Can communication INFINITI QX56 2004 Factory Repair Manual

ATC-1
AUTOMATIC AIR CONDITIONER
J AIR CONDITIONER
CONTENTS
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SECTION AT C
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AT C
Revision: August 20072004 QX56 PRECAUTIONS .......................................................... 5
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” .................................................................. 5
Precautions for Working with HFC-134a (R-134a) ..... 5
Contaminated Refrigerant ........................................ 5
General Refrigerant Precautions .............................. 6
Precautions for Leak Detection Dye ......................... 6
A/C Identification Label ............................................ 7
Precautions for Refrigerant Connection ................... 7
FEATURES OF NEW TYPE REFRIGERANT
CONNECTION ...................................................... 7
O-RING AND REFRIGERANT CONNECTION ..... 8
Precautions for Servicing Compressor ....................11
Precautions for Service Equipment .........................11
RECOVERY/RECYCLING EQUIPMENT .............11
ELECTRONIC LEAK DETECTOR .......................11
VACUUM PUMP ................................................. 12
MANIFOLD GAUGE SET .................................... 12
SERVICE HOSES ............................................... 12
SERVICE COUPLERS ........................................ 13
REFRIGERANT WEIGHT SCALE ...................... 13
CHARGING CYLINDER ...................................... 13
Wiring Diagrams and Trouble Diagnosis ................ 13
PREPARATION ......................................................... 14
Special Service Tools ............................................. 14
HFC-134a (R-134a) Service Tools and Equipment ... 14
Commercial Service Tools ...................................... 17
REFRIGERATION SYSTEM ..................................... 18
Refrigerant Cycle ................................................... 18
REFRIGERANT FLOW ....................................... 18
Refrigerant System Protection ............................... 18
REFRIGERANT PRESSURE SENSOR ............. 18
PRESSURE RELIEF VALVE .............................. 19
Component Layout ................................................. 20
FRONT REFRIGERATION SYSTEM .................. 20
REAR REFRIGERATION SYSTEM .................... 21LUBRICANT .............................................................. 22
Maintenance of Lubricant Quantity in Compressor ... 22
LUBRICANT ........................................................ 22
CHECKING AND ADJUSTING ............................ 22
AIR CONDITIONER CONTROL ............................... 24
Description .............................................................. 24
Operation ................................................................ 24
AIR MIX DOORS CONTROL .............................. 24
FAN SPEED CONTROL ...................................... 24
INTAKE DOOR CONTROL ................................. 24
MODE DOOR CONTROL ................................... 24
DEFROSTER DOOR CONTROL ........................ 24
MAGNET CLUTCH CONTROL ........................... 25
SELF-DIAGNOSTIC SYSTEM ............................ 25
Description of Control System ................................ 26
Control Operation ................................................... 26
DISPLAY SCREEN .............................................. 27
AUTO SWITCH ................................................... 27
TEMPERATURE DIAL (DRIVER) ........................ 27
TEMPERATURE DIAL (PASSENGER) ............... 27
RECIRCULATION SWITCH () ............................. 27
DEFROSTER () SWITCH .................................... 27
REAR WINDOW DEFOGGER SWITCH ............. 27
OFF SWITCH (HOLD FAN DOWN SWITCH
UNTIL SYSTEM SHUTS OFF) ............................ 27
A/C SWITCH ....................................................... 27
MODE SWITCH .................................................. 27
FRONT FAN SWITCH ......................................... 27
REAR FAN SWITCH (FRONT) ............................ 27
REAR TEMPERATURE/MODE DIAL (FRONT) ... 27
REAR TEMPERATURE/MODE DIAL (REAR) .... 28
REAR FAN CONTROL SWITCH (REAR) ........... 28
Discharge Air Flow ................................................. 29
FRONT ................................................................ 29
REAR .................................................................. 29
System Description (Front) ..................................... 30
CONTROLS AND THEIR FUNCTIONS .............. 30
System Description (Rear) ..................................... 31
CONTROLS AND THEIR FUNCTIONS .............. 31
CAN Communication System Description .............. 32

AIR CONDITIONER CONTROL
ATC-25
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Revision: August 20072004 QX56
MAGNET CLUTCH CONTROL
When the A/C or DEF switch is activated, the front air control outputs a compressor ON signal to the BCM.
Upon receiving this input, the BCM sends a compressor ON signal to the ECM via CAN communication lines.
The ECM then judges whether the compressor can be turned ON, based on each sensor status (refrigerant
pressure sensor signal, throttle angle sensor, etc.). If it determines the compressor can be turned ON, a com-
pressor ON signal is sent to the IPDM E/R via CAN communication lines.
Upon receipt of a compressor ON signal, the IPDM E/R turns ON the A/C relay which engages the magnet
clutch and operates the A/C compressor.
SELF-DIAGNOSTIC SYSTEM
A self-diagnostic system is built into the front air control to quickly locate the cause of symptoms. Refer to
ATC-53, "
A/C System Self-diagnosis Function"
WJIA0751E

ATC-32
AIR CONDITIONER CONTROL
Revision: August 20072004 QX56
CAN Communication System DescriptionEJS002C3
Refer to LAN-5, "CAN COMMUNICATION" .

