Can communication INFINITI QX56 2004 Factory Service Manual

LAN-126
[CAN]
CAN SYSTEM (TYPE 4)
Revision: August 20072004 QX56
CAN SYSTEM (TYPE 4)PFP:23710
System DescriptionUKS001NP
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.
Component Parts and Harness Connector LocationUKS001NQ
BKIA0121E

CAN SYSTEM (TYPE 4)
LAN-131
[CAN]
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Work FlowUKS001NT
1. When there are no indications of “AUTO DRIVE POS.”, “BCM” or “IPDM E/R” on “SELECT SYSTEM” dis-
play of CONSULT-II, print the “SELECT SYSTEM”.
2. Print all the data of “SELF-DIAG RESULTS” for “ENGINE”, “A/T”, “ICC”, “AUTO DRIVE POS.”, “BCM”,
“ALL MODE AWD/4WD”, “ABS” and “IPDM E/R” displayed on CONSULT-II.
3. Print all the data of “CAN DIAG SUPPORT MNTR” for “ENGINE”, “A/T”, “ICC”, “AUTO DRIVE POS.”,
“BCM”, “ALL MODE AWD/4WD”, “ABS” and “IPDM E/R” displayed on CONSULT-II.
4. Attach the printed sheet of “SELECT SYSTEM”, “SELF-DIAG RESULTS” and “CAN DIAG SUPPORT
MNTR” onto the check sheet. Refer to LAN-133, "
CHECK SHEET" .
5. Based on the indications of “SELECT SYSTEM” and the results of “CAN DIAG SUPPORT MNTR”, put
marks “v” onto the items with “No indication”, “NG” or “UNKWN” in the check sheet table. Refer to LAN-
133, "CHECK SHEET" .
NOTE:

If “NG” is displayed on “INITIAL DIAG (Initial diagnosis)” as “CAN DIAG SUPPORT MNTR” for the diag-
nosed control unit, replace the control unit.

The “CAN DIAG SUPPORT MNTR” items, which are not in check sheet table, are not related to diag-
nostic procedure on service manual.
So it is not necessary to check the status of the “CAN DIAG SUPPORT MNTR” items not in check
sheet table.
6. Check CAN communication line of the navigation system. Refer to AV-131, "
CAN Communication Line
Check" .
7. Attach the CAN DIAG SUPPORT MONITOR check sheet onto the check sheet. Refer to LAN-133,
"CHECK SHEET" .
PKIA2093E
PKIA8260E
PKIA8343E

LAN-132
[CAN]
CAN SYSTEM (TYPE 4)
Revision: August 20072004 QX56
8. Mark the “NG” or “UNKWN” item of the check sheet table with “v” from the result of CAN DIAG SUPPORT
MONITOR check sheet. Refer to LAN-133, "
CHECK SHEET" .
NOTE:
If “NG” is displayed on “CAN COMM” as “CAN DIAG SUPPORT MONITOR” for the diagnosed control
unit, replace the control unit. Refer to AV- 1 3 1 , "
CAN Communication Line Check" .
9. According to the check sheet results (example), start inspection. Refer to LAN-135, "
CHECK SHEET
RESULTS (EXAMPLE)" .

LAN-154
[CAN]
CAN SYSTEM (TYPE 4)
Revision: August 20072004 QX56
Case 20
Check CAN communication circuit. Refer to LAN-166, "CAN Communication Circuit Check" .
Case 21
Check IPDM E/R ignition relay circuit continuously sticks “OFF”. Refer to LAN-166, "IPDM E/R Ignition Relay
Circuit Check" .
PKIA8131E
PKIA8132E

LAN-166
[CAN]
CAN SYSTEM (TYPE 4)
Revision: August 20072004 QX56
CAN Communication Circuit CheckUKS001O9
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Disconnect the following module and control unit connectors and check terminals for deformation, discon-
nection, looseness or damage.
–ECM
–A/T assembly
–ICC sensor
–ICC unit
–Driver seat control unit
–Combination meter
–Display control unit
–BCM
–Steering angle sensor
–Front air control
–Transfer control unit
–ABS actuator and electric unit (control unit)
–IPDM E/R
OK or NG
OK >> GO TO 2.
NG >> Repair or replace as necessary.
2. CHECK HARNESS FOR SHORT CIRCUIT
With all module and control unit connectors disconnected, check
continuity between data link connector M22 terminals 6 (W) and 14
(R).
OK or NG
OK >> GO TO 3.
NG >> Repair harness.
3. CHECK HARNESS FOR SHORT CIRCUIT
Check continuity between data link connector M22 terminals 6 (W),
14 (R) and ground.
OK or NG
OK >> Check ECM and IPDM E/R. Refer to LAN-167, "ECM/
IPDM E/R INTERNAL CIRCUIT INSPECTION" .
NG >> Repair harness.
IPDM E/R Ignition Relay Circuit CheckUKS001OA
Check the following. If no malfunction is found, replace the IPDM E/R.

