INFINITI QX4 2005 Factory Service Manual

LAN-162
[CAN]
CAN SYSTEM (TYPE 4)
Revision: October 20052005 QX56
Driver Seat Control Unit Circuit CheckUKS001NZ
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Check following terminals and connectors for damage, bend and loose connection (control unit side and
harness side).
–Driver seat control unit connector
–Harness connector P1
–Harness connector B37
OK or NG
OK >> GO TO 2.
NG >> Repair terminal or connector.
2. CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect driver seat control unit connector.
2. Check resistance between driver seat control unit harness con-
nector P2 terminals 3 (L) and 19 (P).
OK or NG
OK >> Replace driver seat control unit.
NG >> Repair harness between driver seat control unit and har-
ness connector B69.
Combination Meter Circuit CheckUKS001O0
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Check terminals and connector of combination meter for damage, bend and loose connection (meter side
and harness side).
OK or NG
OK >> GO TO 2.
NG >> Repair terminal or connector.
2. CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect combination meter connector.
2. Check resistance between combination meter harness connec-
tor M24 terminals 11 (L) and 12 (P).
OK or NG
OK >> Replace combination meter.
NG >> Repair harness between combination meter and data
link connector. 3 (L) - 19 (P) : Approx. 54 - 66 Ω
PKIA6842E
11 (L) - 12 (P) : Approx. 54 - 66 Ω
PKIA6837E

CAN SYSTEM (TYPE 4)
LAN-163
[CAN]
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Revision: October 20052005 QX56
Display Control Unit Circuit CheckUKS001O1
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Check terminals and connector of display control unit for damage, bend and loose connection (control unit
side and harness side).
OK or NG
OK >> GO TO 2.
NG >> Repair terminal or connector.
2. CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect display control unit connector.
2. Check resistance between display control unit harness connec-
tor M95 terminals 25 (L) and 26 (P).
OK or NG
OK >> Replace display control unit.
NG >> Repair harness between display control unit and data
link connector.
BCM Circuit CheckUKS001O2
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Check terminals and connector of BCM for damage, bend and loose connection (control module side and
harness side).
OK or NG
OK >> GO TO 2.
NG >> Repair terminal or connector.
2. CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect BCM connector.
2. Check resistance between BCM harness connector M18 termi-
nals 39 (L) and 40 (P).
OK or NG
OK >> Replace BCM. Refer to BCS-20, "Removal and Installa-
tion of BCM" .
NG >> Repair harness between BCM and data link connector.25 (L) - 26 (P) : Approx. 54 - 66 Ω
SKIA6884E
39 (L) - 40 (P) : Approx. 54 - 66 Ω
SKIA6869E

LAN-164
[CAN]
CAN SYSTEM (TYPE 4)
Revision: October 20052005 QX56
Data Link Connector Circuit CheckUKS001O3
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Check terminals and connector of data link connector for damage, bend and loose connection (connector
side and harness side).
OK or NG
OK >> GO TO 2.
NG >> Repair terminal or connector.
2. CHECK HARNESS FOR OPEN CIRCUIT
Check resistance between data link connector M22 terminals 6 (L)
and 14 (P).
OK or NG
OK >> Diagnose again. Refer to LAN-131, "Work Flow" .
NG >> Repair harness between data link connector and combi-
nation meter.
Steering Angle Sensor Circuit CheckUKS001O4
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Check terminals and connector of steering angle sensor for damage, bend and loose connection (sensor
side and harness side).
OK or NG
OK >> GO TO 2.
NG >> Repair terminal or connector.
2. CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect steering angle sensor connector.
2. Check resistance between steering angle sensor harness con-
nector M47 terminals 3 (L) and 4 (P).
OK or NG
OK >> Replace steering angle sensor.
NG >> Repair harness between steering angle sensor and data
link connector. 6 (L) - 14 (P) : Approx. 54 - 66 Ω
PKIA2077E
3 (L) - 4 (P) : Approx. 54 - 66 Ω
PKIA6838E

CAN SYSTEM (TYPE 4)
LAN-165
[CAN]
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Revision: October 20052005 QX56
Front Air Control Circuit CheckUKS001O5
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Check terminals and connector of front air control for damage, bend and loose connection (unit side and
harness side).
OK or NG
OK >> GO TO 2.
NG >> Repair terminal or connector.
2. CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect front air control connector.
2. Check resistance between front air control harness connector
M50 terminals 34 (L) and 35 (P).
OK or NG
OK >> Replace front air control.
NG >> Repair harness between front air control and data link
connector.
Transfer Control Unit Circuit CheckUKS001O6
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Check terminals and connector of transfer control unit for damage, bend and loose connection (control
unit side and harness side).
OK or NG
OK >> GO TO 2.
NG >> Repair terminal or connector.
2. CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect transfer control unit connector.
2. Check resistance between transfer control unit harness connec-
tor E142 terminals 7 (L) and 8 (P).
OK or NG
OK >> Replace transfer control unit.
NG >> Repair harness between transfer control unit and har-
ness connector E152. 34 (L) - 35 (P) : Approx. 54 - 66 Ω
PKIA8136E
7 (L) - 8 (P) : Approx. 54 - 66 Ω
PKIA6844E

