EC-30Revision: October 2005
AUTOMATIC SPEED CONTROL DEVICE (ASCD)
2005 QX56
COAST OPERATION
When the SET/COAST switch is pressed during cruise control driving, decrease vehicle set speed until the
switch is released. And then ASCD will keep the new set speed.
RESUME OPERATION
When the RESUME/ACCELERATE switch is pressed after cancel operation other than pressing MAIN switch
is performed, vehicle speed will return to last set speed. To resume vehicle set speed, vehicle condition must
meet following conditions.
Brake pedal is released
A/T selector lever is in other than P and N positions
Vehicle speed is greater than 40 km/h (25 MPH) and less than 144 km/h (89 MPH)
Component DescriptionUBS00KZD
ASCD STEERING SWITCH
Refer to EC-552 .
ASCD BRAKE SWITCH
Refer to EC-569 , and EC-657 .
STOP LAMP SWITCH
Refer to EC-569 , EC-586 and EC-657 .
ELECTRIC THROTTLE CONTROL ACTUATOR
Refer to EC-397 , EC-399 , EC-405 and EC-410 .
ASCD INDICATOR
Refer to EC-664 .
EC-664Revision: October 2005
ASCD INDICATOR
2005 QX56
ASCD INDICATORPFP:24814
Component DescriptionUBS00HDT
ASCD indicator lamp illuminates to indicate ASCD operation status. Lamp has two indicators, CRUISE and
SET, and is integrated in combination meter.
CRUISE indicator illuminates when MAIN switch on ASCD steering switch is turned ON to indicate that ASCD
system is ready for operation.
SET indicator illuminates when following conditions are met.
CRUISE indicator is illuminated.
SET/COAST switch on ASCD steering switch is turned ON while vehicle speed is within the range of
ASCD setting.
SET indicator remains lit during ASCD control.
Refer to EC-29, "
AUTOMATIC SPEED CONTROL DEVICE (ASCD)" for the ASCD function.
CONSULT-II Reference Value in Data Monitor ModeUBS00HDU
Specification data are reference value.
MONITOR ITEM CONDITION SPECIFICATION
CRUISE LAMP
Ignition switch: ONMAIN switch: Pressed at the 1st
time → at the 2nd timeON → OFF
SET LAMP
MAIN switch: ON
When vehicle speed is
between 40 km/h (25 MPH)
and 144 km/h (89 MPH)
ASCD: Operating ON
ASCD: Not operating OFF
IDX-5
A
C
D
E
F
G
H
I
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IDX
ALPHABETICAL INDEX
GPS antenna ..................................................... AV-62
Grease .............................................................. MA-11
Ground distribution ............................................ PG-29
H
H/AIM - Wiring diagram ...................................... LT-66
Handling precautions for plastics ..................... BL-187
Harness connector ............................................ PG-67
Harness layout .................................................. PG-39
Hazard warning lamp ......................................... LT-80
Headlamp aiming control ................................... LT-66
Headlamp leveler - See Headlamp aiming control . LT-
66
Headlamp removal and installation .................... LT-32
Heated oxygen sensor 2 (bank 1) .... EC-216, EC-225,
EC-415
, EC-426
Heated oxygen sensor 2 (bank 2) .... EC-216, EC-225,
EC-415
, EC-426
Heated oxygen sensor 2 heater (bank 1) ........ EC-166
Heated oxygen sensor 2 heater (bank 2) ........ EC-166
Heated seat ....................................................... SE-90
Heater and cooling unit (Heater core) . ATC-156, ATC-
160
Heater unit (heater core) ............... ATC-156, ATC-160
Height (Dimensions) ........................................... GI-49
HFC134a (R134a) system identification ........... ATC-7
HFC134a (R134a) system precaution ............... ATC-5
HFC134a (R134a) system service procedure ATC-175
HFC134a (R134a) system service tools ......... ATC-14
HFC134a system service equipment precaution ATC-
11
High & low reverse clutch solenoid valve . AT-152, AT-
154
Homelink universal transceiver ........................ BL-156
Horn ................................................................ WW-58
HORN - Wiring diagram .................................. WW-58
How to erase DTC for OBD system .................. EC-62
HSEAT - Wiring diagram ................................... SE-92
I
I/MIRR - Wiring diagram ................................... GW-75
IATS - Wiring diagram ..................................... EC-192
ICC - Wiring diagram ....................................... ACS-20
ICC/BS - Wiring diagram ................................. EC-562
ICC/SW - Wiring diagram ................................ EC-547
ICCBOF - Wiring diagram ............................... EC-650
Identification plate .............................................. GI-47
Idle air volume learning ..................................... EC-91
Idle mixture ratio ................................................ EC-79
Idle speed .............................................. EC-72, EC-77
Idle speed control (ISC) .................... EC-374, EC-376
Ignition coil .......................................... EM-26, EC-619
