2001 INFINITI QX4 ignition

2 CHECK 4WD WARNING LAMP
Is 4WD warning lamp turned ON?
SMT958D
YesorNo
Ye s©1. Turn ignition switch to ªOFFº position.
2. Perform self-diagnosis.
Refer to ªTrouble Diagnosis without CONSULT-IIº, TF-27.
3. Go to ª2. CHECK AT IDLEº. Refer to TF-47.
No©Go to Symptom 2. Refer to TF-100.
TROUBLE DIAGNOSIS Ð BASIC INSPECTION
Road Test (Cont'd)
TF-46

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

SMT862D
Transfer Control Unit Terminals and Reference
Value
NBTF0018REMOVAL AND INSTALLATION OF TRANSFER
CONTROL UNIT
NBTF0018S03RemovalNBTF0018S03011. Turn ignition switch OFF and disconnect negative battery ter-
minal.
2. Remove console box.
3. Remove cluster lid C.
4. Remove audio assembly and A/C control unit.
5. Remove instrument lower panel on driver side.
6. Remove glove box.
7. Remove instrument lower panel on passenger side.
8. Remove instrument lower center panel.
9. Remove transfer control unit.
IFor steps 2 through 8 above, refer to BT-21, ªInstrument Panel
Assemblyº.
InstallationNBTF0018S0302IInstallation is in the reverse order of removal.
When installing transfer control unit, tighten transfer control unit
lock nut.
Tightening torque:
: 4.3 - 5.8 N´m (0.44 - 0.59 kg-m, 38 - 51 in-lb)
SMT771D
INSPECTION OF TRANSFER CONTROL UNITNBTF0018S01IMeasure voltage between each terminal and terminal 6 or 45
by following ªTRANSFER CONTROL UNIT INSPECTION
TABLEº, TF-55.
IPin connector terminal layout
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
Transfer Control Unit Terminals and Reference Value
TF-54

Terminal
No.Item Condition Judgement standard
9 4WD shift switch (2WD)
&
4WD shift switch is set to ª2WDº
position.Battery voltage
4WD shift switch is set to any posi-
tion other than ª2WDº.Less than 1V
10Transfer dropping resis-
tor4WD shift switch is set to ªAUTOº
position.Approx.4-14V
4WD shift switch is set to any posi-
tion other than ª2WDº.Less than 1V
114WD shift indicator lamp
(4H)
ª4Hº indicator lamp comes ON. Less than 1V
4WD shift switch is set to any posi-
tion other than ª4Hº.Battery voltage
124WD shift indicator lamp
(4LO)ª4LOº indicator lamp comes ON. Approx. 0V
4WD shift switch is set to any posi-
tion other than ª4LOº.Battery voltage
13 Transfer shift relay (Low)
&
While actuator is operating
(4LO,4H)Battery voltage
Actuator does not operate. Approx. 0V
14 Transfer motor relayTransfer motor relay is ON. Battery voltage
Transfer motor relay is OFF. Less than 1V
15 PNP switch (N position)A/T selector lever is set to ªNº posi-
tion.Battery voltage
A/T selector lever is set to any posi-
tion other than ªNº position.Less than 1V
16 Power supply ÐIgnition key is set to ªONº position. Battery voltage
Ignition key is set to ªOFFº position. Approx. 0V
17 PNP switch (P position)
&
A/T selector lever is set to ªPº posi-
tion.Battery voltage
A/T selector lever is set to any posi-
tion other than ªPº.Less than 1V
18 4WD shift switch (4H)4WD shift switch is set to ª4Hº posi-
tion.Battery voltage
4WD shift switch is set to any posi-
tion other than ª4Hº.Less than 1V
19 4WD solenoid valve4WD shift switch is set to ªAUTOº
position.Approx. 1.5 - 3V
4WD shift switch is set to any posi-
tion other than ª2WDº.Less than 1V
20ÐÐÐÐ
214WD shift indicator lamp
(AUTO)
ªAUTOº indicator lamp comes ON. Approx. 0V
4WD shift switch is set to any posi-
tion other than ªAUTOº.Battery voltage
22 Power supply ÐIgnition key is set to ªONº position. Battery voltage
Ignition key is set to ªOFFº position. Approx. 0V
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
Transfer Control Unit Terminals and Reference Value (Cont'd)
TF-56

