Infiniti FX35 / FX45. Manual - part 114

 

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Infiniti FX35 / FX45. Manual - part 114

 

 

ATC-52

< SERVICE INFORMATION >

TROUBLE DIAGNOSIS

If all operational checks are OK (symptom cannot be duplicated), go to Incident Simulation Tests in 

GI-25,

"How to Perform Efficient Diagnosis for an Electrical Incident"

 and perform tests as outlined to simulate driving

conditions environment. If symptom appears, refer to 

ATC-32, "How to Perform Trouble Diagnosis for Quick

and Accurate Repair"

 and perform applicable trouble diagnosis procedures.

Power Supply and Ground Circuit for Auto Amp

INFOID:0000000001328183

SYMPTOM: A/C system does not activate.

INSPECTION FLOW

COMPONENT DESCRIPTION

Unified Meter and A/C Amp. (Automatic Amplifier)

The unified meter and A/C amp. has a built-in microcomputer which
processes information sent from various sensors needed for air con-
ditioner operation. The air mix door motor, mode door motor, intake
door motor, blower motor and compressor are then controlled.
When the various switches and temperature control switch are oper-
ated, data is input to the unified meter and A/C amp. from the display
control unit using CAN communication. 
Self-diagnosis functions are also built into unified meter and A/C
amp. to provide quick check of malfunctions in the auto air condi-
tioner system.

Potentio Temperature Control (PTC)

*1

"DIAGNOSIS PROCEDURE FOR A/
C SYSTEM"

*2

ATC-50, "Operational Check"

*3

AV-79, "Unable to Operate System 
with A/C and AV Switch"

 (Without 

navigation system) or 

AV-127, "Un-

able to Operate System with A/C and 
AV Switch"

 (With navigation system)

SJIA1582E

SJIA1566E

TROUBLE DIAGNOSIS

ATC-53

< SERVICE INFORMATION >

C

D

E

F

G

H

I

K

L

M

A

B

ATC

N

O

P

The PTC is built into the A/C and AV switch. It can be set at an inter-
val of 0.5

°

C (1.0

°

F) in the 18

°

C (60

°

F) to 32

°

C (90

°

F) temperature

range by pressing temperature control switch. The set temperature
is displayed.

DIAGNOSIS PROCEDURE FOR A/C SYSTEM

SYMPTOM: A/C system does not activate.

1.

CHECK POWER SUPPLY CIRCUIT FOR UNIFIED METER AND A/C AMP.

1.

Disconnect unified meter and A/C amp. connector.

2.

Check voltage between unified meter and A/C amp. harness
connector M56 terminals 21, 22 and 35, unified meter and A/C
amp. harness connector M57 terminal 46 and ground.

OK or NG

OK

>> GO TO 2.

NG

>>

Check 10A and 15A fuses [Nos. 6, 10, 11, 12 and 19, located in the fuse block (J/B)]. Refer to

PG-77

.

• If fuses are OK, check harness for open circuit. Repair or replace if necessary.
• If fuses are NG, check harness for short circuit and replace fuse.

2.

CHECK GROUND CIRCUIT FOR UNIFIED METER AND A/C AMP.

1.

Turn ignition switch OFF.

SJIA1583E

RJIA1983E

Terminals

Ignition switch position

(+)

(

)

OFF

ACC

ON

Unified 

meter and 

A/C amp. 

connector

Terminal No.

M56

21

Ground

Battery volt-

age

Battery 
voltage

Battery 
voltage

M56

22

Approx. 0 V

Approx. 0 V

Battery 
voltage

M56

35

Approx. 0 V

Battery 
voltage

Battery 
voltage

M57

46

Approx. 0 V

Battery 
voltage

Battery 
voltage

RJIA1984E

ATC-54

< SERVICE INFORMATION >

TROUBLE DIAGNOSIS

2.

Check continuity between unified meter and A/C amp. harness
connector M56 terminal 29, 30 and ground.

OK or NG

OK

>> Replace unified meter and A/C amp.

NG

>> Repair harness or connector.

LAN System Circuit

INFOID:0000000001328184

SYMPTOM: Mode door motor, intake door motor and/or air mix door motor(s) does not operate normally.

DIAGNOSIS PROCEDURE FOR LAN CIRCUIT

1.

CHECK POWER SUPPLY FOR UNIFIED METER AND A/C AMP.

1.

Turn ignition switch ON.

2.

Check voltage between unified meter and A/C amp. harness
connector M57 terminal 54 and ground.

OK or NG

OK

>> GO TO 2.

NG

>> Replace unified meter and A/C amp.

2.

CHECK SIGNAL FOR UNIFIED METER AND A/C AMP. 

29, 30 – Ground

: Continuity should exist.

RJIA1985E

RJIA1775E

54 – Ground

: Battery voltage

RJIA1986E

TROUBLE DIAGNOSIS

ATC-55

< SERVICE INFORMATION >

C

D

E

F

G

H

I

K

L

M

A

B

ATC

N

O

P

Confirm A/C LAN signal between unified meter and A/C amp. har-
ness connector M57 terminal 43 and ground using an oscilloscope.

OK or NG

OK

>> GO TO 3.

NG

>> Replace unified meter and A/C amp.

3.

CHECK POWER SUPPLY FOR EACH DOOR MOTOR

Check voltage between each door motor harness connector terminal
1 and ground.

OK or NG

OK

>> GO TO 4.

NG

>> Repair harness or connector.

4.

CHECK SIGNAL FOR EACH DOOR MOTOR

Confirm A/C LAN signal between each door motor harness connec-
tor terminal 3 and ground using an oscilloscope.

OK or NG

OK

>> GO TO 5.

NG

>> Repair harness or connector.

5.

CHECK MOTOR GROUND CIRCUIT

1.

Turn ignition switch OFF.

2.

Disconnect each door motor connector.

Terminals

Voltage

(+)

(

)

Unified meter and A/

C amp. connector

Terminal No.

M57

43

Ground

RJIA1987E

SJIA1453J

1 – Ground

: Battery voltage

RJIA1988E

Door motor

Terminals

Voltage

(+)

(

)

Con-

nector

Terminal 

No.

Mode

M258

3

Ground

Air mix 
(Driver 
side)

M252

3

Air mix 
(Passen-
ger side)

M257

3

Intake

M253

3

RJIA1989E

SJIA1453J

 

 

 

 

 

 

 

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