Ignition control system .................................... EC-619
Ignition key hole illumination ............................ LT-129
Ignition timing ........................................ EC-72, EC-77
IGNSYS - Wiring diagram ............................... EC-620
ILL - Wiring diagram ......................................... LT-158
Illumination ....................................................... LT-152
In vehicle sensor ........................... ATC-140, ATC-149
INJECT - Wiring diagram ................................. EC-632
Injector ............................................................. EC-631
Input clutch solenoid valve ................. AT-140, AT-142
Instrument panel .................................................. IP-10
Instrument panel speaker .................................. AV-46
Intake air temperature sensor ............ EC-191, EC-211
Intake door control linkage adjustment . ATC-85, ATC-
88
Intake door motor ........................... ATC-83, ATC-164
Intake manifold .................................................. EM-15
Intake sensor ................................ ATC-145, ATC-151
Integrated homelink transmitter - See Homelink univer-
sal tranceiver .................................................... BL-156
Intelligent cruise control (ICC) system ............... ACS-6
Interior ................................................................. EI-35
Interior lamp ...................................................... LT-129
Interior lamp on-off control ................................ LT-130
Internal gear (Transfer) ....................... TF-147, TF-174
IPDM (Intelligent power distribution module engine
room) ................................................................. PG-17
IVIS (Infiniti vehicle immobilizer system) .......... BL-137
IVIS (Infiniti vehicle immobilizer system) precautions ...
GI-3
J
Jacking points ..................................................... GI-40
Junction box (J/B) .............................................. PG-76
K
Key illumination ................................................ LT-130
KEYLES - Wiring diagram .................................. BL-49
Knock sensor (KS) ........................................... EC-279
KS - Wiring diagram ........................................ EC-280
L
Length (Dimensions) .......................................... GI-49
License lamp .................................................... LT-108
Lifting points ....................................................... GI-41
Line pressure solenoid valve ........................... AT-119
Line pressure switch (Transfer) .......... TF-152, TF-165
Line pressure test (A/T) ..................................... AT-51
Location of electrical units ................................. PG-63
Low coast brake solenoid valve .......... AT-156, AT-158
Low tire pressure warning system ...................... WT-8
Low tire pressure warning system - trouble diagnoses
WT-11
Low tire pressure warning system - Wiring diagram .....
WT-11
Lubricant (R134a) A/C ..................................... ATC-22
Lubricants .......................................................... MA-11
Lubrication circuit (engine) .................................. LU-5
Lubrication oil A/C ........................................... ATC-22
Lubrication-locks, hinges and hood latches ....... MA-31
CAN COMMUNICATION
LAN-7
[CAN]
C
D
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MA
B
LAN
Revision: October 20052005 QX56
Fuel level sensor signal R T
Fuel level low warning signal T R
ASCD SET lamp signal T R
ASCD CRUISE lamp signal T R
Malfunction indicator lamp signal T R
Front wiper request signal T R
Front wiper stop position signal R T
Rear window defogger switch signal T R R
Rear window defogger control signal R R R T
Hood switch signalRT
Theft warning horn request signal T R
Horn chirp signalTR
Steering angle sensor signalTR
ABS warning lamp signal R T
VDC OFF indicator lamp signal R T
SLIP indicator lamp signal R T
Brake warning lamp signal R T
System setting signalRT
TR
Distance to empty signal T R
ASCD operation signal T R
ASCD OD cancel request T R
A/T CHECK indicator lamp signal T R
A/T position indicator lamp signal T R
Tire pressure signal R T
Tire pressure data signal R T
1st position switch signal R T
4th position switch signal R T
Tow mode switch signal R T
A/T fluid temperature sensor 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-12
[CAN]
CAN COMMUNICATION
Revision: October 20052005 QX56
Buzzer output signal R T
Fuel level sensor signal R T
ASCD SET lamp signal T R
ASCD CRUISE lamp signal T R
Malfunction indicator lamp signal T R
Fuel level low warning signal T R
Front wiper request signal T R
Front wiper stop position signal R T
Rear window defogger switch signal T R R
Rear window defogger control signal R R R T
