2001 INFINITI QX4 engine

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

Indicated items
(Screen terms for CONSULT, ªDATA
MONITORº mode)Display Conditions
Clutch pressure switch
(CL PRES SW)OFFIgnition switch in ªONº, and 4WD shift switch in ª2WDº.
(ªWaitº function is not operating.)
ONIgnition switch in ªONº, and 4WD shift switch in ªAUTOº
or ª4Hº and A/T selector lever in ªDº. (ªWaitº function is
not operating.)
Control torque
(COMP CL TORQ)0 kg-m
4WD shift switch
(ªWaitº function is not oper-
ating.)In ª2WDº position
39 - 1,079 N´m
(4 - 110 kg-m, 29 - 796 ft-lb)In ªAUTOº position
1,079 N´m
(110 kg-m, 796 ft-lb)In ª4Hº or ª4LOº position
4WD solenoid
(DUTY SOLENOID)4% In ª2WDº position
94 - 4% In ªAUTOº position
4% In ª4Hº or ª4LOº position
2-4WD shift solenoid valve
(2-4WD SOL)OFF
4WD shift switchIn ª2WDº position
ON (ªWaitº function is not oper-
ating.)
In ªAUTOº position
OFF (ªWaitº function is operat-
ing.)
ON (ªWaitº function is not oper-
ating.)
In ª4Hº position
OFF (ªWaitº function is operat-
ing.)
ON In ª4LOº position
Indicated items Display Conditions
Battery voltage Approx. 12V Key switch ªONº and engine at rest
Approx. 13 - 14V During idling
AUTO switch OFF 4WD shift switch in other than ªAUTOº position
ON 4WD shift switch in ªAUTOº position
4L switch OFF 4WD shift switch in other than ª4LOº position
ON 4WD shift switch in ª4LOº position
N position switch OFF A/T selector lever in other than ªNº position
ON A/T selector lever in ªNº position
R position swtich OFF A/T selector lever in other than ªRº position
ON A/T selector lever in ªRº position
P position switch OFF A/T selector lever in other than ªPº position
ON A/T selector lever in ªPº position
Throttle opening 0.0/8 - 8.0/8 Throttle fully closed (0.0/8) or throttle fully open (8.0/8)
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ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Trouble Diagnosis with CONSULT-II (Cont'd)
TF-37

Indicated items Display Conditions
4WD-mode2WD
4WD shift switchIn ª2WDº position
AUTO In ªAUTOº position
LOCK In ª4Hº position
4L In ª4LOº position
Front wheel speed 0 - 255 km/h (0 - 158 MPH) 0 km/h (vehicle at standstill)
Rear wheel speed 0 - 255 km/h (0 - 158 MPH) 0 km/h (vehicle at standstill)
Shift ACTR operating 1,
Shift activating monitor 1OFF During normal operation
ON During shifts from ª4Hº to ª4LOº position
Shift ACTR operating 2,
Shift activating monitor 2OFF During normal operation
ON During shifts from ª4LOº to ª4Hº position
4WD fail lamp OFF During normal operation
ONDuring 2-second period (after key switch turned to ªONº) or
when system is out of order
Shift ACTR position sensing
switch 1OFF 4WD shift switch is in a position other than ª4LOº.
ON 4WD shift switch in ª4LOº position
Shift ACTR position sensing
switch 2OFF 4WD shift switch in ª4LOº position
ON 4WD shift switch is in a position other than ª4LOº.
2WD indicator lamp OFF Engine at rest or system out of order
ON Except the above condition
AUTO indicator lamp
OFFEngine at rest during 2WD-mode operation or system out of
order
ON4WD shift switch in ª4LOº or ª4Hº position and A/T selector
lever in ªAUTOº position
LOCK indicator lamp
OFFEngine at rest and A/T selector lever in ªAUTOº position during
2WD-mode operation or system out of order
ON 4WD shift switch in ª4Hº or ª4LOº position
4L indicator lamp
OFFEngine at rest and A/T selector lever in ªAUTOº position during
2WD-mode operation or system out of order
ON 4WD shift switch in ª4LOº position
WORK SUPPORTNBTF0012S06PurposeNBTF0012S0601When there is no problem with transfer and 4WD system, follow-
ing symptoms in ªAUTOº mode may be claimed by a customer.
ITight corner braking symptom after accelerator (throttle) open-
ing (Note 1)
IVibration when accelerating on a low  road (snow-covered or
icy road) (Note 2)
It is possible to deal with these symptoms by changing
ªCLUTCH FORCE RELEASE LIMIT VALUEº. However, be
careful when changing the values because it may adversely
affect driving performance.
NOTE:
1) When the accelerator is slightly open (approx. 1/8) or fully
closed after being opened. The tight corner braking symptom
during idle creep driving with accelerator fully closed cannot be
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Trouble Diagnosis with CONSULT-II (Cont'd)
TF-38

IntroductionNBTF0013DESCRIPTIONNBTF0013S01When a malfunction (indicated by the 4WD warning lamp illumination) occurs, collect information first from the
customer about how the malfunction occurs. Then, proceed with the diagnosis presuming it is the cause. Also
inspect the electrical system, paying close attention to other possibilities such as fluid level and leaks.
All-mode 4WD transfer is controlled by transfer control unit and sensors.
If a malfunction occurs in the all-mode 4WD system, the 4WD warning lamp lights up to inform of the system
malfunction. There are two ways to identify the cause of the malfunction.
1) Performing the self-diagnosis. (The 4WD warning lamp will indicate what kind of malfunction has occurred
by flickering.)
2) Performing diagnosis using CONSULT-II.
DIAGNOSTIC WORKSHEETNBTF0013S02Information from CustomerNBTF0013S0201KEY POINTS
WHAT..... Vehicle model
WHEN..... Date, Frequencies
WHERE..... Road conditions
HOW..... Operating conditions, Symptoms
Information sheet from customer
Customer name MR/MS Model & Year VIN
Transfer model
ATX14AEngine Mileage
Incident Date Manuf. Date In Service Date
FrequencylContinuouslIntermittent ( times a day)
Symptomsl4WD shift indicator lamp does not turn on.
l4WD warning lamp does not turn on.
l4WD shift indicator lamp does not turn off.
lATP warning lamp does not turn on.
l4LO indicator lamp does not turn on.
l4WD shift indicator lamp does not indicate ª4Hº.
l4WD shift indicator lamp repeats flicking.
lTight corner braking symptom occurs.
l4WD system does not operate.
lOthers.
4WD warning lamplContinuously litlNot lit
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TROUBLE DIAGNOSIS Ð INTRODUCTION
Introduction
TF-41

Diagnostic WorksheetNBTF0013S0202
1.lListen to customer complaints.TF-44
2.lCheck transfer fluid.TF-44
lLeakage
lFluid condition
lFluid level
3.lRoad testingTF-44
l1. Check before engine is started.
l2. Check at idle.
l3. Cruise test
4.lPerform self-diagnosis NG items (with CONSULT-II and without CONSULT-II). TF-30, TF-27
5.lCheck component. Repair or replace the damaged parts. TF-111
6.lPerform final check. Perform road test (1 through 3). TF-44
TROUBLE DIAGNOSIS Ð INTRODUCTION
Introduction (Cont'd)
TF-42