LAN-166
[CAN]
CAN SYSTEM (TYPE 4)
Revision: October 20052005 QX56
ABS Actuator and Electric Unit (Control Unit) Circuit CheckUKS001O7
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Check terminals and connector of ABS actuator and electric unit (control unit) for damage, bend and loose
connection (control unit side and harness side).
OK or NG
OK >> GO TO 2.
NG >> Repair terminal or connector.
2. CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect ABS actuator and electric unit (control unit) connector.
2. Check resistance between ABS actuator and electric unit (con-
trol unit) harness connector E125 terminals 11 (L) and 15 (P).
OK or NG
OK >> Replace ABS actuator and electric unit (control unit).
NG >> Repair harness between ABS actuator and electric unit
(control unit) and harness connector E152.
IPDM E/R Circuit CheckUKS001O8
1. CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the negative battery terminal.
3. Check terminals and connector of IPDM E/R for damage, bend and loose connection (control module side
and harness side).
OK or NG
OK >> GO TO 2.
NG >> Repair terminal or connector.
2. CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect IPDM E/R connector.
2. Check resistance between IPDM E/R harness connector E122
terminals 39 (L) and 40 (P).
OK or NG
OK >> Replace IPDM E/R.
NG >> Repair harness between IPDM E/R and harness con-
nector E152. 11 (L) - 15 (P) : Approx. 54 - 66 Ω
SKIA6872E
39 (L) - 40 (P) : Approx. 108 - 132 Ω
PKIA8141E

CAN SYSTEM (TYPE 4)
LAN-167
[CAN]
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Revision: October 20052005 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 (L) and 14
(P).
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 (L),
14 (P) and ground.
OK or NG
OK >> Check ECM and IPDM E/R. Refer to LAN-168, "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-26, "IPDM E/R Power/Ground Circuit Inspection" . 6 (L) - 14 (P) : Continuity should not exist.
PKIA2077E
6 (L) - Ground : Continuity should not exist.
14 (P) - Ground : Continuity should not exist.
PKIA2079E

LAN-168
[CAN]
CAN SYSTEM (TYPE 4)
Revision: October 20052005 QX56

Ignition power supply circuit. Refer to PG-13, "IGNITION POWER SUPPLY — IGNITION SW. IN ON
AND/OR START" .
Component InspectionUKS001OB
ECM/IPDM E/R INTERNAL CIRCUIT INSPECTION

Remove ECM and IPDM E/R from vehicle.

Check resistance between ECM terminals 94 and 86.

Check resistance between IPDM E/R terminals 39 and 40.
Unit TerminalResistance value (Ω)
(Approx.)
ECM 94 - 86
108 - 132
IPDM E/R 39 - 40
LKIA0037E

LT-1
LIGHTING SYSTEM
K ELECTRICAL
CONTENTS
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SECTION LT
A
B
LT
Revision: October 20052005 QX56 PRECAUTIONS .......................................................... 4
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” .................................................................. 4
General precautions for service operations ............. 4
Wiring Diagrams and Trouble Diagnosis .................. 4
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 .................................................. 15
CHECK POWER SUPPLY AND GROUND CIR-
CUIT .................................................................... 15
CONSULT-II Function (BCM) ................................. 17
CONSULT-II OPERATION .................................. 17
WORK SUPPORT ............................................... 18
DATA MONITOR ................................................. 18
ACTIVE TEST ..................................................... 19
SELF-DIAGNOSTIC RESULTS .......................... 19
CONSULT-II Function (IPDM E/R) ......................... 20
CONSULT-II OPERATION .................................. 20
DATA MONITOR ................................................. 21
ACTIVE TEST ..................................................... 21
Headlamp HI Does Not Illuminate (Both Sides) ..... 22
Headlamp HI Does Not Illuminate (One Side) ....... 24
High Beam Indicator Lamp Does Not Illuminate .... 25
Headlamp LO Does Not Illuminate (Both Sides) .... 25
Headlamp LO Does Not Illuminate (One Side) ...... 27
Headlamps Do Not Turn OFF ................................ 28
Aiming Adjustment ................................................. 30LOW BEAM AND HIGH BEAM ........................... 30
Bulb Replacement .................................................. 31
HEADLAMP (OUTER SIDE), FOR LOW BEAM ... 31
HEADLAMP (INNER SIDE), FOR HIGH BEAM ... 31
FRONT PARKING LAMP (INNER OR OUTER) ... 31
FRONT SIDE MARKER LAMP ........................... 31
Removal and Installation ........................................ 32
REMOVAL ........................................................... 32
INSTALLATION ................................................... 32
Disassembly and Assembly .................................... 32
HEADLAMP (FOR CANADA) - DAYTIME LIGHT
SYSTEM - .................................................................. 33
Component Parts and Harness Connector Location ... 33
System Description ................................................. 34
OUTLINE ............................................................. 34
DAYTIME LIGHT OPERATION ........................... 34
COMBINATION SWITCH READING FUNCTION ... 34
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: October 20052005 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 of Headlamp Aiming
Switch ..................................................................... 68
REMOVAL ........................................................... 68
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 ... 80Component Parts and Harness Connector Location ...80
System Description .................................................80
OUTLINE .............................................................80
TURN 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

LT-3
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Revision: October 20052005 QX56 Component Parts and Harness Connector Location . 108
System Description .............................................. 108
OPERATION BY LIGHTING SWITCH .............. 109
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 ................................................. 115
CHECK POWER SUPPLY AND GROUND CIR-
CUIT ................................................................... 115
CONSULT-II Functions .......................................... 116
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 TURN SIGNAL AND HAZARD LAMP
OPERATION ..................................................... 124
TRAILER STOP LAMP OPERATION ................ 124
TRAILER POWER SUPPLY OPERATION ........ 124
Schematic ............................................................ 125
Wiring Diagram — T/TOW — ............................... 126
INTERIOR ROOM LAMP ........................................ 129
Component Parts and Harness Connector Location . 129System Description ...............................................130
POWER 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 ..............143
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 of Illumination Control
Switch ...................................................................169
REMOVAL .........................................................169
INSTALLATION .................................................169
BULB SPECIFICATIONS ........................................170
Headlamp .............................................................170
Exterior Lamp .......................................................170
Interior Lamp/Illumination .....................................170