2004 INFINITI QX56 ignition

LAN-2Revision: August 20072004 QX56 IPDM E/R Ignition Relay Circuit Check ................... 89
Component Inspection ............................................ 89
ECM/IPDM E/R INTERNAL CIRCUIT INSPEC-
TION .................................................................... 89
CAN SYSTEM (TYPE 3) ........................................... 90
System Description ................................................. 90
Component Parts and Harness Connector Location ... 90
Schematic ............................................................... 91
Wiring Diagram - CAN - .......................................... 92
Work Flow ............................................................... 95
CHECK SHEET ................................................... 97
CHECK SHEET RESULTS (EXAMPLE) ............. 99
Circuit Check Between TCM and Driver Seat Con-
trol Unit .................................................................115
Circuit Check Between Driver Seat Control Unit and
Data Link Connector .............................................116
Circuit Check Between Data Link Connector and
IPDM E/R ..............................................................117
ECM Circuit Check ...............................................118
TCM Circuit Check ...............................................118
Driver Seat Control Unit Circuit Check .................119
Combination Meter Circuit Check .........................119
Display Control Unit Circuit Check ........................120
BCM Circuit Check ...............................................120
Data Link Connector Circuit Check .......................121
Steering Angle Sensor Circuit Check ...................121
Front Air Control Circuit Check .............................122
Transfer Control Unit Circuit Check ......................122
ABS Actuator and Electric Unit (Control Unit) Circuit
Check ...................................................................123
IPDM E/R Circuit Check .......................................123
CAN Communication Circuit Check ......................124
IPDM E/R Ignition Relay Circuit Check .................124
Component Inspection ..........................................125
ECM/IPDM E/R INTERNAL CIRCUIT INSPEC-
TION ..................................................................125CAN SYSTEM (TYPE 4) .......................................... 126
System Description ............................................... 126
Component Parts and Harness Connector Location . 126
Schematic ............................................................. 127
Wiring Diagram - CAN - ........................................ 128
Work Flow ............................................................. 131
CHECK SHEET ................................................. 133
CHECK SHEET RESULTS (EXAMPLE) ............ 135
Circuit Check Between TCM and ICC Sensor ...... 155
Circuit Check Between ICC Sensor and ICC Unit . 156
Circuit Check Between ICC Unit and Driver Seat
Control Unit ........................................................... 157
Circuit Check Between Driver Seat Control Unit and
Data Link Connector ............................................. 157
Circuit Check Between Data Link Connector and
IPDM E/R .............................................................. 158
ECM Circuit Check ................................................ 159
TCM Circuit Check ................................................ 159
ICC Sensor Circuit Check ..................................... 160
ICC Unit Circuit Check .......................................... 160
Driver Seat Control Unit Circuit Check .................. 161
Combination Meter Circuit Check ......................... 161
Display Control Unit Circuit Check ........................ 162
BCM Circuit Check ................................................ 162
Data Link Connector Circuit Check ....................... 163
Steering Angle Sensor Circuit Check .................... 163
Front Air Control Circuit Check ............................. 164
Transfer Control Unit Circuit Check ...................... 164
ABS Actuator and Electric Unit (Control Unit) Circuit
Check .................................................................... 165
IPDM E/R Circuit Check ........................................ 165
CAN Communication Circuit Check ...................... 166
IPDM E/R Ignition Relay Circuit Check ................. 166
Component Inspection .......................................... 167
ECM/IPDM E/R INTERNAL CIRCUIT INSPEC-
TION .................................................................. 167

PRECAUTIONS
LAN-3
[CAN]
C
D
E
F
G
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L
MA
B
LAN
Revision: August 20072004 QX56
PRECAUTIONSPFP:00001
Precautions for Supplemental Restraint System (SRS) “AIR BAG” and “SEAT
BELT PRE-TENSIONER”
UKS0017I
The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and whether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SRS and SB section of this Service Man-
ual.
WA RN ING:

To avoid rendering the SRS inoperative, which could increase the risk of personal injury or death
in the event of a collision which would result in air bag inflation, all maintenance must be per-
formed by an authorized NISSAN/INFINITI dealer.

Improper maintenance, including incorrect removal and installation of the SRS, can lead to per-
sonal injury caused by unintentional activation of the system. For removal of Spiral Cable and Air
Bag Module, see the SRS section.