IPDM E/R power supply circuit. Refer to PG-27, "IPDM E/R Power/Ground Circuit Inspection" . 6 (W) - 14 (R) : Continuity should not exist.
PKIA2077E
6 (W) - Ground : Continuity should not exist.
14 (R) - Ground : Continuity should not exist.
PKIA2079E

LT-1
LIGHTING SYSTEM
K ELECTRICAL
CONTENTS
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SECTION LT
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Revision: August 20072004 QX56 PRECAUTIONS .......................................................... 4
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” .................................................................. 4
General precautions for service operations ............. 5
Wiring Diagrams and Trouble Diagnosis .................. 5
HEADLAMP (FOR USA) ............................................ 6
Component Parts and Harness Connector Location ..... 6
System Description .................................................. 6
OUTLINE ............................................................... 6
XENON HEADLAMP ............................................. 7
BATTERY SAVER CONTROL .............................. 8
AUTO LIGHT OPERATION ................................... 8
VEHICLE SECURITY SYSTEM (PANIC ALARM) ..... 8
CAN Communication System Description ................ 8
Schematic ................................................................ 9
Wiring Diagram — H/LAMP — ............................... 10
Terminals and Reference Values for BCM ............. 14
Terminals and Reference Values for IPDM E/R ..... 15
How to Proceed With Trouble Diagnosis ................ 15
Preliminary Check .................................................. 16
CHECK POWER SUPPLY AND GROUND CIR-
CUIT .................................................................... 16
CONSULT-II Function (BCM) ................................. 18
CONSULT-II OPERATION .................................. 18
WORK SUPPORT ............................................... 19
DATA MONITOR ................................................. 19
ACTIVE TEST ..................................................... 20
SELF-DIAGNOSTIC RESULTS .......................... 20
CONSULT-II Function (IPDM E/R) ......................... 21
CONSULT-II OPERATION .................................. 21
DATA MONITOR ................................................. 22
ACTIVE TEST ..................................................... 22
Headlamp HI Does Not Illuminate (Both Sides) ..... 23
Headlamp HI Does Not Illuminate (One Side) ....... 25
High Beam Indicator Lamp Does Not Illuminate .... 26
Headlamp LO Does Not Illuminate (Both Sides) .... 26
Headlamp LO Does Not Illuminate (One Side) ...... 28
Headlamps Do Not Turn OFF ................................ 29
Aiming Adjustment ................................................. 31LOW BEAM AND HIGH BEAM ........................... 31
Bulb Replacement .................................................. 32
HEADLAMP (OUTER SIDE), FOR LOW BEAM ... 32
HEADLAMP (INNER SIDE), FOR HIGH BEAM ... 32
FRONT PARKING LAMP (INNER OR OUTER) ... 32
FRONT SIDE MARKER LAMP ........................... 32
Removal and Installation ........................................ 33
REMOVAL ........................................................... 33
INSTALLATION ................................................... 33
Disassembly and Assembly .................................... 33
HEADLAMP (FOR CANADA) - DAYTIME LIGHT
SYSTEM - .................................................................. 34
Component Parts and Harness Connector Location ... 34
System Description ................................................. 35
OUTLINE ............................................................. 35
DAYTIME LIGHT OPERATION ........................... 35
COMBINATION SWITCH READING FUNCTION ... 35
AUTO LIGHT OPERATION ................................. 35
CAN Communication System Description .............. 35
Schematic ............................................................... 36
Wiring Diagram — DTRL — ................................... 37
Terminals and Reference Values for BCM .............. 41
How to Proceed With Trouble Diagnosis ................ 42
Preliminary Check .................................................. 42
CHECK BCM CONFIGURATION ........................ 42
INSPECTION FOR POWER SUPPLY AND
GROUND CIRCUIT ............................................. 42
INSPECTION PARKING BRAKE SWITCH CIR-
CUIT .................................................................... 43
CONSULT-II Functions ........................................... 44
Daytime Light Control Does Not Operate Properly
(Normal Headlamps Operate Properly) .................. 44
Aiming Adjustment .................................................. 46
Bulb Replacement .................................................. 46
Removal and Installation ........................................ 46
Disassembly and Assembly .................................... 46
AUTO LIGHT SYSTEM ............................................. 47
Component Parts and Harness Connector Location ... 47
System Description ................................................. 48
OUTLINE ............................................................. 48

