2001 INFINITI QX4 IDX

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

Work Flow=NBTF0014HOW TO PERFORM TROUBLE DIAGNOSES FOR QUICK AND ACCURATE REPAIRNBTF0014S01A good understanding of the malfunction conditions can make troubleshooting faster and more accurate.
In general, each customer feels differently about a problem. It is important to fully understand the symptoms
or conditions for a customer complaint.
Make good use of the two sheets provided, ªInformation from Customerº (Refer to TF-41.) and ªDiagnostic
Worksheetº (Refer to TF-42.), to perform the best troubleshooting possible.
MTF013A
*1: TF-44
*2: TF-44*3: TF-44
*4: TF-98 - TF-109*5: TF-61 - TF-94
*6: TF-44
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TROUBLE DIAGNOSIS Ð INTRODUCTION
Work Flow
TF-43

1. CHECK BEFORE ENGINE IS STARTED=NBTF0017S02
1 CHECK 4WD SHIFT INDICATOR LAMP
1. Park vehicle on flat surface.
2. Turn ignition switch to ªOFFº position.
3. Move A/T selector lever to ªPº position.
4. Set 4WD shift switch to ª4Hº position.
SMT849D
5. Set 4WD shift switch to ª2WDº position.
6. Turn ignition switch to ªONº position. (Do not start engine.)
7. Does 4WD shift indicator lamp turn ON for approx. 1 second?
SMT958D
YesorNo
Ye s©GO TO 2.
No©Go to Symptom 1. Refer to TF-98.
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TROUBLE DIAGNOSIS Ð BASIC INSPECTION
Road Test (Cont'd)
TF-45

2. CHECK AT IDLE=NBTF0017S03
1 CHECK 4WD SHIFT INDICATOR LAMP
1. Park vehicle on flat surface.
2. Turn ignition switch to ªOFFº position.
3. Move A/T selector lever to ªPº or ªNº position.
4. Set 4WD shift switch to ª4Hº position.
5. Set 4WD shift switch to ª2WDº position.
6. Start engine.
7. Is 4WD shift indicator lamp turned OFF?
SMT958D
YesorNo
Ye s©Go to ªATP SWITCH, WAIT DETECTION SWITCH AND NEUTRAL-4LO SWITCHº. Refer
to TF-76.
No©GO TO 2.
2 CHECK 4WD WARNING LAMP
Is 4WD warning lamp turned OFF?
YesorNo
Ye s©GO TO 3.
No©Perform self-diagnosis. Refer to ªTrouble Diagnosis without CONSULT-IIº, TF-27.
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TROUBLE DIAGNOSIS Ð BASIC INSPECTION
Road Test (Cont'd)
TF-47

5 CHECK 4WD SHIFT INDICATOR LAMP
1. Move A/T selector lever to ªPº position.
2. Set 4WD shift switch from ª4Hº to ª4LOº.
SMT849D
3. While shifting from ª4Hº to ª4LOº, does 4WD shift indicator lamp turn OFF and ATP warning lamp turn ON?
SMT958D
YesorNo
Ye s©GO TO 6.
No©Go to Symptoms 3 and 4. Refer to TF-102.
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TROUBLE DIAGNOSIS Ð BASIC INSPECTION
Road Test (Cont'd)
TF-49

3. CRUISE TEST=NBTF0017S04
1 INSPECTION START
SMT849D
SMT958D
WITH CONSULT-II©GO TO 2.
WITHOUT CONSULT-II©GO TO 3.
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TROUBLE DIAGNOSIS Ð BASIC INSPECTION
Road Test (Cont'd)
TF-51

5 CONFIRM SYMPTOM AGAIN
Confirm symptom and self-diagnosis again.
Refer to ªTrouble Diagnosis without CONSULT-IIº, TF-27 and ªTrouble Diagnosis with CONSULT-IIº, TF-30.
OK or NG
OK©GO TO 6.
NG©Go to Symptoms 8 and 9. Refer to TF-108, 109.
6 (2) CHECK TIGHT CORNER BRAKING SYMPTOM
1. Set 4WD shift switch to ª4Hº position.
2. Drive vehicle at speed lower than 20 km/h (12 MPH) with steering wheel fully turned.
3. Does tight corner braking symptom occur?
YesorNo
Ye s©INSPECTION END
No©GO TO 7.
7 CONFIRM SYMPTOM AGAIN
Confirm symptom and self-diagnosis again.
Refer to ªTrouble Diagnosis without CONSULT-IIº, TF-27 and ªTrouble Diagnosis with CONSULT-IIº, TF-30.
OK or NG
OK©INSPECTION END
NG©Go to Symptoms 8 and 9. Refer to TF-108, 109.
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TROUBLE DIAGNOSIS Ð BASIC INSPECTION
Road Test (Cont'd)
TF-53

SMT772D
TRANSFER CONTROL UNIT INSPECTION TABLENBTF0018S02(Data are reference values.)
Terminal
No.Item Condition Judgement standard
12-4WD shift solenoid
valve
&
4WD shift switch is set to ª2WDº
position.Less than 1V
4WD shift switch is set to any posi-
tion other than ª2WDº.Battery voltage
24WD shift indicator lamp
(2WD)
Lamp lights while system is operating
properly.Less than 1V
&
2WD indicator lamp does not come
on.Battery voltage
3 Ground Ð Ð
4Transfer shift relay
(High)While actuator is operating
(4H,4LO)Battery voltage
Actuator does not operate. Less than 1V
5 4WD warning lampLamp comes ON. (when engine is
stopped.)
(Fail-safe condition appears on
display, engine is stopped, actuator
position detection switch is
inoperative, oil temperature is too
high and/or tires of different size are
installed.)Less than 1V
Except above Battery voltage
6 Ground Ð Ð Ð
7 PNP switch (R position)
&
A/T selector lever is set to ªreverseº
position.Battery voltage
A/T selector lever is set to any posi-
tion other than ªreverseº.Less than 1V
8ÐÐÐÐ
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TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
Transfer Control Unit Terminals and Reference Value (Cont'd)
TF-55