2004 INFINITI QX56 Can communication

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
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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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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
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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
.

NAVIGATION SYSTEM
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Revision: August 20072004 QX56
If an error occurred before the ignition switch was turned to ON and does not occur again until the “Self-diag-
nosis” is completed, the diagnosis result will be judged normal. Therefore, those errors in the past which can-
not be found by the “Self-diagnosis” must be found by diagnosing the “History of Errors”.
The History of Errors displays the time and place of the most recent occurrence of that error. However, take
note of the following points.

Correct time of the error occurrence may not be displayed when the GPS antenna substrate within the
NAVI control unit has malfunctioned.

Place of the error occurrence is represented by the position of the current-location mark at the time when
the error occurred. If the current-location mark has deviated from the correct position, then the place of
the error occurrence may be located correctly.

The maximum number of occurrences which can be stored is 50. For the 51st and later occurrences, the
displayed number remains 50.
When a reproducible malfunction occurred but its cause cannot be identified because several errors are
present, record the item, number and place (longitude/latitude) of error occurrence (or delete the History of
Errors), then turn the ignition switch from OFF to ON to reproduce the malfunction. Check the History of Errors
to find the items which show an increased number of occurrences, and diagnose the item.
Error itemPossible causes
Example of symptom
Action/symptom
Gyro sensor
disconnectedCommunications malfunction between NAVI control unit and inter-
nal gyro.

Navigation location detection performance
has deteriorated.
(Angular velocity cannot be detected.)
Perform self-diagnosis.

When the NAVI control unit is judged normal by self-diagnosis,
the symptom may be intermittent, caused by strong radio inter-
ference.
GPS discon-
nectedCommunication error between NAVI control unit and internal GPS
substrate.

Navigation location detection performance
has deteriorated.
(Location correction using GPS is not per-
formed.)

GPS receiving status remains gray.

Perform self-diagnosis.

When the NAVI control unit is judged normal by self-diagnosis,
the symptom may be intermittent, caused by strong radio inter-
ference.
GPS trans-
mission cable
malfunctionMalfunctioning transmission wires to NAVI control unit and internal
GPS substrate.

During self-diagnosis, GPS diagnosis is not
performed.
Perform self-diagnosis.

When the NAVI control unit is judged normal by self-diagnosis,
the symptom may be intermittent, caused by strong radio inter-
ference.
GPS input
line connec-
tion errorMalfunctioning receiving wires to NAVI control unit and internal
GPS substrate.

Navigation location detection performance
has deteriorated.
(Location correction using GPS is not per-
formed.)

GPS receiving status remains gray.

Perform self-diagnosis.

When the NAVI control unit is judged normal by self-diagnosis,
the symptom may be intermittent, caused by strong radio inter-
ference.
GPS TCX0
over
GPS TCX0
underOscillating frequency of the GPS substrate frequency synchroniz-
ing oscillation circuit exceeded (or below) the specification

Navigation location detection performance
has deteriorated.
(Location correction using GPS is not per-
formed.)

GPS receiving status remains gray.

Perform self-diagnosis.

When the NAVI control unit is judged normal by self-diagnosis,
the symptom may be intermittent, caused by strong radio inter-
ference, or the control unit may have been subjected to exces-
sively high or low temperatures.
GPS ROM
malfunction
GPS RAM
malfunctionContents of ROM (or RAM) in GPS substrate are malfunctioning.

Location detection accuracy of the navigation
system will deteriorate, depending on the error
area in the memory, because GPS cannot
make correct positioning.
(Location correction using GPS is not per-
formed.)

Perform self-diagnosis.

When the NAVI control unit is judged normal by self-diagnosis,
the symptom may be intermittent, caused by strong radio inter-
ference.

AV-114
NAVIGATION SYSTEM
Revision: August 20072004 QX56
CAN DIAG SUPPORT MONITOREKS007LX
OPERATION PROCEDURE
1. Start the engine.
2. Turn the audio system off.
3. While pressing the “PAUSE/MUTE” button, turn the volume con-
trol dial clockwise or counterclockwise for 30 clicks or more.
(When the self-diagnosis mode is started, a short beep will be
heard.)

Shifting from current screen to previous screen is performed
by pressing “PREV” button.
4. The initial self-diagnosis screen will be shown, and items “Self-
Diagnosis (DCU)”, “Self-Diagnosis (NAVI)”, “Confirmation/
Adjustment” and “CAN DIAG SUPPORT MONITOR” will
become selective.
5. Select “CAN DIAG SUPPORT MONITOR”.
6. Display status of CAN communication.

If the ignition is turned on and UNKWN is shown on the screen, the value of the counter will be up.
(MAX50)
WKIA1504E
SKIA4207E
Item Content Error counter
CANCOMM OK/NG 0-50
CAN_CIRC_1 OK/UNKWN 0-50
CAN_CIRC_2 OK/UNKWN 0-50
CAN_CIRC_3 OK/UNKWN 0-50
CAN_CIRC_4 OK/UNKWN 0-50
CAN_CIRC_5 OK/UNKWN 0-50
CAN_CIRC_6 OK/UNKWN 0-50
CAN_CIRC_7 OK/UNKWN 0-50
CAN_CIRC_8 OK/UNKWN 0-50
CAN_CIRC_9 OK/UNKWN 0-50
SKIA4288E