air condition INFINITI FX35 2007 Service Manual

AIR CONDITIONER CONTROL ATC-37
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Revision: 2006 July 2007 FX35/FX45
Discharge Air FlowNJS000DR
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ATC-38
AIR CONDITIONER CONTROL
Revision: 2006 July 2007 FX35/FX45
System DescriptionNJS000DS
SWITCHES AND THEIR CONTROL FUNCTION
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AIR CONDITIONER CONTROL ATC-39
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Revision: 2006 July 2007 FX35/FX45
CAN Communication System DescriptionNJS000DT
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-49,
"CAN System Specification Chart" .

ATC-40
TROUBLE DIAGNOSIS
Revision: 2006 July 2007 FX35/FX45
TROUBLE DIAGNOSISPFP:00004
CONSULT-II Function (BCM)NJS000DU
CONSULT-II can display each diagnosis item using the diagnosis test modes shown following.
CONSULT-II BASIC OPERATION
Refer to GI-38, "CONSULT-II Start Procedure" .
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 monitored item can be recorded. To stop recording, touch “STOP”.
Display Item List
How to Perform Trouble Diagnosis for Quick and Accurate RepairNJS000DV
WORK FLOW
System part Check item, diagnosis mode Description
BCM Data monitor Displays BCM input data in real time.
All signals Monitors all the items.
Selection from menu Selects and monitors the individual item selected.
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.
*1 ATC-60, "Operational Check"
SHA900E

ATC-60
TROUBLE DIAGNOSIS
Revision: 2006 July 2007 FX35/FX45
Operational CheckNJS000E1
The purpose of the operational check is to check if the individual system operates properly.
CHECKING MEMORY FUNCTION
1. Press the temperature control (UP) switch (driver side) until 32°C (90 °F) is displayed.
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 temperature.
7. Press OFF switch.
If NG, go to trouble diagnosis procedure for ATC-102, "
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 7 , "
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 - 6 8 , "
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 FRE when the D/F or DEF
is selected.
CHECKING INTAKE AIR
1. Press intake switch. Recirculation indicator should illuminate.
2. Press intake switch again. Fresh indicator should illuminate.
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 4 , "
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 FRE
when the D/F or DEF is selected.
CHECKING TEMPERATURE DECREASE
1. Press temperature control (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 0 , "
Insufficient Cooling" .
If OK, continue the check.
CHECKING TEMPERATURE INCREASE
1. Press temperature control (UP) switch (driver side) until 32 °C (90 °F) is displayed.
Conditions : Engine running at normal operating temperature
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TROUBLE DIAGNOSIS ATC-61
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Revision: 2006 July 2007 FX35/FX45
2. Check for hot air at discharge air outlets.
If NG, go to trouble diagnosis procedure for AT C - 9 9 , "
Insufficient Heating" .
If OK, continue the check.
CHECKING 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 2 , "
Magnet Clutch Circuit" .
If OK, continue the check.
CHECKING AUTO MODE
1. Press AUTO switch and A/C switch.
2. Display should indicate AUTO.

Confirm that 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 2 , "
Power Supply and Ground Circuit for Auto Amp." , then
if necessary, trouble diagnosis procedure for AT C - 8 2 , "
Magnet Clutch Circuit" .
If all operational checks are OK (symptom cannot be duplicated), go to Incident Simulation Tests in GI-28,
"How to Perform Efficient Diagnosis for an Electrical Incident" and perform tests as outlined to simulate driv-
ing conditions environment. If symptom appears, refer to AT C - 4 1 , "
SYMPTOM TABLE" and perform applica-
ble trouble diagnosis procedures.

TROUBLE DIAGNOSIS ATC-87
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Revision: 2006 July 2007 FX35/FX45
8. CHECK REFRIGERANT PRESSURE SENSOR
WITH CONSULT-II
1. Start the engine.
2. Check voltage of refrigerant pressure sensor. Refer to EC-132, "
CONSULT-II Reference Value in Data
Monitor" (VQ35DE) or EC-796, "CONSULT-II Reference Value in Data Monitor" (VK45DE).
WITHOUT CONSULT-II
1. Start the engine.
2. Check voltage between ECM harness connector F101 terminal 70 and ground.
OK or NG
OK >>
WITH CONSULT-II: GO TO 9.

WITHOUT CONSULT-II: GO TO 10.
NG >> Refer to EC-663, "
REFRIGERANT PRESSURE SENSOR" (VQ35DE) or EC-1345, "REFRIGER-
ANT PRESSURE SENSOR" (VK45DE).
9. CHECK BCM INPUT (FAN ON) SIGNAL
Check FAN ON/OFF signal. Refer to AT C - 4 0 , "
CONSULT-II Function
(BCM)" .
OK or NG
OK >> GO TO 12.
NG >> GO TO 10.
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 M3 terminal 28 and unified meter and A/C amp. harness connector M57 ter-
minal 57.
OK or NG
OK >> GO TO 11.
NG >> Repair harness or connector.
Terminals
Condition Voltage
(+)
( − )
ECM
connec-
tor Terminal
No.
F101 70 Ground A/C switch: ON
(Blower motor operates.) Approx. 1.0 - 4.0
V
PBIB1188E
FAN SW ON : FAN ON SIG ON
FAN SW OFF : FAN ON SIG OFF
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28 – 57 : Continuity should exist.
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ATC-88
TROUBLE DIAGNOSIS
Revision: 2006 July 2007 FX35/FX45
11 . CHECK VOLTAGE FOR UNIFIED METER AND A/C AMP. (FAN ON SIGNAL)
1. Reconnect BCM connector and unified meter and A/C amp. connector.
2. Turn ignition switch ON.
3. Check voltage between unified meter and A/C amp. harness connector M57 terminal 57 and ground using an oscilloscope.
OK or NG
OK >> GO TO 12.
NG-1 >> If the voltage is approx. 5 V when blower motor is ON: Replace unified meter and A/C amp.
NG-2 >> If the voltage is approx. 0 V when blower motor is OFF: Replace BCM.
12. CHECK CAN COMMUNICATION
Check CAN communication. Refer to BCS-13, "
CAN Communication Inspection Using CONSULT-II (Self-
Diagnosis)" .