Do not use electrical test equipment on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identified by yellow and/or orange harnesses or
harness connectors.
Precautions When Using CONSULT-IIUKS0017J
When connecting CONSULT-II to data link connector, connect them through CONSULT-II CONVERTER.
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 carry out CAN communication.
CHECK POINTS FOR USING CONSULT-II
1. Has CONSULT-II been used without connecting CONSULT-II CONVERTER on this vehicle?
–If YES, GO TO 2.
–If NO, GO TO 5.
2. Is there any indication other than indications relating to CAN communication system in the self-diagnosis
results?
–If YES, GO TO 3.
–If NO, GO TO 4.
3. Based on self-diagnosis results unrelated to CAN communication, carry out the inspection.
4. Malfunctions may be detected in self-diagnosis depending on control units carrying out CAN communica-
tion. Therefore, erase the self-diagnosis results.
5. Diagnose CAN communication system. Refer to LAN-5, "
CAN Communication Unit" .
Precautions For Trouble DiagnosisUKS0017K
CAN SYSTEM

Do not apply voltage of 7.0V or higher to the measurement terminals.

Use the tester with its open terminal voltage being 7.0V or less.

Be sure to turn ignition switch off and disconnect negative battery terminal before checking the circuit.

LAN-6
[CAN]
CAN COMMUNICATION
Revision: August 20072004 QX56
Engine coolant temperature signal T R R R
A/T self-diagnosis signal R T
Accelerator pedal position signal T R R
Closed throttle position signal T R
Wide open throttle position signal T R
Battery voltage signal T R
Key switch signal R T
Ignition switch signal R T R
P range signal T R
Stop lamp switch signal R T R
Parking brake switch signal T R
Fuel consumption monitor signalTR
TR
Turbine revolution signal R T
Output shaft revolution signal R T
A/C switch signal R T
A/C compressor request signal T R R
Blower fan motor switch signal R T R
A/C switch/indicator signalTR
RT
Cooling fan speed request signal T R R
Position light request signal R T R
Low beam request signal T R
Low beam status signal RT
High beam request signal R T R
High beam status signal RT
Front fog light request signal T R
Day time running light request signal T R
Vehicle speed signalRRT
RRRTRR R
Sleep wake up signal R T R
Door switch signal R R R T R
Turn indicator signal R T
Key fob ID signal R T
Key fob door unlock signal R T
Buzzer output signal R T
Fuel level sensor signal R T
Fuel level low warning signal T R
ASCD SET lamp signal T R
ASCD CRUISE lamp signal T RSignals ECM TCMDriver
seat
con-
trol
unitCom-
bina-
tion
meterDis-
play
con-
trol
unitBCMStee r-
ing
angle
sensorFront
air
control ABS
actua-
tor and
elec-
tric unit
(con-
trol
unit)IPDM
E/R

LAN-8
[CAN]
CAN COMMUNICATION
Revision: August 20072004 QX56
TYPE2
System diagram

Type2
Input/output signal chart
T: Transmit R: Receive
PKIA8134E
Signals ECM TCMICC
sen-
sorICC
unitDriver
seat
con-
trol
unitCom-
bina-
tion
mete
rDis-
play
con-
trol
unitBCMSteer-
ing
angle
sensorFront
air
con-
trol ABS
actu-
ator
and
elec-
tric
unit
(con-
trol
unit)IPD
M E/
R
Engine speed signal T R R R R R
Engine status signal T R R
Engine coolant temperature signal T R R R
A/T self-diagnosis signal R T
Accelerator pedal position signal T R R R
Closed throttle position signal T R R
Wide open throttle position signal T R
Battery voltage signal T R
Key switch signal R T
Ignition switch signal R T R
P range signal T R R
Stop lamp switch signal R T R
Parking brake switch signal T R
Fuel consumption monitor signalTR
TR
Turbine revolution signal R T R
Output shaft revolution signal R T R
A/C switch signal R T
A/C compressor request signal T R R
Blower fan motor switch signal R T R