LT-2Revision: August 20072004 QX56 COMBINATION SWITCH READING FUNCTION ... 48
EXTERIOR LAMP BATTERY SAVER CONTROL ... 48
DELAY TIMER FUNCTION ................................. 48
CAN Communication System Description .............. 48
Major Components and Functions .......................... 48
Schematic ............................................................... 49
Wiring Diagram — AUTO/L — ................................ 50
Terminals and Reference Values for BCM .............. 53
Terminals and Reference Values for IPDM E/R ...... 54
How to Proceed With Trouble Diagnosis ................ 55
Preliminary Check .................................................. 55
SETTING CHANGE FUNCTIONS ....................... 55
CHECK POWER SUPPLY AND GROUND CIR-
CUIT .................................................................... 55
CONSULT-II Function (BCM) .................................. 57
CONSULT-II OPERATION ................................... 57
WORK SUPPORT ............................................... 58
DATA MONITOR .................................................. 58
ACTIVE TEST ..................................................... 59
SELF-DIAGNOSTIC RESULTS ........................... 59
CONSULT-II Function (IPDM E/R) .......................... 60
CONSULT-II OPERATION ................................... 60
DATA MONITOR .................................................. 61
ACTIVE TEST ..................................................... 61
Trouble Diagnosis Chart by Symptom .................... 62
Lighting Switch Inspection ...................................... 62
Optical Sensor System Inspection .......................... 63
Removal and Installation of Optical Sensor ............ 64
REMOVAL ........................................................... 64
INSTALLATION .................................................... 64
HEADLAMP AIMING CONTROL .............................. 65
System Description ................................................. 65
Wiring Diagram — H/AIM — ................................... 66
Removal and Installation ........................................ 68
Switch Circuit Inspection ........................................ 68
FRONT FOG LAMP .................................................. 69
Component Parts and Harness Connector Location ... 69
System Description ................................................. 69
OUTLINE ............................................................. 69
COMBINATION SWITCH READING FUNCTION ... 70
EXTERIOR LAMP BATTERY SAVER CONTROL ... 70
CAN Communication System Description .............. 70
Wiring Diagram — F/FOG — .................................. 71
Terminals and Reference Values for BCM .............. 73
Terminals and Reference Values for IPDM E/R ...... 74
How to Proceed With Trouble Diagnosis ................ 74
Preliminary Check .................................................. 75
CHECK POWER SUPPLY AND GROUND CIR-
CUIT .................................................................... 75
CONSULT-II Functions ........................................... 76
Front Fog Lamps Do Not Illuminate (Both Sides) ... 76
Front Fog Lamp Does Not Illuminate (One Side) ... 77
Aiming Adjustment .................................................. 78
Bulb Replacement .................................................. 79
Removal and Installation ........................................ 79
TURN SIGNAL AND HAZARD WARNING LAMPS ... 80
Component Parts and Harness Connector Location ... 80
System Description ................................................. 80
OUTLINE ............................................................. 80TURN SIGNAL OPERATION ...............................80
HAZARD LAMP OPERATION .............................81
REMOTE KEYLESS ENTRY SYSTEM OPERA-
TION ....................................................................82
COMBINATION SWITCH READING FUNCTION ...82
CAN Communication System Description ..............82
Wiring Diagram — TURN — ...................................83
Terminals and Reference Values for BCM ..............85
How to Proceed With Trouble Diagnosis ................86
Preliminary Check ...................................................87
CHECK POWER SUPPLY AND GROUND CIR-
CUIT .....................................................................87
CONSULT-II Function (BCM) ..................................88
CONSULT-II OPERATION ...................................88
DATA MONITOR ..................................................89
ACTIVE TEST ......................................................89
Turn Signal Lamp Does Not Operate ......................90
Rear Turn Signal Lamp Does Not Operate .............91
Hazard Warning Lamp Does Not Operate But Turn
Signal Lamps Operate ............................................92
Turn Signal Indicator Lamp Does Not Operate .......93
Bulb Replacement (Front Turn Signal Lamp) ..........94
Bulb Replacement (Rear Turn Signal Lamp) ..........94
Removal and Installation of Front Turn Signal Lamp ...94
Removal and Installation of Rear Turn Signal Lamp ...94
LIGHTING AND TURN SIGNAL SWITCH ................95
Removal and Installation .........................................95
REMOVAL ............................................................95
INSTALLATION ....................................................95
HAZARD SWITCH .....................................................96
Removal and Installation .........................................96
REMOVAL ............................................................96
INSTALLATION ....................................................96
COMBINATION SWITCH ..........................................97
Wiring Diagram — COMBSW — ............................97
Combination Switch Reading Function ...................98
CONSULT-II Function (BCM) ..................................98
CONSULT-II OPERATION ...................................98
DATA MONITOR ..................................................99
Combination Switch Inspection ............................. 100
Removal and Installation ....................................... 102
Switch Circuit Inspection ....................................... 102
STOP LAMP ............................................................ 103
System Description ............................................... 103
Wiring Diagram — STOP/L — .............................. 104
High-Mounted Stop Lamp ..................................... 105
BULB REPLACEMENT ...................................... 105
REMOVAL AND INSTALLATION ....................... 105
Stop Lamp ............................................................. 105
BULB REPLACEMENT ...................................... 105
REMOVAL AND INSTALLATION ....................... 105
BACK-UP LAMP ..................................................... 106
Wiring Diagram — BACK/L — .............................. 106
Bulb Replacement ................................................. 107
Removal and Installation ....................................... 107
PARKING, LICENSE PLATE AND TAIL LAMPS .... 108
Component Parts and Harness Connector Location . 108
System Description ............................................... 108
OPERATION BY LIGHTING SWITCH ............... 109

