air INFINITI FX35 2005 Service Manual

AIR CONDITIONER CONTROL ATC-39
C
D E
F
G H
I
K L
M A
B
AT C
Revision: 2005 July 2005 FX
CAN Communication System DescriptionAJS0014H
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN-H line, CAN-L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only. For details, refer to LAN-30,
"CAN Communication Unit" .

TROUBLE DIAGNOSIS ATC-41
C
D E
F
G H
I
K L
M A
B
AT C
Revision: 2005 July 2005 FX
DATA MONITOR
Operation Procedure
1. Touch “AIR CONDITIONER” on “SELECT TEST ITEM” screen.
2. Touch “DATA MONITOR” on “SELECT DIAG MODE” screen.
3. Touch either “ALL SIGNALS” or “SELECTION FROM MENU” on “DATA MONITOR” screen.
4. When “SELECTION FROM MENU” is selected, touch items to be monitored. When “ALL SIGNALS” is selected, all the items
will be monitored.
5. Touch “START”.
6. Touch “RECORD” while monitoring, then the status of the moni- tored item can be recorded. To stop recording, touch “STOP”.
Display Item List
SJIA0303E
BCIA0031E
All signals Monitors all the items.
Selection from menu Selects and monitors the individual item selected.
R J I A 1111 E
Monitor item name “operation or unit” Contents
IGN ON SW “ON/OFF” Displays “IGN position (ON)/OFF, ACC position (OFF)” status as judged from ignition switch signal.
FAN ON SIG “ON/OFF” Displays “FAN (ON)/FAN (OFF)” status as judged from blower fan motor switch signal.
AIR COND SW “ON/OFF” Displays “COMP (ON)/COMP (OFF)” status as judged from air conditioner switch signal.

ATC-42
TROUBLE DIAGNOSIS
Revision: 2005 July 2005 FX
How to Perform Trouble Diagnosis for Quick and Accurate RepairAJS0014K
WORK FLOW
SYMPTOM TABLE
*1 ATC-61, "Operational Check"
SHA900E
Symptom Reference Page
A/C system does not come on. Go to Trouble Diagnosis Procedure for A/C System. AT C - 6 3 , "
Power
Supply and Ground
Circuit for Auto
Amp."
A/C system cannot be controlled.
Go to Integrated Display System.

Go to Navigation System. AV-78, "
Trouble
Diagnosis Chart by
Symptom" (Without
navigation system) or AV-166, "
A/C
Screen Is Not
Shown (NAVI
Screen Is Shown)"
(With navigation
system)
Air outlet does not change. Go to Trouble Diagnosis Procedure for Mode Door Motor. (LAN) AT C - 7 0 , "
Mode
Door Motor Circuit"Mode door motor does not operate normally.
Discharge air temperature does not change. Go to Trouble Diagnosis Procedure for Air Mix Door Motor.
(LAN) ATC-73, "
Air Mix
Door Motor Circuit"Air mix door motor does not operate nor-
mally.
Intake door does not change. Go to Trouble Diagnosis Procedure for Intake Door Motor. (LAN) ATC-76, "
Intake
Door Motor Circuit"Intake door motor does not operate nor-
mally.
Blower motor operation is malfunctioning. Go to Trouble Diagnosis Procedure for Blower Motor. ATC-79, "
Blower
Motor Circuit"
Magnet clutch does not engage. Go to Trouble Diagnosis Procedure for Magnet Clutch.
ATC-84, "Magnet
Clutch Circuit"
Insufficient cooling Go to Trouble Diagnosis Procedure for Insufficient Cooling.
AT C - 9 1 , "
Insufficient
Cooling"
Go to Diagnosis Procedure for Insufficient Cooling. ATC-98, "
DIAGNO-
SIS PROCEDURE
FOR INSUFFI-
CIENT COOLING"
Insufficient heating Go to Trouble Diagnosis Procedure for Insufficient Heating.
ATC-100, "Insuffi-
cient Heating"
Noise Go to Trouble Diagnosis Procedure for Noise.
ATC-101, "Noise"
Self-diagnosis cannot be performed. Go to Trouble Diagnosis Procedure for Self-diagnosis. ATC-102, "Self-
diagnosis"
Memory function does not operate. Go to Trouble Diagnosis Procedure for Memory Function. ATC-103, "Memory
Function"