CAN COMMUNICATION
LAN-11
[CAN]
C
D
E
F
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B
LAN
Revision: August 20072004 QX56
Input/output signal chart
T: Transmit R: Receive
Signals ECM TCMDriver
seat
con-
trol
unitCom-
bina-
tion
meterDis-
play
con-
trol
unitBCMStee r-
ing
angle
sen-
sorFront
air
con-
trolTran s-
fer
con-
trol
unitABS
actua-
tor
and
elec-
tric
unit
(con-
trol
unit)IPDM
E/R
A/T self-diagnosis signal R T
Stop lamp switch signal R T R
Parking brake switch signal T R
Battery voltage signal T R
Key switch signal R T
Ignition switch signal R T R
P range signal T R
Closed throttle position signal T R
Wide open throttle position signal T R
Engine speed signal T R R R R R
Engine status signal T R R
Engine coolant temperature signal T R R R
Accelerator pedal position signal T R R R
Fuel consumption monitor signalTR
TR
Turbine revolution signal R T
Output shaft revolution signal R T R
A/C switch signal R T
A/C compressor request signal T R R
Blower fan motor switch signal R T R
A/C switch/indicator signalTR
RT
Cooling fan speed request signal T R R
Position light request signal R T R
Low beam request signal T R
Low beam status signal RT
High beam request signal R T R
High beam status signal RT
Front fog light request signal T R
Day time running light request signal T R
Vehicle speed signalRRRT
RRRT RR R
Sleep wake up signal R T R
Door switch signal R R R T R
Turn indicator signal R T
Key fob ID signal R T
Key fob door unlock signal R T

CAN COMMUNICATION
LAN-13
[CAN]
C
D
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B
LAN
Revision: August 20072004 QX56
TYPE 4
System diagram

Ty p e 4
Input/output signal chart
T: Transmit R: Receive
PKIA8135E
Signals ECM TCMICC
sen-
sorICC
unitDriver
seat
con-
trol
unitCom-
bina-
tion
mete
rDis-
play
con-
trol
unitBCMStee r-
ing
angle
sen-
sorFront
air
con-
trolTra ns -
fer
con-
trol
unitABS
actu-
ator
and
elec-
tric
unit
(con-
trol
unit)IPD
M
E/R
A/T self-diagnosis signal R T
Stop lamp switch signal R T R
Parking brake switch signal T R
Battery voltage signal T R
Key switch signal R T
Ignition switch signal R T R
P range signal T R R
Closed throttle position signal T R R
Wide open throttle position signal T R
Engine speed signal T R R R R R R
Engine status signal T R R
Engine coolant temperature sig-
nalTR R R
Accelerator pedal position signal T R R R R
Fuel consumption monitor signalTR
TR
Turbine revolution signal R T R
Output shaft revolution signal R T R R
A/C switch signal R T
A/C compressor request signal T R R
Blower fan motor switch signal R T R

CAN SYSTEM (TYPE 1)
LAN-39
[CAN]
C
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LAN
Revision: August 20072004 QX56
Case 15
Check CAN communication circuit. Refer to LAN-48, "CAN Communication Circuit Check" .
Case 16
Check IPDM E/R ignition relay circuit continuously sticks “OFF”. Refer to LAN-49, "IPDM E/R Ignition Relay
Circuit Check" .
PKIA8064E
PKIA8065E

LAN-40
[CAN]
CAN SYSTEM (TYPE 1)
Revision: August 20072004 QX56
Case 17
Check IPDM E/R ignition relay circuit continuously sticks “ON”. Refer to LAN-49, "IPDM E/R Ignition Relay Cir-
cuit Check" .
Circuit Check Between TCM and Driver Seat Control UnitUKS0018I
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 (connector side and
harness side).
–Harness connector F33
–Harness connector E19
–Harness connector E34
–Harness connector B40
OK or NG
OK >> GO TO 2.
NG >> Repair terminal or connector.
2. CHECK HARNESS FOR OPEN CIRCUIT
1. Disconnect A/T assembly connector and harness connector F33.
2. Check continuity between A/T assembly harness connector F9
terminals 3 (W), 8 (R) and harness connector F33 terminals 12
(W), 11 (R).
OK or NG
OK >> GO TO 3.
NG >> Repair harness.
PKIA8066E
3 (W) - 12 (W) : Continuity should exist.
8 (R) - 11 (R) : Continuity should exist.
PKIA6831E