2001 INFINITI QX4 4WD

Symptom 1. 4WD Shift Indicator Lamp Does
Not Turn ON
NBTF0029SYMPTOM: Although ignition switch is turned ªONº, all the
4WD shift indicator lamps do not turn ON for 1 second.
1 CHECK TRANSFER CONTROL UNIT POWER SOURCE
SMT958D
SMT860D
1. Turn ignition switch to ªOFFº position and disconnect transfer control unit harness connector.
2. Turn ignition switch to ªONº position. (Do not start engine.)
3. Check voltage between transfer control unit harness connector terminals 16, 22 and body ground.
Voltage: Battery voltage
SMT796D
OK or NG
OK©GO TO 2.
NG©Check the following.
IContinuity between ignition switch and transfer control unit
IIgnition switch and No. 18 fuse (10A)
TROUBLE DIAGNOSES FOR SYMPTOMS
Symptom 1. 4WD Shift Indicator Lamp Does Not Turn ON
TF-98

2 CHECK TRANSFER CONTROL UNIT GROUND CIRCUIT
1. Turn ignition switch to ªOFFº position.
2. Disconnect transfer control unit harness connector.
3. Measure resistance between transfer control unit harness connector terminals 6, 45 and body ground.
Resistance: 0W
SMT797D
OK or NG
OK©GO TO 3.
NG©Check continuity between transfer control unit and body ground.
3 CHECK PROCEDURES FROM THE BEGINNING AGAIN
Check again.
OK or NG
OK©INSPECTION END
NG©1. Perform transfer control unit input/output signal inspection. Refer to ªTRANSFER
CONTROL UNIT INSPECTION TABLEº, ªTROUBLE DIAGNOSIS Ð GENERAL
DESCRIPTIONº, TF-55.
2. If NG, recheck transfer control unit pin terminals for damage or loose connection with
harness connector.
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TROUBLE DIAGNOSES FOR SYMPTOMS
Symptom 1. 4WD Shift Indicator Lamp Does Not Turn ON (Cont'd)
TF-99

Symptom 2. 4WD Warning Lamp Does Not Turn
ON
=NBTF0030SYMPTOM: Although ignition switch is turned ªONº, 4WD
warning lamp does not turn ON.
1 CHECK TRANSFER CONTROL UNIT POWER SOURCE
SMT799D
1. Turn ignition switch to ªOFFº position and disconnect transfer control unit harness connector.
2. Turn ignition switch to ªONº position.
(Do not start engine.)
3. Check voltage between transfer control unit harness connector terminals 16, 22 and body ground.
Voltage: Battery voltage
SMT800D
OK or NG
OK©GO TO 2.
NG©Check the following.
IContinuity between ignition switch and transfer control unit
IIgnition switch and No. 18 fuse (10A)
TROUBLE DIAGNOSES FOR SYMPTOMS
Symptom 2. 4WD Warning Lamp Does Not Turn ON
TF-100

2 CHECK TRANSFER CONTROL UNIT GROUND CIRCUIT
1. Turn ignition switch to ªOFFº position.
2. Disconnect transfer control unit harness connector.
3. Measure resistance between transfer control unit harness connector terminals 6, 45 and body ground.
Resistance: 0W
SMT803D
OK or NG
OK©GO TO 3.
NG©Check continuity between transfer control unit and body ground.
3 CHECK 4WD WARNING LAMP CIRCUIT
Check the following.
I4WD warning lamp
IContinuity between ignition switch and 4WD warning lamp
IContinuity between 4WD warning lamp and transfer control unit
OK or NG
OK©GO TO 4.
NG©IRepair or replace harness or connector.
IReplace 4WD warning lamp.
4 CHECK PROCEDURES FROM THE BEGINNING AGAIN
Check again.
OK or NG
OK©INSPECTION END
NG©1. Perform transfer control unit input/output signal inspection. Refer to ªTRANSFER
CONTROL UNIT INSPECTION TABLEº, ªTROUBLE DIAGNOSIS Ð GENERAL
DESCRIPTIONº, TF-55.
2. If NG, recheck transfer control unit pin terminals for damage or loose connection with
harness connector.
GI
MA
EM
LC
EC
FE
AT
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
TROUBLE DIAGNOSES FOR SYMPTOMS
Symptom 2. 4WD Warning Lamp Does Not Turn ON (Cont'd)
TF-101