BCM – ECM

ECM – IPDM E/R

ECM – Unified meter and A/C amp.
OK or NG
OK >> Replace ECM
NG >> Repair or replace malfunctioning part(s).
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Terminals
Condition Voltage
(+)
( − )
Unified meter
and A/C amp. connector Terminal No.
M57 57 Ground A/C switch: ON
(Blower motor operates.) Approx. 0 V
OFF switch: ON
(A/C system: OFF)
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ATC-94
TROUBLE DIAGNOSIS
Revision: 2006 July 2007 FX35/FX45
PERFORMANCE CHART
Test Condition
Testing must be performed as follows:
Test Reading
Recirculating-to-discharge Air Temperature Table
Ambient Air Temperature-to-operating Pressure Table
Vehicle condition Indoors or in the shade (in a well-ventilated place)
Doors Closed
Door windows Open
Hood Open
TEMP. Max. COLD
Mode switch (Ventilation) set
Intake switch (Recirculation) set
Fan (blower) speed Max. speed set
Engine speed Idle speed
Operate the air conditioning system for 10 minutes before taking measurements.
Inside air (Recirculating air) at blower assembly inlet Discharge air temperature at center ventilator
° C ( °F)
Relative humidity
% Air temperature
° C ( °F)
50 - 60 20 (68) 11.2 - 13.2 (52 - 56)
25 (77) 12.2 - 14.8 (54 - 59)
30 (86) 15.5 - 18.6 (60 - 65)
35 (95) 21.0 - 24.5 (70 - 76)
40 (104) 28.7 - 32.6 (84 - 91)
60 - 70 20 (68) 13.2 - 15.2 (56 - 59)
25 (77) 14.8 - 17.3 (59 - 63)
30 (86) 18.6 - 21.6 (65 - 71)
35 (95) 24.5 - 28.0 (76 - 82)
40 (104) 32.6 - 36.5 (91 - 98)
Ambient air High-pressure (Discharge side)
kPa (kg/cm
2 , psi) Low-pressure (Suction side)
kPa (kg/cm2 , psi)
Relative humidity
% Air temperature
° C ( °F)
50 - 70 20 (68)
961 - 1,167
(9.8 - 11.9, 139 - 169) 216 - 265
(2.2 - 2.7, 31 - 38)
25 (77) 1,108 - 1,353
(11.3 - 13.8, 161 - 196) 230 - 281
(2.3 - 2.9, 33 - 41)
30 (86) 1,275 - 1,549
(13.0 - 15.8, 185 - 225) 261 - 320
(2.7 - 3.3, 38 - 46)
35 (95) 1,549 - 1,893
(15.8 - 19.3, 225 - 274) 297 - 364
(3.0 - 3.7, 43 - 53)
40 (104) 1,814 - 2,216
(18.5 - 22.6, 263 - 321) 357 - 435
(3.6 - 4.4, 52 - 63)

TROUBLE DIAGNOSIS ATC-97
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Revision: 2006 July 2007 FX35/FX45
Low-pressure Side Sometimes Becomes Negative
Low-pressure Side Becomes Negative
DIAGNOSIS PROCEDURE FOR INSUFFICIENT COOLING
SYMPTOM: Insufficient cooling
1. CHECK POWER SUPPLY FOR ECV (ELECTRONIC CONTROL VALVE)
1. Disconnect compressor (ECV) connector.
2. Turn ignition switch ON.
3. Check voltage between compressor (ECV) harness connector F6 terminal 2 and ground.
OK or NG
OK >> GO TO 2.
NG >> Check power supply circuit and 10A fuse [No. 12, located in the fuse block (J/B)]. Refer to PG-80, "
FUSE
BLOCK - JUNCTION BOX (J/B)" .

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

If fuse is NG, check harness for short circuit and replace fuse.
Gauge indication Refrigerant cycle Probable cause Corrective action
Low-pressure side sometimes
becomes negative.

Air conditioning system
does not function and does
not cyclically cool the com-
partment air.

The system constantly func-
tions for a certain period of
time after compressor is
stopped and restarted. Refrigerant does not dis-
charge cyclically.
↓
Moisture is frozen at expan-
sion valve outlet and inlet.
↓
Water is mixed with refriger-
ant.

Drain water from refrigerant
or replace refrigerant.

Replace liquid tank.
AC354A
Gauge indication Refrigerant cycle Probable cause Corrective action
Low-pressure side becomes nega-
tive.
Liquid tank or front/rear side of
expansion valve’s pipe is
frosted or wet with dew. High-pressure side is closed
and refrigerant does not flow.
↓
Expansion valve or liquid tank
is frosted. Leave the system at rest until
no frost is present. Start it
again to check whether or not
the malfunction is caused by
water or foreign particles.

If water is the cause, initially
cooling is okay. Then the
water freezes causing a
blockage. Drain water from
refrigerant or replace refrig-
erant.

If due to foreign particles,
remove expansion valve
and remove the particles
with dry and compressed air
(not shop air).

If either of the above meth-
ods cannot correct the mal-
function, replace expansion
valve.

Replace liquid tank.

Check lubricant for contami-
nation.
AC362A
2 – ground : Battery voltage
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