IDX INFINITI QX4 2001 Factory Service Manual

Symptom 9. 4WD System Does Not Operate=NBTF0037SYMPTOM: The vehicle cannot be put into 4WD mode.
(Hydraulic system failure)
1 CHECK INPUT SIGNAL
With CONSULT-II
1. Select ªECU INPUT SIGNALSº in Data Monitor.
2. Read out the ON/OFF status of ªCLUTCH PRES SWº.
SMT977D
Without CONSULT-II
Check voltage between transfer control unit harness connector terminal 34 and body ground.
Refer to ªTRANSFER CONTROL UNIT INSPECTION TABLEº, ªTROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONº,
TF-55.
OK or NG
OK©1. Check transfer fluid level.
2. Disassemble transfer unit and check the following.
ITransfer motor
IMain oil pump assembly
ISub-oil pump assembly
IOil strainer
IControl valve assembly
I2-4WD shift solenoid valve
IOil filter element
ILip seal
IStrainer O-ring
IMain oil pump drive gear
ISeal ring
ID-ring
IClutch piston
IClutch assembly
NG©GO TO 2.
2 CHECK CLUTCH PRESSURE CIRCUIT
Check clutch pressure switch circuit.
Refer to ªDiagnostic Procedureº, ªCLUTCH PRESSURE SWITCHº, TF-80.
OK or NG
OK©GO TO 3.
NG©Check, repair or replace faulty parts.
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TROUBLE DIAGNOSES FOR SYMPTOMS
Symptom 9. 4WD System Does Not Operate
TF-109

NBTF0038
SMT858D
4WD Shift SwitchNBTF0038S01Check continuity between each terminal.
Terminals Switch position Continuity
1-22WD Yes
Except 2WD No
1-3,1-4AUTO Yes
Except AUTO No
1-4,1-54H Yes
Except 4H No
1-4,1-64LO Yes
Except 4LO No
SMT079D
2-4WD Shift Solenoid Valve and Transfer Fluid
Temperature Sensor
NBTF0038S02Measure resistance between terminals of transfer terminal cord
assembly sub-harness connector located on rear-right of transfer
unit.
Component parts Terminals Resistance
2-4WD shift solenoid valve 4 - 5Approx. 20ÉC (68ÉF):
Approx. 22.8 - 25.2W
Transfer fluid temperature
sensor2-3Approx. 20ÉC (68ÉF): Approx. 2.5 kW
Approx. 80ÉC (176ÉF): Approx. 0.3
kW
SMT080D
4WD Solenoid Valve, Clutch Pressure Switch
and Line Pressure Switch
NBTF0038S03Measure resistance between terminals of transfer terminal cord
assembly sub-harness connector located on rear-right of transfer
unit.
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COMPONENT INSPECTION
4WD Shift Switch
TF-111

Switch Terminals4WD shift switch position
4H (N) 4LO
ATP switch 8 - 9No conti-
nuityContinuityNo conti-
nuity
Neutral-4LO
switch12 - 13 No continuity Continuity
Wait detection
switch10-11No continuity Continuity
(Note)
+---------------------------
NOTE:
When shifting from ª4LOº to ª4Hº, continuity exists while ªWaitº function is operat-
ing. (No continuity exists when ªWaitº function is canceled.)
SMT082D
Transfer MotorNBTF0038S05Apply battery voltage directly to transfer motor assembly sub-har-
ness connector located on rear-right of transfer unit. (Positive: Ter-
minal 14, Negative: Terminal 15)
Transfer motor should operate.
SMT085D
Transfer Motor RelayNBTF0038S081. Apply battery voltage directly to terminals 3 and 4.
2. Check continuity between terminals 1 and 2.
Condition Continuity (1 - 2)
Battery voltage is applied Yes
No voltage is applied No
SMT086DB
Transfer Sub-harnessNBTF0038S09FRONT REVOLUTION SENSOR SUB-HARNESS
CONNECTOR
NBTF0038S0901Check continuity between terminals shown in the figure.
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COMPONENT INSPECTION
ATP Switch, Neutral-4LO Switch and Wait Detection Switch (Cont'd)
TF-113

SMT812D
Actuator & Actuator Position SwitchNBTF0038S11ACTUATORNBTF0038S1101Operation & resistance check
IApply battery voltage directly to actuator assembly.
Operating check Battery positive terminal Battery negative terminal
143
234
Check Approx. 0.2W(When the motor is not operated.)
SMT838D
ACTUATOR POSITION SWITCHNBTF0038S1102Continuity check
Continuity checkBattery positive
terminalBattery negative
terminalContinuity
14 3 1-5
23 4 2-5
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COMPONENT INSPECTION
Actuator & Actuator Position Switch
TF-115