LT-3
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Revision: August 20072004 QX56 COMBINATION SWITCH READING FUNCTION . 109
EXTERIOR LAMP BATTERY SAVER CONTROL . 109
CAN Communication System Description ............ 109
Schematic ............................................................. 110
Wiring Diagram — TAIL/L — ................................ . 111
Terminals and Reference Values for BCM ............ 114
Terminals and Reference Values for IPDM E/R .... 115
How to Proceed With Trouble Diagnosis ............... 115
Preliminary Check ................................................. 116
CHECK POWER SUPPLY AND GROUND CIR-
CUIT ................................................................... 116
CONSULT-II Functions .......................................... 117
Parking, License Plate and/or Tail Lamps Do Not
Illuminate ............................................................... 117
Parking, License Plate and Tail Lamps Do Not Turn
OFF (After Approx. 10 Minutes) ........................... 120
Front Parking Lamp .............................................. 121
BULB REPLACEMENT ..................................... 121
Tail Lamp .............................................................. 121
BULB REPLACEMENT ..................................... 121
License Plate Lamp .............................................. 121
BULB REPLACEMENT ..................................... 121
REAR COMBINATION LAMP ................................ 122
Bulb Replacement (Turn Signal) .......................... 122
Removal and Installation ...................................... 122
.......................................................................... 122
TRAILER TOW ....................................................... 123
Component Parts and Harness Connector Location . 123
System Description .............................................. 123
TRAILER TAIL LAMP OPERATION .................. 124
TRAILER BRAKE, TURN SIGNAL AND HAZARD
LAMP OPERATION .......................................... 124
TRAILER BRAKE OPERATION ........................ 124
TRAILER POWER SUPPLY OPERATION ........ 124
Schematic ............................................................ 125
Wiring Diagram — T/TOW — ............................... 126
INTERIOR ROOM LAMP ........................................ 129
Component Parts and Harness Connector Location . 129
System Description .............................................. 130POWER SUPPLY AND GROUND ....................130
SWITCH OPERATION ......................................131
ROOM LAMP TIMER OPERATION ..................131
INTERIOR LAMP BATTERY SAVER CONTROL .132
Schematic .............................................................133
Wiring Diagram — INT/L — ..................................135
Terminals and Reference Values for BCM ............142
How to Proceed With Trouble Diagnosis ..............142
Preliminary Check ................................................143
INSPECTION FOR POWER SUPPLY AND
GROUND CIRCUIT ...........................................143
CONSULT-II Function (BCM) ...............................144
CONSULT-II OPERATION .................................144
WORK SUPPORT .............................................145
DATA MONITOR ...............................................145
ACTIVE TEST ...................................................146
Room/Map Lamp Control Does Not Operate .......146
Personal Lamp Control Does Not Operate (Room/
Map Lamps Operate) ............................................148
All Step/Foot/Puddle Lamps Do Not Operate .......149
All Interior Room Lamps Do Not Operate .............150
Ignition Keyhole Illumination Control Does Not
Operate .................................................................150
ILLUMINATION .......................................................152
Component Parts and Harness Connector Location .152
System Description ...............................................152
ILLUMINATION OPERATION BY LIGHTING
SWITCH ............................................................153
EXTERIOR LAMP BATTERY SAVER CONTROL .154
CAN Communication System Description ............154
Schematic .............................................................155
Wiring Diagram — ILL — ......................................158
Removal and Installation ......................................169
ILLUMINATION CONTROL SWITCH ................169
BULB SPECIFICATIONS ........................................170
Headlamp .............................................................170
Exterior Lamp .......................................................170
Interior Lamp/Illumination .....................................170