Hood switch signal R T
Theft warning horn request signal T R
Horn chirp signal T R
Steering angle sensor signal T R
ABS warning lamp signal R T
VDC OFF indicator lamp signal R T
SLIP indicator lamp signal R T
Brake warning lamp signal R T
System setting signalRT
TR
Distance to empty signal T R
ASCD operation signal T R
ASCD OD cancel request T R
A/T CHECK indicator lamp signal T R
A/T position indicator lamp signal T R R
Tire pressure signal R T
Tire pressure data signal R T
1st position switch signal R T
4th position switch signal R T
Tow mode switch signal R T
A/T fluid temperature sensor signal T RSignals ECM TCMDriver
seat
con-
trol
unitCom-
bina-
tion
meterDis-
play
con-
trol
unitBCMSteer-
ing
angle
sen-
sorFront
air
con-
trolTrans-
fer
con-
trol
unitABS
actua-
tor
and
elec-
tric
unit
(con-
trol
unit)IPDM
E/R
HARNESS
PG-61
C
D
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F
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MA
B
PG
Revision: October 20052005 QX56
HSEAT SE Heated Seat
ICC ACS Intelligent Cruise Control
ICCBOF EC ICC Brake Switch
ICC/BS EC ICC Steering Switch
ICC/SW EC ICC Brake Switch
I/MIRR GW Inside Mirror (Auto Anti-Dazzling Mirror)
IATS EC Intake Air Temperature Sensor
IGNSYS EC Ignition System
ILL LT Illumination
INJECT EC Injector
INT/L LT Room/Map, Vanity, Cargo, Personal, Foot, Step, and Puddle Lamps
KEYLES BL Remote Keyless Entry System
KS EC Knock Sensor
MAFS EC Mass Air Flow Sensor
MAIN EC Main Power Supply and Ground Circuit
METER DI Speedometer, Tachometer, Temp. and Fuel Gauges
MIL/DL EC Malfunction Indicator Lamp
MIRROR GW Door Mirror
NATS BL Nissan Anti-Theft System
NAVI AV Navigation System
O2H2B1 EC Rear Heated Oxygen Sensor 2 Heater Bank 1
O2H2B2 EC Rear Heated Oxygen Sensor 2 Heater Bank 2
O2S2B1 EC Heated Oxygen Sensor 2 Bank 1
O2S2B2 EC Heated Oxygen Sensor 2 Bank 2
P/SCKT WW Power Socket
PGC/V EC EVAP Canister Purge Volume Control Solenoid Valve
PHASE EC Camshaft Position Sensor (PHASE) (Bank 1)
PNP/SW EC Park/Neutral Position Switch
POS EC Crankshaft Position Sensor (POS)
POWER PG Power Supply Routing
PRE/SE EC EVAP Control System Pressure Sensor
PS/SEN EC Power Steering Pressure Sensor
R/VIEW DI Rear View Monitor
RP/SEN EC Refrigerant Pressure Sensor
SEN/PW EC Sensor Power Supply
SHIFT AT A/T Shift Lock System
SONAR DI Rear Sonar System
SROOF RF Sunroof
SRS SRS Supplemental Restraint System
START SC Starting System
STOP/L LT Stop Lamp
T/TOW LT Trailer Tow
T/WARN WT Low Tire Pressure Warning System
TAIL/L LT Parking, License and Tail Lamps
T/F TF Transfer Case
TPS1 EC Throttle Position Sensor
TPS2 EC Throttle Position Sensor
TPS3 EC Throttle Position Sensor
TRNSCV BL HOMELINK® Universal Transceiver
TURN LT Turn Signal and Hazard Warning Lamps
VDC BRC Vehicle Dynamic Control System
VEHSEC BL Vehicle security (theft warning) system
TF-1
TRANSFER
D DRIVELINE/AXLE
CONTENTS
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SECTION TF
A
B
TF
Revision: October 20052005 QX56 PRECAUTIONS .......................................................... 4
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” .................................................................. 4
Precautions for Transfer Assembly and Transfer
Control Unit Replacement ........................................ 4
METHOD FOR POSITION ADJUSTMENT ........... 4
Precautions .............................................................. 4
Service Notice .......................................................... 5
Wiring Diagrams and Trouble Diagnosis .................. 5
PREPARATION ........................................................... 6
Special Service Tools ............................................... 6
Commercial Service Tools ........................................ 9
NOISE, VIBRATION AND HARSHNESS (NVH)
TROUBLESHOOTING .............................................. 10
NVH Troubleshooting Chart ................................... 10
TRANSFER FLUID ....................................................11
Replacement ...........................................................11
DRAINING ............................................................11
FILLING ................................................................11
Inspection ................................................................11
FLUID LEAKAGE AND FLUID LEVEL .................11
ALL-MODE 4WD SYSTEM ...................................... 12
Cross-section View ................................................ 12
Power Transfer ....................................................... 13
POWER TRANSFER DIAGRAM ........................ 13
POWER TRANSFER FLOW ............................... 14
System Description ................................................ 15
CONTROL SYSTEM ........................................... 15
TRANSFER MOTOR .......................................... 16