TROUBLE DIAGNOSIS ATC-55
C
D E
F
G H
I
K L
M A
B
AT C
Revision: 2005 July 2005 FX
6. STEP-4: OPERATION OF EACH DOOR MOTOR IS CHECKED
1. Press temperature (UP) switch (driver side).
2. Press (DEF) switch. Code No. of each door motor test is indicated on the display.
>> GO TO 7.
7. CHECK ACTUATORS
Refer to the following chart and confirm discharge air flow, air tem-
perature, blower motor duty ratio and compressor operation.
Checks must be made visually, by listening to any noise, or by touching air outlets with hand, etc. for improper
operation.
*1: FOOT position during automatic control. Refer to AT C - 6 0 , "
AUXILIARY MECHANISM: FOOT POSITION
SETTING TRIMMER" .
OK or NG
OK >> GO TO 8.
NG >>

Air outlet does not change.
Go to Mode Door Motor Circuit. Refer to AT C - 7 0 , "
Mode Door Motor Circuit" .

Intake door does not change.
Go to Intake Door Motor Circuit. Refer to AT C - 7 6 , "
Intake Door Motor Circuit" .

Blower motor operation is malfunctioning.
Go to Blower Motor Circuit. Refer to AT C - 7 9 , "
Blower Motor Circuit" .

Magnet clutch does not engage.
Go to Magnet Clutch Circuit. Refer to AT C - 8 4 , "
Magnet Clutch Circuit" .

Discharge air temperature does not change.
Go to Air Mix Door Motor Circuit. Refer to AT C - 7 3 , "
Air Mix Door Motor Circuit" .
RJIA1968E
SJIA0302E
Code No. 414243444546
Mode door position VENT B/L 1 B/L 2 FOOT
*1D/F DEF
Intake door position REC REC 20% FRE FRE FRE FRE
Air mix door position FULL COLD FULL COLD FULL HOT FULL HOT FULL HOT FULL HOT
Blower motor duty ratio 37% 91% 65% 65% 65% 91%
Compressor ON ON OFF OFF ON ON
Electronic control valve
(ECV) duty ratio 100% 100% 0% 0% 50% 100%

TROUBLE DIAGNOSIS ATC-57
C
D E
F
G H
I
K L
M A
B
AT C
Revision: 2005 July 2005 FX
12. CHECK CAN COMMUNICATION ERROR
1. Press (REC) switch.
2. CAN communication error between unified meter and A/C amp. and display unit or display control unit is detected.
OK or NG
OK >> 1. Turn ignition switch OFF or AUTO switch ON. 2. INSPECTION END
NG >> Go to CAN communication. Refer to BCS-15, "
CAN
Communication Inspection Using CONSULT-II (Self-
Diagnosis)" .

Unified meter and A/C amp. - Display unit

Unified meter and A/C amp. - Display control unit
13. CHECK MALFUNCTIONING SENSOR
Refer to the following chart for malfunctioning code No.
(If two or more sensors malfunction, corresponding code Nos. blink respectively twice.)
*1: Perform self-diagnosis STEP-2 under sunshine.
When performing indoors, aim a light (more than 60 W) at sunload sensor, otherwise code No. 25 will indicate
despite that sunload sensor is functioning properly.
*2: ATC-104, "
DIAGNOSIS PROCEDURE FOR AMBIENT SENSOR" .
*3: ATC-108, "
DIAGNOSIS PROCEDURE FOR IN-VEHICLE SENSOR" .
*4: AT C - 11 3 , "
DIAGNOSIS PROCEDURE FOR INTAKE SENSOR" .
*5: AT C - 11 0 , "
DIAGNOSIS PROCEDURE FOR SUNLOAD SENSOR" .
*6: AT C - 7 5 , "
DIAGNOSIS PROCEDURE FOR AIR MIX DOOR MOTOR PBR" .
>> INSPECTION END
RJIA1969E
Code No. Malfunctioning sensor (Including circuits) Reference page 21 / −21 Ambient sensor *2
22 / −22 In-vehicle sensor *3
24 / −24 Intake sensor *4
25 / −25
Sunload sensor *
1*5
26 / −26 Air mix door motor PBR (Driver side)
*6
27 / −27 Air mix door motor PBR (Passenger side)
RJIA0227E