LT-6
HEADLAMP (FOR USA)
Revision: August 20072004 QX56
HEADLAMP (FOR USA)PFP:26010
Component Parts and Harness Connector LocationEKS0079P
System DescriptionEKS0079Q
Control of the headlamp system operation is dependent upon the position of the combination switch (lighting
switch). When the lighting switch is placed in the 2ND position, the BCM (body control module) receives input
requesting the headlamps (and tail lamps) illuminate. This input is communicated to the IPDM E/R (intelligent
power distribution module engine room) across the CAN communication lines. The CPU (central processing
unit) of the IPDM E/R controls the headlamp high and headlamp low relay coils. When energized, these relays
direct power to the respective headlamps, which then illuminate.
OUTLINE
Power is supplied at all times

to headlamp high relay, located in the IPDM E/R, and

to headlamp low relay, located in the IPDM E/R, and

to ignition relay, located in the IPDM E/R, and

through 20A fuse (No. 53, located in the IPDM E/R)

to CPU of the IPDM E/R, and

through 10A fuse [No. 19, located in the fuse block (J/B)]
WKIA3392E

HEADLAMP (FOR USA)
LT-7
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Revision: August 20072004 QX56

to combination meter terminal 8, and

through 50A fusible link (letter f , located in the fuse and fusible link box)

to BCM terminal 70.
With the ignition switch in the ON or START position, power is supplied

to ignition relay, located in the IPDM E/R, and

through 10A fuse [No. 14, located in the fuse block (J/B)]

to combination meter terminal 24, and

through 10A fuse (No. 59, located in the fuse and relay box)

to BCM terminal 38.
Ground is supplied

to BCM terminal 67 and

to combination meter terminal 17

through grounds M57, M61 and M79, and

to IPDM E/R terminals 38 and 59

through grounds E9, E15 and E24.
Low Beam Operation
With the lighting switch in 2ND position, the BCM receives input requesting the headlamps to illuminate. This
input is communicated to the IPDM E/R across the CAN communication lines. The CPU of the IPDM E/R con-
trols the headlamp low relay coil. When energized, this relay directs power

through 15A fuse (No. 41, located in the IPDM E/R)

through IPDM E/R terminal 54

to front combination lamp RH terminal 5, and

through 15A fuse (No. 40, located in the IPDM E/R)

through IPDM E/R terminal 52

to front combination lamp LH terminal 5.
Ground is supplied

to front combination lamp LH and RH terminal 1

through grounds E9, E15 and E24.
With power and ground supplied, low beam headlamps illuminate.
High Beam Operation/Flash-to-Pass Operation
With the lighting switch in 2ND position and placed in HIGH or PASS position, the BCM receives input request-
ing the headlamp high beams to illuminate. This input is communicated to the IPDM E/R across the CAN com-
munication lines. The CPU of the combination meter controls the ON/OFF status of the HIGH BEAM indicator.
The CPU of the IPDM E/R controls the headlamp high relay coil. When energized, this relay directs power

through 10A fuse (No. 34, located in the IPDM E/R)

through IPDM E/R terminal 56

to front combination lamp RH terminal 6, and

through 10A fuse (No. 35, located in the IPDM E/R)

through IPDM E/R terminal 55

to front combination lamp LH terminal 6.
Ground is supplied

to front combination lamp LH and RH terminal 2

through grounds E9, E15 and E24.
With power and ground supplied, the high beam headlamps illuminate.
XENON HEADLAMP
Xenon type headlamp is adopted to the low beam headlamps. Xenon bulbs do not use a filament. Instead,
they produce light when a high voltage current is passed between two tungsten electrodes through a mixture
of xenon (an inert gas) and certain other metal halides. In addition to added lighting power, electronic control
of the power supply gives the headlamps stable quality and tone color.
Following are some of the many advantages of the xenon type headlamp.