engine INFINITI QX4 2001 Factory Service Manual

WHEELARCH HEIGHT (UNLADEN*)NBSU0019Unit: mm (in)
SFA746B
Applied model 245/70 R16 tire 245/65 R17 tire
Front (Hf)794 (31.26)
Rear (Hr)810 (31.89)
*: Fuel, radiator coolant and engine oil full. Spare tire, jack, hand tools and mats in designated positions.
WHEEL RUNOUT AVERAGE*NBSU0020Unit: mm (in)
Radial runout limit0.3 (0.012)
Lateral runout limit0.3 (0.012)
*: Wheel runout average = (Outside runout value + Inside runout value) x 0.5
FRONT SUSPENSION
Service Data and Specifications (SDS) (Cont'd)
SU-14

SBR686C
Precautions
PRECAUTIONSNBSU0021IWhen installing rubber parts, final tightening must be car-
ried out under unladen condition* with tires on ground.
*Fuel, radiator coolant and engine oil full. Spare tire, jack,
hand tools and mats in designated positions.
IUse flare nut wrench when removing and installing brake
tubes.
IAfter installing removed suspension parts, check wheel
alignment and adjust if necessary.
IAlways torque brake lines when installing.
Preparation
COMMERCIAL SERVICE TOOLSNBSU0023
Tool name Description
1 Flare nut crowfoot
2 Torque wrench
NT360
Removing and installing each brake piping
a: 10 mm (0.39 in)
Noise, Vibration and Harshness (NVH)
Troubleshooting
NBSU0036Refer to ªNoise, Vibration and Harshness (NVH) Troubleshootingº,
ªFRONT SUSPENSIONº, SU-3.
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REAR SUSPENSION
Precautions
SU-15

TRANSFER
SECTION
TF
CONTENTS
PRECAUTIONS...............................................................3
Supplemental Restraint System (SRS)²AIR
BAG²and²SEAT BELT PRE-TENSIONER²...............3
Precautions ..................................................................3
Service Notice..............................................................4
Wiring Diagrams and Trouble Diagnosis .....................4
PREPARATION...............................................................5
Special Service Tools ..................................................5
Commercial Service Tools ...........................................9
ALL-MODE 4WD SYSTEM...........................................10
Cross-sectional View .................................................10
Control System .......................................................... 11
ALL-MODE 4WD TRANSFER BASIC CONTROL........12
HYDRAULIC CONTROL CIRCUITS...........................12
OUTLINE................................................................12
CONTROL SYSTEM DIAGRAM................................13
INDICATIONS OF 4WD WARNING LAMP..................13
Location of Electrical Parts ........................................14
Description of Electrical Parts ...................................15
TRANSFER MOTOR................................................15
WAIT DETECTION SWITCH.....................................15
2-4WD SHIFT SOLENOID VALVE.............................16
LINE PRESSURE SWITCH.......................................16
Circuit Diagram for Quick Pinpoint Check.................17
Wiring Diagram - TF -................................................18
ON BOARD DIAGNOSTIC SYSTEM
DESCRIPTION...............................................................27
Trouble Diagnosis without CONSULT-II ....................27
DESCRIPTION........................................................27
SELF-DIAGNOSTIC PROCEDURE............................28
INDICATIONS OF 4WD WARNING LAMP..................29
Trouble Diagnosis with CONSULT-II .........................30
SELF-DIAGNOSIS...................................................30
SELF-DIAGNOSTIC ITEMS......................................31
DATA MONITOR......................................................33
DATA MONITOR ITEMS...........................................34
REFERENCE VALUE IN DATA MONITOR MODE......36
WORK SUPPORT....................................................38
CLUTCH FORCE RELEASE LIMIT ADJUSTMENT.....39
TROUBLE DIAGNOSIS - INTRODUCTION..................41Introduction ................................................................41
DESCRIPTION........................................................41
DIAGNOSTIC WORKSHEET.....................................41
Work Flow ..................................................................43
HOW TO PERFORM TROUBLE DIAGNOSES FOR
QUICK AND ACCURATE REPAIR
.............................43
TROUBLE DIAGNOSIS - BASIC INSPECTION...........44
Listen to Customer Complaints .................................44
Transfer Fluid Check .................................................44
Road Test...................................................................44
PREPARATION FOR ROAD TEST............................44
1. CHECK BEFORE ENGINE IS STARTED...............45
2. CHECK AT IDLE..................................................47
3. CRUISE TEST.....................................................51
TROUBLE DIAGNOSIS - GENERAL
DESCRIPTION...............................................................54
Transfer Control Unit Terminals and Reference
Value ..........................................................................54
REMOVAL AND INSTALLATION OF TRANSFER
CONTROL UNIT
......................................................54
INSPECTION OF TRANSFER CONTROL UNIT..........54
TRANSFER CONTROL UNIT INSPECTION TABLE....55
VEHICLE SPEED SENSOR (FRONT
REVOLUTION SENSOR)..............................................61
Diagnostic Procedure ................................................61
4WD SOLENOID VALVE...............................................64
Diagnostic Procedure ................................................64
2-4WD SHIFT SOLENOID VALVE AND 4WD
SHIFT SWITCH..............................................................66
Diagnostic Procedure ................................................66
TRANSFER MOTOR AND TRANSFER MOTOR
RELAY...........................................................................70
Diagnostic Procedure ................................................70
TRANSFER FLUID TEMPERATURE SENSOR............73
Diagnostic Procedure ................................................73
ATP SWITCH, WAIT DETECTION SWITCH AND
NEUTRAL-4LO SWITCH...............................................76
Diagnostic Procedure ................................................76
CLUTCH PRESSURE SWITCH....................................80
Diagnostic Procedure ................................................80
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CONTROL SYSTEM DIAGRAMNBTF0007S04
SMT763D
INDICATIONS OF 4WD WARNING LAMPNBTF0007S05
Condition Content 4WD warning lamp
During self-diagnosis Indicates the malfunction position by number of flickers. Flickers at malfunction mode.
Lamp check*Checks the lamp by turning ON during engine starting. After
engine starts, it turns OFF if there are no malfunctions.ON
Malfunction in 4WD system*Turns ON to indicate malfunction. When ignition switch is
turned to ªOFFº or the malfunction is corrected, it turns OFF.ON
When vehicle is driven with different
diameters of front and rear tiresFlickers once every 2 seconds.
Turns OFF when ignition switch is ªOFFº.Flickers once every 2 sec-
onds.
High fluid temperature in transfer
unitWhen fluid temperature is high or fluid temperature sensor
circuit is shorted, it flickers twice every second.
It turns OFF when fluid temperature becomes normal.Flickers twice a second.
Other than above (System is nor-
mal.)Lamp is OFF. OFF
*: When 4WD warning lamp is ON, all the 4WD shift indicator lamps turn OFF.
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ALL-MODE 4WD SYSTEM
Control System (Cont'd)
TF-13