TROUBLE DIAGNOSIS
ATC-33
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TROUBLE DIAGNOSISPFP:00004
CONSULT-II Function (BCM)EJS002C4
CONSULT-II can display each diagnostic item using the diagnostic test modes shown following.
CONSULT-II BASIC OPERATION
CAUTION:
If CONSULT-II is used with no connection of CONSULT-II CONVERTER, malfunctions might be
detected in self-diagnosis depending on control unit which carries out CAN communication.
1. With the ignition switch OFF, connect CONSULT-II and CON-
SULT-II CONVERTER to the data link connector, then turn the
ignition switch ON.
2. Touch “START (NISSAN BASED VHCL)”.
3. Touch “BCM” on “SELECT SYSTEM” screen. If “BCM” is not
indicated, go to GI-39, "
CONSULT-II Data Link Connector (DLC)
Circuit" .
BCM diagnostic
test itemDiagnostic mode Description
Inspection by partWORK SUPPORTSupports inspections and adjustments. Commands are transmitted to the BCM
for setting the status suitable for required operation, input/output signals are
received from the BCM and received data is displayed.
DATA MONITOR Displays BCM input/output data in real time.
ACTIVE TEST Operation of electrical loads can be checked by sending drive signal to them.
SELF-DIAG RESULTS Displays BCM self-diagnosis results.
CAN DIAG SUPPORT MNTR The result of transmit/receive diagnosis of CAN communication can be read.
ECU PART NUMBER BCM part number can be read.
CONFIGURATION Performs BCM configuration read/write functions.
BBIA0369E
BCIA0029E
BCIA0030E

TROUBLE DIAGNOSIS
ATC-55
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SELF-DIAGNOSIS CODE CHART
Code No. Reference page
02 EE changed by calibrationATC-135, "
FRONT AIR CONTROL"
03 Battery voltage out of rangeSC-4, "BATTERY"
04 Mode switch circuit open or shortATC-135, "FRONT AIR CONTROL"
05 Blower motor malfunctionAT C - 8 3 , "Front Blower Motor Circuit"
12 Air mix door motor (Passenger) circuit malfunctionAT C - 7 1 , "DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR
MOTOR (PASSENGER)"
20 BCM not responding to A/C requestATC-104, "Magnet Clutch Circuit"
21 BCM not responding to rear defroster requestGW-78, "REAR WINDOW DEFOGGER"
22 Air mix door motor (Driver) circuit malfunctionAT C - 6 9 , "DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR
MOTOR (DRIVER)"
30 In-vehicle sensor circuit out of range (low)
ATC-128, "In-vehicle Sensor Circuit"31 In-vehicle sensor circuit out of range (high)
34 Air mix door motor (Driver) PBR circuit malfunctionAT C - 6 9 , "
DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR
MOTOR (DRIVER)"
36Air mix door motor (Passenger) PBR circuit malfunc-
tionAT C - 7 1 , "DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR
MOTOR (PASSENGER)"
38 Air mix door motor (rear) circuit malfunctionAT C - 7 3 , "DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR
MOTOR (REAR)"
40 Ambient sensor circuit short
ATC-125, "Ambient Sensor Circuit"41 Ambient sensor circuit open
44 In-vehicle sensor motor circuit open
ATC-128, "
In-vehicle Sensor Circuit"46 In-vehicle sensor motor circuit short
50 Optical sensor (Driver) circuit open or short
ATC-131, "
Optical Sensor Circuit"52 Optical sensor (Passenger) circuit open or short
56 Intake sensor circuit short
ATC-133, "
Intake Sensor Circuit"57 Intake sensor circuit open
62 Defroster door motor circuit malfunctionAT C - 7 9 , "
Defroster Door Motor Circuit"
72 Intake door motor circuit malfunctionAT C - 7 6 , "Intake Door Motor Circuit"
80 CAN bus malfunction
LAN-5, "CAN COMMUNICATION"81 CAN BCM message missing
82 Intake door motor circuit malfunctionAT C - 7 6 , "
Intake Door Motor Circuit"
90 Stuck buttonATC-135, "FRONT AIR CONTROL"
92 Mode door motor circuit malfunctionAT C - 6 3 , "Mode Door Motor Circuit"

