Infiniti Q45. Manual - part 123

 

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Infiniti Q45. Manual - part 123

 

 

TROUBLE DIAGNOSIS

ATC-87

C

D

E

F

G

H

I

K

L

M

A

B

ATC

SYSTEM DESCRIPTION

Auto amp. controls compressor operation by ambient temperature, intake air temperature and signal from
ECM.

Low Temperature Protection Control

Auto amp. will turn compressor ON or OFF as determined by a signal detected by ambient sensor and intake
sensor.
When ambient temperature is higher than 

2

°

C (28

°

F), the compres-

sor turns ON. The compressor turns OFF when ambient temperature
is lower than 

5

°

C (23

°

F).

When intake air temperature is higher than 1

°

C (34

°

F), the compres-

sor turns ON. The compressor turns OFF when intake air tempera-
ture is lower than 

5

°

C (23

°

F).

DIAGNOSIS PROCEDURE FOR MAGNET CLUTCH

SYMPTOM: Magnet clutch does not engage when AUTO switch is ON.

RHA094GB

SJIA0267E

RJIA3188E

ATC-88

TROUBLE DIAGNOSIS

1. 

CHECK POWER SUPPLY FOR COMPRESSOR

1.

Disconnect compressor connector.

2.

Start engine and AUTO switch ON.

3.

Check voltage between compressor (magnet clutch) harness
connector F2 terminal 1 and ground.

OK or NG

OK

>> GO TO 2.

NG

>> GO TO 3.

2. 

CHECK MAGNET CLUTCH CIRCUIT

Check for operation sound when applying battery voltage direct cur-
rent to terminal.
OK or NG

OK

>> 1. Repair harness or connector.

2. Go to self-diagnosis 

ATC-54, "FUNCTION CONFIR-

MATION PROCEDURE"

  and perform self-diagnosis

STEP-4. Confirm that magnet clutch operation is nor-
mal.

NG

>> 1. Replace magnet clutch. Refer to 

ATC-150, "Removal

and Installation of Compressor Clutch"

 .

2. Go to self-diagnosis 

ATC-54, "FUNCTION CONFIR-

MATION PROCEDURE"

  and perform self-diagnosis STEP-4. Confirm that magnet clutch oper-

ation is normal.

3. 

CHECK CIRCUIT CONTINUITY BETWEEN A/C RELAY AND COMPRESSOR

1.

Turn ignition switch OFF.

2.

Disconnect A/C relay.

3.

Check continuity between compressor (magnet clutch) harness
connector F2 terminal 1 and A/C relay harness connector E3-2
terminal 3.

OK or NG

OK

>> Check harness for short. And GO TO 4.

NG

>> Repair harness or connector.

1 – Ground

: Battery voltage

RJIA3035E

RJIA2005E

1 – 3

: Continuity should exist.

RJIA3036E

TROUBLE DIAGNOSIS

ATC-89

C

D

E

F

G

H

I

K

L

M

A

B

ATC

4. 

CHECK POWER SUPPLY FOR A/C RELAY

Check voltage between A/C relay harness connector E3-2 terminals
2, 5 and ground.

OK or NG

OK

>> GO TO 5.

NG

>> Check power supply circuit and 10 A fuse [No. 51 

located in the fuse, fusible link and relay block (J/B)]. 
Refer to 

PG-72, "FUSE, FUSIBLE LINK AND RELAY 

BLOCK (J/B)"

 .

If fuse is OK, check harness for open circuit. Repair or
replace if necessary.

If fuse is NG, replace fuse and check harness for short circuit. Repair or replace if necessary.

5. 

CHECK A/C RELAY AFTER DISCONNECTING IT

Refer to 

ATC-92, "A/C Relay"

 .

OK or NG

OK

>> GO TO 6.

NG

>> 1. Replace A/C relay.

2. Go to self-diagnosis 

ATC-54, "FUNCTION CONFIRMATION PROCEDURE"

  and perform self-

diagnosis STEP-4. Confirm that magnet clutch operation is usual.

6. 

CHECK COIL SIDE CIRCUIT OF A/C RELAY

1.

Reconnect A/C relay.

2.

Turn ignition switch OFF.

3.

Check voltage between ECM harness connector F101 terminal
105 and ground.

OK or NG

OK

>> GO TO 8.

NG

>> GO TO 7.

7. 

CHECK CIRCUIT CONTINUITY BETWEEN ECM AND A/C RELAY

1.

Turn ignition switch OFF.

2.

Disconnect A/C relay and ECM connector.

3.

Check continuity between ECM harness connector F101 termi-
nal 105 and A/C relay harness connector E3-2 terminal 1.

OK or NG

OK

>> Replace A/C relay.

NG

>> Repair harness or connector.

2, 5 – Ground

: Battery voltage

RJIA3037E

105 – Ground

: Battery voltage

RJIA3189E

105 – 1

: Continuity should exist.

RJIA3190E

ATC-90

TROUBLE DIAGNOSIS

8. 

CHECK VOLTAGE FOR COMBINATION METER (FAN ON SIGNAL)

1.

Turn ignition switch ON.

2.

Check voltage between auto amp. harness connector M120 ter-
minal 29 and ground.

OK or NG

OK

>> GO TO 9.

NG

>> GO TO 12.

9. 

CHECK VOLTAGE FOR COMBINATION METER (COMPRESSOR ON SIGNAL)

Check voltage between auto amp. harness connector M120 terminal
22 and ground.

OK or NG

OK

>> GO TO 10.

NG

>> GO TO 13.

10. 

CHECK VOLTAGE FOR ECM (COMPRESSOR FEEDBACK SIGNAL)

1.

Start engine and AUTO switch ON.

2.

Check voltage between auto amp. harness connector M119 ter-
minal 18 and ground.

OK or NG

OK

>> GO TO 11.

NG

>> GO TO 14.

Terminals

Condition

Voltage

(+)

(

)

Auto amp. 

connector

Terminal No.

M120

29

Ground

AUTO SW: ON 
(Blower motor operates.)

Approx. 0 V

OFF SW: ON
(A/C system: OFF)

Approx. 5 V

RJIA3040E

Terminals

Condition

Voltage

(+)

(

)

Auto amp. 

connector

Terminal No.

M120

22 Ground

AUTO SW: ON
(Blower motor operates.)

Approx. 0 V

OFF SW: ON
(A/C system: OFF)

Approx. 5 V

RJIA3041E

Terminals

Condition

Voltage

(+)

(

)

Auto amp.

connector

Terminal No.

M119

18

Ground

AUTO SW: ON
(Blower motor oper-
ates.)

Approx. 0 V

AUTO SW: ON
(When refrigerant pres-
sure sensor connector 
is disconnected)

Approx. 5 V

RJIA3042E

 

 

 

 

 

 

 

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