TROUBLE DIAGNOSIS ATC-61
C
D E
F
G H
I
K L
M A
B
AT C
Revision: 2005 July 2005 FX
Operational CheckAJS0014Q
The purpose of the operational check is to check if the individual system operates properly.
CHECKING MEMORY FUNCTION
1. Set the temperature to 32°C (90 °F).
2. Press OFF switch.
3. Turn ignition switch OFF.
4. Turn ignition switch ON.
5. Press the AUTO switch.
6. Confirm that the set temperature remains at previous tempera- ture.
7. Press OFF switch.
If NG, go to trouble diagnosis procedure for ATC-103, "
Memory
Function" .
If OK, continue the check.
CHECKING BLOWER
1. Press fan (UP) switch. Blower should operate on low speed. The
fan symbol should have one blade lit.
2. Press fan (UP) switch again, and continue checking blower speed and fan symbol until all speeds are checked.
3. Leave blower on max. speed.
If NG, go to trouble diagnosis procedure for AT C - 7 9 , "
Blower Motor
Circuit" .
If OK, continue the check.
CHECKING DISCHARGE AIR
1. Press MODE switch and DEF switch.
2. Each position indicator should change shape.
3. Confirm that discharge air comes out according to the air distri- bution table. Refer to AT C - 3 7 , "
Discharge Air Flow" .
If NG, go to trouble diagnosis procedure for AT C - 7 0 , "
Mode Door
Motor Circuit" .
If OK, continue the check.
NOTE:
Confirm that the compressor clutch is engaged (sound or visual
inspection) and intake door position is at FRESH when the D/F or
DEF is selected. Conditions : Engine running at normal operating temperature
RJIA1972E
RJIA1973E
RJIA1974E
SJIA0302E

ATC-62
TROUBLE DIAGNOSIS
Revision: 2005 July 2005 FX
CHECKING INTAKE AIR
1. Press recirculation (REC) switch one time. Recirculation indica-
tor should illuminate.
2. Press fresh (FRE) switch one time. Fresh indicator should illumi- nate.
3. Listen for intake door position change. (Slight change of blower sound can be heard.)
If NG, go to trouble diagnosis procedure for AT C - 7 6 , "
Intake Door
Motor Circuit" .
If OK, continue the check.
NOTE:
Confirm that the compressor clutch is engaged (sound or visual
inspection) and intake door position is at FRESH when the D/F or DEF is selected.
CHECKING TEMPERATURE DECREASE
1. Press temperature (DOWN) switch (driver side) until 18 °C
(60 °F) is displayed.
2. Check for cold air at discharge air outlets.
If NG, go to trouble diagnosis procedure for AT C - 9 1 , "
Insufficient
Cooling" .
If OK, continue the check.
CHECKING TEMPERATURE INCREASE
1. Press temperature (UP) switch (driver side) until 32 °C (90 °F) is
displayed.
2. Check for hot air at discharge air outlets.
If NG, go to trouble diagnosis procedure for ATC-100, "
Insufficient
Heating" .
If OK, continue the check.
CHECK A/C SWITCH
1. Press AUTO switch and A/C switch.
2. A/C switch indicator will turn ON.