TROUBLE DIAGNOSIS
ATC-109
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Revision: August 20072004 QX56
11 . CHECK VOLTAGE FOR FRONT AIR CONTROL (FAN ON SIGNAL)
1. Reconnect BCM connector and front air control connector.
2. Turn ignition switch ON.
3. Check voltage between front air control harness connector M49
terminal 10 (L/R) and ground.
OK or NG
OK >> Check CAN communication. Refer to ATC-32, "CAN Communication System Description" .
NG-1 >> If the voltage is approx. 5V when blower motor is ON, replace front air control. Refer to ATC-135,
"FRONT AIR CONTROL" .
NG-2 >> If the voltage is approx. 0V when blower motor is OFF, replace BCM. Refer to BCS-19, "
Removal
and Installation of BCM" .
Te r m i n a l s
ConditionVo ltag e
(Approx.) (+)
(-)
Front air con-
trol connectorTe r m i n a l N o .
(Wire color)
M49 10 (L/R) GroundA/C switch: ON
Blower motor
operates0V
A/C switch: OFF 5V
WJIA0451E

AV-2Revision: August 20072004 QX56 “VIEW” MODE ..................................................... 70
“HEADING” MODE .............................................. 71
“NEARBY DISPLAY ICONS” MODE ................... 71
“SAVE CURRENT LOCATION” MODE ............... 71
“ADJUST CURRENT LOCATION” MODE ........... 71
“AUTO RE-ROUTE” MODE ................................. 72
“AVOID AREA SETTINGS” MODE ...................... 72
“CLEAR MEMORY” MODE ................................. 72
“EDIT ADDRESS BOOK” MODE ........................ 73
“GPS INFORMATION” MODE ............................. 73
“QUICK STOP CUSTOMER SETTING” MODE ... 73
“SET AVERAGE SPEED” MODE ........................ 73
“TRACKING” MODE ............................................ 74
GUIDANCE VOLUME ......................................... 74
DISPLAY WITH PUSHED “TRIP” BUTTON ........ 74
TRIP 1 OR TRIP 2 ............................................... 75
FUEL ECONOMY ................................................ 75
MAINTENANCE .................................................. 75
ENGINE OIL OR TIRE ROTATION ..................... 75
TIRE PRESSURE ................................................ 76
WARNING INDICATIONS ................................... 76
CAN Communication System Description .............. 76
Component Parts Location ..................................... 77
Schematic ............................................................... 78
Wiring Diagram —NAVI— ....................................... 79
Schematic ............................................................... 86
Wiring Diagram — COMM — ................................. 87
Terminals and Reference Value for NAVI Control
unit .......................................................................... 90
Terminals and Reference Value for Display Control
unit .......................................................................... 92
Terminals and Reference Value for Display unit ..... 96
Terminals and Reference Value for AV Switch ....... 98
Terminals and Reference Value for BCM ................ 99
On Board Self-Diagnosis Function .......................101
DESCRIPTION ..................................................101
DIAGNOSIS ITEM .............................................101
Self-Diagnosis Mode (DCU) .................................101
OPERATION PROCEDURE ..............................101
SELF–DIAGNOSIS RESULT .............................103
Self-Diagnosis Mode (NAVI) .................................104
OPERATION PROCEDURE ..............................104
SELF–DIAGNOSIS RESULT .............................105
Confirmation/Adjustment Mode ............................107
OPERATION PROCEDURE ..............................107
DISPLAY DIAGNOSIS .......................................108
VEHICLE SIGNALS ...........................................108
NAVIGATION .....................................................109
DISPLAY DIAGNOSIS .......................................109
VEHICLE SIGNALS ...........................................110
HISTORY OF ERRORS ....................................110
DIAGNOSIS BY HISTORY OF ERRORS ..........110
NAVIGATION .....................................................112
CAN DIAG SUPPORT MONITOR ........................114
OPERATION PROCEDURE ..............................114
AV Switch Self-Diagnosis Function .......................115
Power Supply and Ground Circuit Check for NAVI
Control Unit ...........................................................116
Power Supply and Ground Circuit Check for Display Control Unit ...........................................................117
Power Supply and Ground Circuit Check for Display
Unit ........................................................................118
Power Supply and Ground Circuit Check for AV
Switch ................................................................... 120
Vehicle Speed Signal Check for NAVI Control Unit . 121
Vehicle Speed Signal Check for Display Control Unit . 122
Illumination Signal Check for NAVI Control Unit ... 123
Illumination Signal Check for Display Control Unit . 123
Ignition Signal Check for NAVI Control Unit .......... 123
Ignition Signal Check for Display Control Unit ...... 124
Reverse Signal Check for NAVI Control Unit ........ 124
Reverse Signal Check for Display Control Unit .... 124
AV Communication Line Check (Between Display
Control Unit and NAVI Control Unit) ...................... 125
Audio Communication Line Check (Between Dis-
play Control Unit and Audio Unit) .......................... 126
Display Communication Line Check (Between Dis-
play Control Unit and Display Unit) ....................... 128
AV Communication Line Check (Between Display
Control Unit and AV Switch) .................................. 130
CAN Communication Line Check ......................... 131
If NAVI Control Unit Detects That DVD-ROM Map
is Not Inserted ....................................................... 131
If NAVI Control Unit Detects That Inserted DVD-
ROM Map Malfunctioning or If It is Impossible to
Load Data from DVD-ROM Map ........................... 131
If Connection Between NAVI Control Unit and GPS
Antenna is Malfunctioning ..................................... 132
Operating Screen for Audio and A/C is Not Dis-
played When Showing NAVI Screen ..................... 132
Color of RGB Image is Not Proper (Only NAVI
Screen Looks Bluish) ............................................ 134
Color of RGB Image is Not Proper (Only NAVI
Screen Looks Reddish) ......................................... 135
Color of RGB Image is Not Proper (Only NAVI
Screen Looks Yellowish) ....................................... 136
Color of RGB Image is Not Proper (All Screen Looks
Bluish) ................................................................... 137
Color of RGB Image is Not Proper (All Screen Looks
Reddish) ................................................................ 138
Color of RGB Image is Not Proper (All Screen Looks
Yellowish) .............................................................. 139
NAVI Screen is Rolling .......................................... 140
Guide Sound is Not Heard .................................... 142
Screen is Not Shown ............................................ 143
A/C Screen is Not Shown (NAVI Screen is Shown) . 143
FUEL ECONOMY Screen is Not Shown ............... 143
Average Fuel Economy Displayed is Not Shown (“
*** ” is Shown) ....................................................... 143
Distance to Empty Displayed is Not Shown (“ *** ”
is Shown) .............................................................. 144
Driving Distance or Average Speed Displayed is Not
Shown (“ *** ” is Shown) ....................................... 144
WARNING DOOR OPEN Screen is Not Shown ... 144
Unable to Operate All of AV Switches (Unable to
Start Self-Diagnosis) ............................................. 145
Audio Does Not Work ........................................... 145
Navigation System Does Not Activate .................. 145

