CHECK CAN COMMUNICATION
Check CAN communication. Refer to "TROUBLE DIAGNOSIS ".
- BCM - ECM
- ECM - IPDM E/R
- ECM - Unified meter and A/C amp.
OK or NG

OK: Inspection End

NG: Repair or replace malfunctioning part(s).