Trouble Diagnosis without CONSULT-IINBTF0011DESCRIPTIONNBTF0011S01If the engine starts when there is something wrong with the all-
mode 4WD system, the 4WD warning lamp turns ON or flickers in
the combination meter. When the system functions properly, the
warning lamp turns ON when the ignition switch is turned to ªONº,
and it turns OFF after engine starts.
To locate the cause of a problem, start the self-diagnosis function.
The 4WD warning lamp in the combination meter will indicate the
problem area by flickering according to the self-diagnostic results.
As for the details of the 4WD warning lamp flickering patterns, refer
to TF-29.GI
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ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Trouble Diagnosis without CONSULT-II
TF-27

INDICATIONS OF 4WD WARNING LAMPNBTF0011S03
Flickering pattern or flick-
ering conditionMalfunction Check items
1 Front revolution sensor circuit is shorted or open.Revolution sensor (front) circuit,
TF-61.
2 Rear revolution sensor circuit is shorted or open.Revolution sensor (rear) [Refer to
AT-111, ªDTC P0720 Vehicle Speed
Sensor´A/T (Revolution sensor)º.]
3 4WD solenoid valve circuit is shorted or open. 4WD solenoid valve circuit, TF-64.
42-4WD shift solenoid valve circuit is shorted or 2WD switch of
4WD shift switch is shorted.2-4WD shift solenoid valve circuit or
4WD shift switch circuit, TF-66.
5 Transfer motor relay circuit is shorted or open. Transfer motor relay circuit, TF-70.
8Power supply voltage of throttle position sensor is improper. Or
A/D converter of transfer control unit functions improperly.Throttle position sensor (Refer to
AT-176, ªDTC P1705 Throttle Posi-
tion Sensorº.)
9 Transfer fluid temperature sensor circuit is open.Transfer fluid temperature sensor
circuit, TF-73.
10 Neutral-4LO switch circuit is shorted or open. Neutral-4LO switch circuit, TF-76.
112-4WD shift solenoid valve circuit, 2WD switch of 4WD shift
switch circuit or clutch pressure switch circuit is shorted or open.2-4WD shift solenoid valve circuit,
4WD shift switch circuit or clutch
pressure switch circuit, TF-66, 80.
12 Line pressure switch circuit is shorted or open. Line pressure switch circuit, TF-83.
13 Engine speed signal circuit is shorted or open.Engine speed signal (Refer to
AT-116, ªDTC P0725 Engine Speed
Signalº.)
14 Throttle position sensor circuit is shorted or open.Throttle position sensor (Refer to
AT-176, ªDTC P1705 Throttle Posi-
tion Sensorº.)
15 Failure in power supply circuit of transfer control unit. Power supply of transfer control unit
16 4WD shift switch circuit is shorted. 4WD shift switch circuit, TF-66.
17 ABS operation signal circuit is shorted. ABS operation signal circuit, TF-86.
18ATP switch, wait detection switch or neutral-4LO switch circuit is
shorted or open.ATP switch, wait detection switch or
neutral-4LO switch circuit*, TF-76.
19Transfer control device actuator motor is faulty. (Abnormalities
are detected when actuator motor fails to operate while shifting
from ª4Hº to ª4LOº or vice versa.)Actuator motor and motor circuit,
TF-115, 89.
20Transfer control device actuator motor arm position sensing
switch is faulty.Actuator motor arm position sensing
switch and sensing switch circuit,
TF-115, 92.
21Transfer control device actuator circuit is faulty (Abnormalities
are detected when motor relay circuit is open/shorted or relay
monitor circuit is open/shorted.)Actuator motor, actuator motor arm
position sensing switch and their
associated circuits, TF-114, 115 and
94.
Repeats flickering every
2 to 5 sec.Circuits that the self-diagnosis covers have no malfunction. Ð
Repeats flickering every
0.25 sec.IPower supply failure of memory back-up.
IBattery is disconnected for a long time.
IBattery performance is poor.Data erase/display circuit, TF-88.GI
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ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Trouble Diagnosis without CONSULT-II (Cont'd)
TF-29