AV-76
NAVIGATION SYSTEM
Revision: August 20072004 QX56
TIRE PRESSURE

Pressure indication in psi on the screen indicates that the
pressure is being measured. After a few trips, the pressures for
all four tires will be displayed.

The order of tire pressure figures displayed on the screen does
not correspond with the actual order of tire position.

Tire pressure rises and falls depending on the heat caused by
the vehicle's traveling condition and the temperature.

In case of low tire pressure, the low tire pressure warning light
will come on and/or a warning is displayed on the screen.

FLAT TIRE – very low tire pressure.
NOTE:

In a case of FLAT TIRE pressure, interrupt screen is not shown on the display.

On the screen of TIRE PRESSURE, "FLAT TIRE Check All tires" is displayed.
WARNING INDICATIONS
Warning signal (Door switch signal) is received from BCM through
CAN communication line.
CAN Communication System DescriptionEKS008IM
Refer to LAN-5, "CAN COMMUNICATION" .
WKIA1809E
WKIA1957E
Warning indicatorsWarning lamps in
instrument panelWarning detection and cancel conditions Cases of malfunction
DOOR OPEN DoorDetection conditionVehicle is running [approx. 5 km/h
(3 MPH) or faster] and door ajar of
any of the doors is detected.
Door is open
Cancel conditionVehicle is stopped and all the
doors lock.

NAVIGATION SYSTEM
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Revision: August 20072004 QX56
On Board Self-Diagnosis FunctionEKS007LT
DESCRIPTION

Diagnosis function consists of the self-diagnosis mode performed automatically and the CONFIRMATION/
ADJUSTMENT mode operated manually.

Self-diagnosis mode checks for connections between the units constituting this system, analyzes each
individual unit at the same time, and displays the results on the LCD screen.