Terminal
No.Item Condition Judgement standard
23 4WD shift switch (4LO)
&
4WD shift switch is set to ª4LOº posi-
tion.Battery voltage
4WD shift switch is set to any posi-
tion other than ª4LOº.Less than 1V
24 4WD shift switch (AUTO)4WD shift switch is set to ªAUTOº
position.Battery voltage
4WD shift switch is set to any posi-
tion other than ªAUTOº.Less than 1V
25 Neutral-4LO switchTransfer is set to ª4LOº position. Approx. 0V
Transfer is set to any position other
than ª4LOº.Power supply
26Throttle position switch
(closed)Throttle valve is closed. Power supply
Throttle valve is in any position other
than ªclosedº.Approx. 0V
27Transfer 4H actuator
switch4WD shift switch is set to ª4Hº posi-
tion.Less than 1V
4WD shift switch is set to any posi-
tion other than ª4Hº.Battery voltage
28Throttle position sensor
(Ground)Throttle valve is closed.
Less than 1V
Throttle valve is fully open.
29TCM signal (Vehicle
speed signal)When moving at 20 km/h (12 MPH),
use the CONSULT-II pulse frequency
measuring function.*1
CAUTION:
Connect the diagnosis data link
cable to the vehicle diagnosis con-
nector.
*1: A circuit tester cannot be used to
test this item.Approximately 225 Hz
30Throttle position sensor
(Power supply for throttle
position sensor)Ignition key is set to ªONº position. Approx. 4.5 - 5.5V
Ignition key is set to ªOFFº position. Approx. 0VGI
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TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
Transfer Control Unit Terminals and Reference Value (Cont'd)
TF-57

Diagnostic ProcedureNBTF0020
1 CHECK 4WD SOLENOID VALVE
SMT775D
Refer to ª4WD Solenoid Valve, Clutch Pressure Switch and Line Pressure Switchº, ªCOMPONENT INSPECTIONº, TF-111.
OK or NG
OK©GO TO 2.
NG©Check the following. If OK, repair or replace 4WD solenoid valve.
IContinuity of transfer sub-harness
Refer to ªTRANSFER TERMINAL CORD ASSEMBLY SUB-HARNESS CONNECTORº,
ªCOMPONENT INSPECTIONº, TF-114.
2 CHECK POWER SOURCE CIRCUIT
1. Turn ignition switch to ªOFFº position.
2. Disconnect transfer control unit harness connector.
3. Check resistance between transfer terminal cord assembly sub-harness connector terminal 6 and transfer control unit
harness connector terminal 10.
Resistance: 11.2 - 12.8W
SMT776D
OK or NG
OK©GO TO 3.
NG©Check the following.
ITransfer dropping resistor
Refer to ªTransfer Dropping Resistorº, ªCOMPONENT INSPECTIONº, TF-112.
IContinuity between transfer terminal cord assembly sub-harness connector terminal 6
and transfer control unit harness connector terminal 10.
4WD SOLENOID VALVE
Diagnostic Procedure
TF-64

3 CHECK POWER SOURCE CIRCUIT
1. Turn ignition switch to ªOFFº position.
2. Check continuity between transfer terminal cord assembly sub-harness connector terminal 6 and transfer control unit
harness connector terminal 19.
Continuity should exist.
SMT777D
OK or NG
OK©GO TO 4.
NG©Repair or replace harness between transfer terminal cord assembly sub-harness connec-
tor terminal 6 and transfer control unit harness connector terminal 19.
4 PERFORM SELF-DIAGNOSIS
After driving for a while, perform self-diagnosis.
Refer to ªTrouble Diagnosis without CONSULT-IIº, TF-27 and ªTrouble Diagnosis with CONSULT-IIº, TF-30.
OK or NG
OK©INSPECTION END
NG©1. Perform transfer control unit input/output signal inspection. Refer to ªTRANSFER
CONTROL UNIT INSPECTION TABLEº, TF-55.
2. If NG, recheck transfer control unit pin terminals for damage or loose connection with
harness connector.
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4WD SOLENOID VALVE
Diagnostic Procedure (Cont'd)
TF-65

3 CHECK 4WD SHIFT SWITCH POWER SOURCE
1. Disconnect 4WD shift switch harness connector.
2. Turn ignition switch to ªONº position.
3. Check voltage between 4WD shift switch harness connector terminal 1 and body ground.
Voltage: Battery voltage
SMT852D
OK or NG
OK©GO TO 4.
NG©Check the following.
INo. 18 fuse (10A)
IContinuity between ignition switch and 4WD shift switch
2-4WD SHIFT SOLENOID VALVE AND 4WD SHIFT SWITCH
Diagnostic Procedure (Cont'd)
TF-68