Flickering pattern or flick-
ering conditionMalfunction Check items
No flickering PNP switch or 4WD shift switch circuit is shorted or open.PNP switch (Refer to AT-99, ªDTC
P0705 Park/Neutral Position
Switchº.) or 4WD shift switch circuit,
TF-66.
*: If revolution sensor malfunction is simultaneously detected, check revolution sensor first.
SAT601J
Trouble Diagnosis with CONSULT-IINBTF0012SELF-DIAGNOSISNBTF0012S01CONSULT-II Setting ProcedureNBTF0012S01011. Turn ignition switch to ªOFFº position.
SMT962D
2. Connect CONSULT-II to data link connector which is located
in instrument lower panel on driver side.
SAT586J
3. Start engine.
4. On CONSULT-II screen, touch ªSTARTº.
SMT964D
5. Touch ªALL MODE 4WDº on SELECT SYSTEM screen.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Trouble Diagnosis without CONSULT-II (Cont'd)
TF-30

SMT965D
6. Touch ªSELF-DIAG RESULTSº on SELECT DIAG MODE
screen.
SMT966D
7. Self-diagnostic results are displayed.
SELF-DIAGNOSTIC ITEMSNBTF0012S02
Detected items
(Screen terms for CONSULT-II,
ªSELF-DIAG RESULTº mode)Malfunction is detected when... Check items
Revolution sensor (front) (Note 3)
(VHCL SPEED SEN´FR)IFront revolution sensor (installed on T/F) signal is not
input due to open circuit.
IImproper signal is input while driving.Revolution sensor (front) circuit,
TF-61.
Revolution sensor (rear)
(VHCL SPEED SEN´RR)ISignal from vehicle speed sensor 1 (installed on A/T)
is not input due to open circuit.
IImproper signal is input while driving.Revolution sensor (rear) [Refer to
AT-111, ªDTC P0720 Vehicle Speed
Sensor´A/T (Revolution sensor)º.]
4WD solenoid valve
(DUTY SOLENOID)
IProper voltage is not applied to solenoid valve due to
open or short circuit.4WD solenoid valve, TF-64.
2-4WD shift solenoid valve
(2-4WD SOLENOID)2-4WD shift solenoid valve or
4WD shift switch circuit, TF-66.
Transfer motor relay
(MOTOR RELAY)IMotor does not operate properly due to open or short
circuit in transfer motor or motor relay.Transfer motor relay circuit,
TF-70.
Transfer fluid temperature sensor
(FLUID TEMP SENSOR)ISignal voltage from fluid temperature sensor is abnor-
mally high (T/F fluid temperature is abnormally low)
while driving.Transfer fluid temperature sensor
circuit, TF-73.
Neutral-4LO switch
(N POSI SW TF)IImproper signal is input while driving. Neutral-4LO switch, TF-76.
Clutch pressure
(CLUTCH PRESSURE)IImproper signal is input due to open or short circuit.
IMalfunction occurs in clutch pressure hydraulic circuit.Clutch pressure switch circuit
(*1), TF-80.
Line pressure
(LINE PRESSURE)IImproper signal is input due to open or short circuit.
IMalfunction occurs in line pressure hydraulic circuit.Line pressure switch circuit (*1),
TF-83.
Engine speed signal (Note 1)
(ENGINE SPEED SIG)IEngine speed is abnormally low while driving.Engine speed signal (Refer to
AT-116, ªDTC P0725 Engine Speed
Signalº.)
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ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Trouble Diagnosis with CONSULT-II (Cont'd)
TF-31