CONFIRMATION/ADJUSTMENT mode is used to perform trouble diagnosis that require operation and
judgment by an operator (trouble that cannot be automatically judged by the system), to check/change the
set value, and to display the History of Errors of the navigation system.
DIAGNOSIS ITEM
NOTE:
Make the status that is set by D/N function be shown.
Self-Diagnosis Mode (DCU)EKS007LU
OPERATION PROCEDURE
1. Start the engine.
2. Turn the audio system off.
Mode Description
Self-diagnosis (DCU) Display control unit diagnosis.
Self-diagnosis (NAVI)

NAVI Control unit diagnosis (DVD-ROM drive) will not be diagnosed
when no map DVD-ROM is in it.

Analyzes connection between the NAVI control unit and the GPS
antenna and operation of each unit.
CONFIRMATION/
ADJUSTMENTDisplay diagnosisIn display control unit mode, color tone and shading of the screen can be
checked by the display of a color bar and a gray scale.
Vehicle signalsIn display control unit mode, analyzes the following vehicle signals: Vehi-
cle speed signal, light signal
NOTE , ignition switch signal, and reverse sig-
nal.
Auto Climate Control A/C self-diagnosis of A/C system.
NavigationDisplay diagnosisIn NAVI C/U mode, color tone and shading of the screen can be checked
by the display of a color bar and a gray scale.
Vehicle signalsIn NAVI C/U mode, analyzes the following vehicle signals: Vehicle speed
signal, light signal, ignition switch signal, and reverse signal.
History of ErrorsDiagnosis results previously stored in the memory (before turning ignition
switch ON) are displayed in this mode. Time and location when/where the
errors occurred are also displayed.
Naviga-
tionDisplay Lon-
gitude & Lat-
itudeDisplay the map. Use the joystick to adjust position. Longitude and latitude
will be displayed.
Speed Cali-
brationUnder ordinary conditions, the navigation system distance measuring
function will automatically compensate for minute decreases in wheel and
tire diameter caused by tire wear or low-pressure. Speed calibration imme-
diately restores system accuracy in cases such as when distance calibra-
tion is needed because of the use of tire chains in inclement weather.
Angle
adjustmentCorrects difference between actual turning angle of a vehicle and turning
angle of the car mark on the display.
Initialize
LocationThis mode is for initializing the current location. Use when the vehicle is
transported a long distance on a trailer, etc.
CAN DIAG SUPPORT MONITOR Display status of CAN communication.

NAVIGATION SYSTEM
AV-103
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Revision: August 20072004 QX56
7. On the “SELF DIAGNOSIS” screen, each unit name will be col-
ored according to the diagnosis result, as follows.

If several malfunctions are present in a unit, color of its switch
on the screen will be either red, yellow, or gray, determined by
the malfunction of the highest priority.
8. Select a switch on the “SELF DIAGNOSIS” screen and com-
ments for the diagnosis results will be shown.

When the switch is green, the following comment will be
shown. “Self-diagnosis was successful. Further diagnosis and
adjustments are recommended. Follow the “confirmation/
adjustment” menu or refer to the service manual.”

When the switch is yellow, the following comment will be
shown. “Connection to the following unit is abnormal. See the
service manual for further details”.

When the switch is red, the following comment will be shown.
“DCU is abnormal”.
SELF–DIAGNOSIS RESULT
Quick reference table
1. Select a malfunctioning diagnosis No. in the diagnosis result quick reference table.
2. Find estimated malfunctioning system in the diagnosis No. table and perform check by referring to AV-87,
"Wiring Diagram — COMM —" .
3. Turn the ignition switch OFF and perform self-diagnosis again.
*: DCU = Display control unit
CAUTION:

When AV switch has a malfunction, you cannot start. Refer to AV-145, "Unable to Operate All of AV
Switches (Unable to Start Self-Diagnosis)" .

When display unit has a malfunction, you cannot start. Refer to AV-143, "Screen is Not Shown" .
Self-Diagnosis Codes
Green : Not malfunctioning.
Yellow : Cannot be judged by self-diagnosis results.
Red : Unit is malfunctioning.
Gray : Diagnosis has not been done.
WKIA1189E
SKIA4 211 E
Screen switch
Diagnosis No.
Switch color DCU* DISPLAY Audio unit NavigationGPS
antenna
Red×1
Gray×x2
xx 3
×××4
Diagnosis
No.Possible causeReference
page
1 Display control unit malfunction Refer to AV-158
.
2 Display communication line between display control unit and display unit Refer to AV-128
.
3Audio unit power supply and ground circuit
Audio communication line between display control unit and audio unitRefer to AV-126
.
4NAVI control unit power supply and ground circuit
AV communication line between display control unit and NAVI control unitRefer to AV-125
.