WAIT DETECTION SWITCH .............................. 17
NEUTRAL-4LO SWITCH .................................... 17
ATP SWITCH ...................................................... 17
2-4WD SHIFT SOLENOID VALVE ...................... 17
CLUTCH PRESSURE SOLENOID VALVE ......... 17
LINE PRESSURE SWITCH ................................ 18
CLUTCH PRESSURE SWITCH .......................... 18
TRANSFER FLUID TEMPERATURE SENSOR ... 18
TRANSFER CONTROL UNIT ............................. 18
TRANSFER CONTROL DEVICE ........................ 184WD SHIFT SWITCH AND INDICATOR LAMP ... 18
4WD WARNING LAMP ....................................... 19
ATP WARNING LAMP ......................................... 19
System Diagram ..................................................... 19
COMPONENTS FUNCTION ............................... 20
CAN Communication .............................................. 20
SYSTEM DESCRIPTION .................................... 20
TROUBLE DIAGNOSIS ............................................ 21
How to Perform Trouble Diagnosis ......................... 21
BASIC CONCEPT ............................................... 21
Location of Electrical Parts ..................................... 22
Circuit Diagram ....................................................... 23
Wiring Diagram — T/F — ....................................... 24
Inspections Before Trouble Diagnosis .................... 32
TRANSFER FLUID CHECK ................................ 32
PREPARATION FOR ROAD TEST ..................... 32
CHECK BEFORE ENGINE IS STARTED ........... 32
CHECK AT IDLE .................................................. 32
CRUISE TEST ..................................................... 34
Trouble Diagnosis Chart for Symptoms .................. 34
Transfer Control Unit Input/Output Signal Refer-
ence Values ............................................................ 36
TRANSFER CONTROL UNIT INSPECTION
TABLE ................................................................. 36
CONSULT-II Function (ALL MODE AWD/4WD) ..... 44
FUNCTION .......................................................... 44
CONSULT-II SETTING PROCEDURE ................ 44
SELF-DIAG RESULT MODE ............................... 45
DATA MONITOR MODE ...................................... 47
WORK SUPPORT ............................................... 49
Self-diagnostic Procedure ...................................... 50
SELF-DIAGNOSTIC PROCEDURE (WITH
CONSULT-II) ....................................................... 50
SELF-DIAGNOSTIC PROCEDURE (WITHOUT
CONSULT-II) ....................................................... 50
ERASE SELF-DIAGNOSIS ................................. 53
TROUBLE DIAGNOSIS FOR SYSTEM .................... 54
Power Supply Circuit For Transfer Control Unit ...... 54
CONSULT-II REFERENCE VALUE IN DATA
MONITOR MODE ................................................ 54
TF-34
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
CRUISE TEST
1. CHECK INPUT SIGNAL
1. Warm up engine to normal operating temperature.
2. Park vehicle on flat surface.
3. Move A/T selector lever to “P” position.
4. Set 4WD shift switch to “AUTO” position.
5. Start engine.
6. Drive vehicle for at least 30 seconds at a speed higher than 20 km/h (12 MPH).
Check 4WD warning lamp turned ON?
On steady>>Perform the self-diagnosis. Refer to TF-50, "SELF-DIAGNOSTIC PROCEDURE (WITH CON-
SULT-II)" (with CONSULT-II) or TF-50, "SELF-DIAGNOSTIC PROCEDURE (WITHOUT CON-
SULT-II)" (without CONSULT-II).
Flash rapidly>>GO TO TF-128, "
4WD Warning Lamp Flashes Rapidly" .
Flash slowly>>GO TO TF-129, "
4WD Warning Lamp Flashes Slowly" .
NO >> GO TO 2.
2. CHECK TIGHT CORNER BRAKING SYMPTOM (1)
1. Set 4WD shift switch to “AUTO” position.
2. Drive vehicle at speed lower than 20 km/h (12 MPH) with steering wheel fully turned.
Does tight corner braking symptom occur?
YES >> GO TO TF-130, "Heavy Tight-corner Braking Symptom Occurs" .
NO >> GO TO 3.
3. CHECK TIGHT CORNER BRAKING SYMPTOM (2)
1. Set 4WD shift switch to “4HI” position.
2. Drive vehicle at speed lower than 20 km/h (12 MPH) with steering wheel fully turned.
Does tight corner braking symptom occur?
YES >> Inspection End.
NO >> GO TO TF-131, "
4WD System Does Not Operate" .
Trouble Diagnosis Chart for SymptomsEDS002HI
If 4WD warning lamp turns ON, perform self-diagnosis. Refer to TF-50, "Self-diagnostic Procedure" .
Symptom Condition Check item Reference page
4WD shift indicator lamp and 4LO indicator
lamp do not turn ON
(4WD shift indicator lamp and 4LO indicator
lamp check)Ignition switch: ONPower supply and ground for transfer
control unit
TF-117
Transfer shut off relay
Combination meter
4WD warning lamp does not turn ON
(4WD warning lamp check)Ignition switch: ONPower supply and ground for transfer
control unit
TF-121
Transfer shut off relay
Combination meter