Confirm that the compressor clutch engages (sound or visual
inspection).
If NG, go to trouble diagnosis procedure for AT C - 8 4 , "
Magnet Clutch
Circuit" .
If OK, continue the check.
RJIA1978E
RJIA1976E
RJIA1977E
RJIA1975E

TROUBLE DIAGNOSIS ATC-63
C
D E
F
G H
I
K L
M A
B
AT C
Revision: 2005 July 2005 FX
CHECKING AUTO MODE
1. Press AUTO switch and A/C switch.
2. Display should indicate AUTO.

Confirm that the compressor clutch engages (sound or visual
inspection). (Discharge air and blower speed will depend on
ambient, in-vehicle, and set temperatures.)
If NG, go to trouble diagnosis procedure for AT C - 6 3 , "
Power Supply
and Ground Circuit for Auto Amp." , then if necessary, trouble diag-
nosis procedure for AT C - 8 4 , "
Magnet Clutch Circuit" .
If all operational checks are OK (symptom cannot be duplicated), go
to Incident Simulation Tests in GI-27, "
How to Perform Efficient Diag-
nosis for an Electrical Incident" and perform tests as outlined to sim-
ulate driving conditions environment. If symptom appears, refer to
AT C - 4 2 , "
SYMPTOM TABLE" and perform applicable trouble diagnosis procedures.
Power Supply and Ground Circuit for Auto Amp.AJS001BF
SYMPTOM: A/C system does not come on.
INSPECTION FLOW
RJIA1979E
*1 AT C - 6 4 , "DIAGNOSIS PROCE-
DURE FOR A/C SYSTEM"
*2ATC-61, "Operational Check"*3 AV- 7 8 , "Trouble Diagnosis Chart by
Symptom"
*4AV-166, "A/C Screen Is Not Shown
(NAVI Screen Is Shown)"
RJIA1980E

ATC-64
TROUBLE DIAGNOSIS
Revision: 2005 July 2005 FX
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 switch are operated,
data is input to the unified meter and A/C amp. from the display unit/
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)
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 switch. The set temperature is dis-
played.
DIAGNOSIS PROCEDURE FOR A/C SYSTEM
SYMPTOM: A/C system does not come on.
RJIA1965E
RJIA1982E
RJIA1983E

TROUBLE DIAGNOSIS ATC-65
C
D E
F
G H
I
K L
M A
B
AT C
Revision: 2005 July 2005 FX
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 (R/W), 22 (G/R) and 35 (LG/R), uni-
fied meter and A/C amp. harness connector M57 terminal 46 (L/
W) and ground.
OK or NG
OK >> GO TO 2.
NG >> Check 10 A and 15 A fuses [Nos. 6, 10, 11, 12 and 19, located in the fuse block (J/B)]. Refer to
PG-82, "
FUSE BLOCK - JUNCTION BOX (J/B)" .

If fuses are OK, check harness for open circuit. Repair or replace if necessary.

If fuses are NG, replace fuse and check harness for short circuit. Repair or replace if necessary.
2. CHECK GROUND CIRCUIT FOR UNIFIED METER AND A/C AMP.
1. Turn ignition switch OFF.
2. Check continuity between unified meter and A/C amp. harness connector M56 terminal 29 (B), 30 (B) and ground.
OK or NG
OK >> Replace unified meter and A/C amp.
NG >> Repair harness or connector.
Terminals Ignition switch position
(+)
(-) OFF ACC ON
Unified
meter and A/C amp.
connector Terminal No.
(wire color)
M56 21 (R/W)
Ground Battery volt-
age Battery volt-
age Battery
voltage
M56 22 (G/R) Approx. 0 V Approx. 0 V Battery
voltage
M56 35 (LG/R) Approx. 0 V Battery volt-
age Battery
voltage
M57 46 (L/W) Approx. 0 V Battery volt-
age Battery
voltage
RJIA1984E
29, 30 – Ground : Continuity should exist.
RJIA1985E