SMT963D
12. Monitored data are displayed.
DATA MONITOR ITEMSNBTF0012S04q: StandardH: Option
Item [Unit]Monitor item
Remarks
ECU input
signalsMain sig-
nalsItem menu
selection
Revolution sensor-front [km/h (MPH)]qHRevolution sensor installed on T/F
Revolution sensor-rear [km/h (MPH)]qHVehicle speed sensor´A/T
Engine speed [rpm]qH
Throttle position sensor [V]qH
Transfer fluid temperature sensor [V]qH
Battery voltage [V]qH
2WD switch [ON-OFF]qH2WD switch of 4WD shift switch
AUTO switch [ON-OFF]qHAUTO switch of 4WD shift switch
Lock switch [ON-OFF]qH4H switch of 4WD shift switch
4L switch [ON-OFF]qH4LO switch of 4WD shift switch
N position switch TF [ON-OFF]qHN position switch of transfer
Line pressure switch [ON-OFF]qHLine pressure switch
Clutch pressure switch [ON-OFF]qHClutch pressure switch
ATP switch [ON-OFF]qH
N position switch [ON-OFF]qHªNº position on A/T PNP switch
R position switch [ON-OFF]qHªRº position on A/T PNP switch
P position switch [ON-OFF]qHªPº position on A/T PNP switch
Closed throttle position switch
[ON/OFF]qHIdle contact of throttle position switch
ABS operation switch [ON-OFF]qHABS operation switch
Wait detection switch [ON-OFF]qH
Throttle openingqHThrottle opening recognized by transfer control
unit
4WD-modeqH4WD-mode recognized by transfer control unit
(2W, AUTO, 4H & 4LO)
Vehicle speed comp [km/h (MPH)]qHVehicle speed recognized by transfer control
unit
*Control torque [N´m (kg-m, ft-lb)]qHCalculated torque recognized by transfer control
unit
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Trouble Diagnosis with CONSULT-II (Cont'd)
TF-34

REFERENCE VALUE IN DATA MONITOR MODENBTF0012S09
Indicated items
(Screen terms for CONSULT, ªDATA
MONITORº mode)Display Conditions
Throttle position sensor
(THRTL POS SEN)Approx. 0.5 - 4.0V Throttle valve fully closed to fully open
Transfer fluid temperature sensor
(FLUID TEMP SE)Approx. 1.5 - 0.5VTransfer fluid temperature approx. 20 - 80ÉC (68 -
176ÉF)
Closed throttle position switch
(CLOSED THL/SW)ON After engine warm-up, accelerator pedal is released.
OFF After engine warm-up, accelerator pedal is depressed.
ABS operation switch
(ABS OPER SW)OFF ABS is not operating.
ON ABS is operating.
ABS control operation
(ABS CONT OPER)ONABS OPER SW is ªONº. Control operation is accom-
plished in combination with ABS.
OFFABS is not operating. When a message such as
ªimproper ABS operation signalº appears on the display
and ABS OPER SW is ªONº, control operation is not
accomplished in combination with ABS.
2WD position
(2WD SW)ON 4WD shift switch is in ª2WDº.
OFF Except the above condition
Lock position
(LOCK SWITCH)ON 4WD shift switch is in ª4Hº.
OFF Except the above condition
Neutral-4LO switch
(N POSI SW TF)
ATP switch
(ATP SWITCH)
Wait detection switch
(WAIT DETCT SW)4WD shift switch position2WD, AUTO,
4H(N) 4LO
ATP switch OFF ON OFF
Neutral-4LO switch OFF ON
Wait detection switchOFF ON
See Note.
Note: When shifting from ª4LOº to ª2WDº, ªAUTOº, ª4Hº, it turns ON when ªWaitº function
is operating (and it turns OFF when ªWaitº function is canceled).
Transfer motor relay
(MOTOR RELAY)Throttle valve4WD shift
switchA/T selector
leverMotor relay Remarks
Fully closed2WD Ð OFF
AUTO,
4LOP, N OFF
ON for approx. 2 sec. after
shifting to ªPº and ªNº
Others ON
4HP OFF
ON for approx. 2 sec. after
shifting to ªPº
Others ON
Line pressure switch
(LINE PRES SW)OFFThe vehicle has been left at room temperature for 5 min-
utes and more with ignition switch in ªOFFº position.
ONIgnition switch in ªONº, and 4WD shift switch in ªAUTOº
or ª4Hº and A/T selector lever in ªDº.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Trouble Diagnosis with CONSULT-II (Cont'd)
TF-36