Symptom 3. 4WD Shift Indicator Lamp Does
Not Turn OFF
NBTF0031SYMPTOM: When 4WD shift switch is set from ª4Hº to
ª4LOº, all the 4WD shift indicator lamps do not turn OFF.
1 CHECK ATP SWITCH CIRCUIT
SMT958D
Check ATP switch circuit.
Refer to ªDiagnostic Procedureº, ªATP SWITCH, WAIT DETECTION SWITCH AND NEUTRAL-4LO SWITCHº, TF-112.
OK or NG
OK©GO TO 2.
NG©Check, repair or replace faulty parts.
2 CHECK PROCEDURE FROM THE BEGINNING AGAIN
Check again.
OK or NG
OK©INSPECTION END
NG©Recheck each connector's pin terminals for damage or loose connection.
SMT856D
Symptom 4. ATP Warning Lamp Does Not Turn
ON
NBTF0032SYMPTOM: When 4WD shift switch is set from ª4Hº to
ª4LOº with A/T selector lever in ªPº position, ATP warning
lamp does not turn ON.
1 CHECK ATP SWITCH CIRCUIT
Check ATP switch circuit.
Refer to ªDiagnostic Procedureº, ªATP SWITCH, WAIT DETECTION SWITCH AND NEUTRAL-4LO SWITCHº, TF-112.
OK or NG
OK©GO TO 2.
NG©Check, repair or replace faulty parts.
TROUBLE DIAGNOSES FOR SYMPTOMS
Symptom 3. 4WD Shift Indicator Lamp Does Not Turn OFF
TF-102

Symptom 5. 4LO Indicator Lamp Does Not Turn
ON
=NBTF0033SYMPTOM: When 4WD shift switch is set from ª4Hº to
ª4LOº position, 4LO indicator lamp does not turn ON.
1 CHECK TRANSFER CONTROL UNIT POWER SUPPLY CIRCUIT
SMT958D
SMT851D
SMT979D
1. Disconnect battery negative terminal (þ), then transfer control unit connector.
2. Connect battery negative terminal (þ) and turn ignition switch ªONº (with engine stopped).
3. Check voltage across transfer control unit body-side connector terminals 47, 16 and body ground.
Voltage: Battery voltage
OK or NG
OK©GO TO 2.
NG©Check the following.
IContinuity between battery and transfer control unit
IIgnition switch (Refer to EL-9, ªPower Supply Routingº.)
INo. 24 fuse (7.5A), No. 8 fuse (10A) and No. 18 fuse (10A)
TROUBLE DIAGNOSES FOR SYMPTOMS
Symptom 5. 4LO Indicator Lamp Does Not Turn ON
TF-104

Symptom 6. 4WD Shift Indicator Lamp Does
Not Indicate ª4Hº
NBTF0034SYMPTOM: When 4WD shift switch is set to ª4Hº, 4WD shift
indicator lamp does not indicate ª4Hº.
1 CHECk 4WD WARNING LAMP
SMT958D
Is 4WD warning lamp turned ON?
YesorNo
Ye s©Refer to ªTrouble Diagnosis without CONSULT-IIº, TF-27.
No©GO TO 2.
2 CHECK FOLLOWING ITEMS
Check the following.
INeutral-4LO switch circuit. Refer to TF-76.
IWait detection switch circuit. Refer to TF-76.
IATP switch circuit. Refer to TF-76.
OK or NG
OK©GO TO 3.
NG©Check, repair or replace faulty parts.
3 CHECK PROCEDURES FROM THE BEGINNING AGAIN
Check again.
OK or NG
OK©INSPECTION END
NG©Recheck each connector's pin terminals for damage or loose connection.
TROUBLE DIAGNOSES FOR SYMPTOMS
Symptom 6. 4WD Shift Indicator Lamp Does Not Indicate ª4Hº
TF-106

Symptom 7. 4WD Shift Indicator Lamp Repeats
Flickering
=NBTF0035SYMPTOM: 4WD shift indicator lamp keeps flickering.
1 CHECK 4WD SHIFT INDICATOR LAMP
SMT958D
1. Set 4WD shift switch to ª2WDº position.
2. Move vehicle forward and backward. Or drive straight increasing or decreasing speed under 20 km/h (12 MPH).
3. Does 4WD shift indicator lamp keep flickering?
YesorNo
Ye s©GO TO 2.
No©INSPECTION END
2 CHECK TIGHT CORNER BRAKING SYMPTOM
Drive vehicle at speed under 20 km/h (12 MPH), turning steering wheel to the limit. Does tight corner braking symptom
occur?
YesorNo
Ye s©GO TO 3.
No©GO TO 4.
3 CHECK 4WD SHIFT INDICATOR LAMP
Does the 4WD shift indicator lamp keep flickering when the front wheels are jacked up?
YesorNo
Ye s©Check transfer unit operating system.
No©Check tires.
4 CHECK 4WD WARNING LAMP
Does 4WD warning lamp flicker? (4WD shift indicator lamp is turned OFF.)
YesorNo
Ye s©Perform self-diagnoses. Refer to ªTrouble Diagnosis without CONSULT-IIº, TF-27.
No©GO TO 5.
5 CHECK 4WD SHIFT INDICATOR LAMP
Does 4WD shift indicator lamp keep flickering?
YesorNo
Ye s©Check again.
No©INSPECTION END
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TROUBLE DIAGNOSES FOR SYMPTOMS
Symptom 7. 4WD Shift Indicator Lamp Repeats Flickering
TF-107