SMT808D
SHIFT SHAFT OIL SEALNBTF0068S021. Remove front propeller shaft. Refer to PD-6, ªRemoval and
Installationº.
2. Remove companion flange. Refer to ªFRONT CASE OIL
SEALº, TF-116.
3. Remove actuator lever from transfer outer shift lever. Then
remove outer shift lever.
SMT491A
4. Remove shift shaft oil seal.
IBe careful not to damage cross shaft.
SMT805C
5. Install shift shaft oil seal.
IBefore installing, apply multi-purpose grease to seal lip.
6. Install transfer control linkage.
7. Install companion flange. Refer to ªFRONT CASE OIL SEALº,
TF-116.
8. Install front propeller shaft.
SMT892C
REAR OIL SEALNBTF0068S031. Remove rear propeller shaft. Refer to PD-6, ªRemoval and
Installationº.
2. Remove rear oil seal.
3. Install rear oil seal.
IBefore installing, apply multi-purpose grease to seal lip.
4. Install rear propeller shaft.
SMT874C
Transfer Motor
REMOVALNBTF00691. Disconnect transfer motor harness connector.
2. Remove breather pipe from transfer motor.
3. Remove bolts to detach transfer motor.
IAfter removing transfer motor, be sure to replace O-ring
with new one.
INSTALLATIONNBTF00701. Apply petroleum jelly or ATF to O-ring.
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ON-VEHICLE SERVICE
Replacing Oil Seal (Cont'd)
TF-117

SMT897C
RemovalNBTF00731. Remove exhaust front and rear tubes. Refer to FE-8,
ªEXHAUST SYSTEMº.
2. Remove front and rear propeller shaft. Refer to PD-6,
ªRemoval and Installationº.
3. Insert plug into rear oil seal after removing propeller shaft.
IBe careful not to damage spline, sleeve yoke and rear oil
seal, when removing propeller shaft.
4. Disconnect neutral-4LO switch, front revolution sensor, ATP
switch, transfer motor and 4WD shift switch harness connec-
tors.
SMT808D
5. Remove center console and A/T control device.
6. Remove floor panel for transfer.
7. Remove upper side fixing bolt for A/T and TF.
8. Remove actuator lever from transfer outer shift lever and
remove sub-oil pump from transfer.
9. Remove remaining fixing bolt for AT and TF.
SMT899C
SMT871C
10. Remove transfer from transmission.
WARNING:
Support transfer while removing it.
SMT872C
InstallationNBTF0074ITighten bolts securing transfer.
Bolt length:
45 mm (1.77 in)
Tightening torque:
: 31 - 42 N´m (3.2 - 4.3 kg-m, 23 - 31 ft-lb)
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REMOVAL AND INSTALLATION
Removal
TF-119

Transfer ComponentsNBTF0076
SMT810D
1. Oil seal
2. Transfer cover
3. Snap ring
4. Washer
5. Snap ring
6. Main gear bearing
7. Front case
8. Check plug
9. Check spring
10. Check ball
11. Internal gear
12. Snap ring
13. Bearing race
14. Thrust needle bearing
15. Planetary carrier
16. Thrust needle bearing
17. Sun gear18. L-H sleeve
19. 2-4 sleeve
20. Radial needle bearing
21. Front revolution sensor
22. Roll pin
23. L-H fork
24. 2-4 fork
25. Shift fork spring
26. Fork guide
27. Roll pin
28. Shift rod
29. Self-lock nut
30. Companion flange
31. Oil seal
32. Drain plug
33. Wait detection switch
34. Needle bearing35. Mainshaft
36. Drive chain
37. Clutch drum
38. Clutch hub
39. Snap ring
40. Driven plate
41. Drive plate
42. Retaining plate
43. Return spring assembly
44. Press flange
45. Washer
46. Thrust needle bearing
47. Snap ring
48. Seal ring
49. Front bearing
50. Front drive shaft
51. Rear bearing
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OVERHAUL
Transfer Components
TF-121

SMT877C
Rear Case
DISASSEMBLYNBTF00771. Remove neutral-4LO switch and ATP switch.
2. Remove bolts.
SMT878C
3. Remove rear case from center case by tapping it lightly with a
plastic hammer.
SMT883C
Center Case
DISASSEMBLYNBTF00781. Remove oil pump shaft from main oil pump.
SMT884C
2. Remove stem bleeder from bleeder hole.
SMT844DB
3. Remove lock nut from companion flange.
IDo not reuse lock nut.
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DISASSEMBLY
Rear Case
TF-123

SMT900C
Front Drive Shaft and Drive ChainNBTF0078S011. Remove oil gutter from center case.
2. With front drive shaft held by one hand as shown in the figure,
tap center case with a plastic hammer to remove it with drive
chain.
IDo not tap drive chain with a plastic hammer.
SMT901CB
3. Set a puller (ST30021000) and an adapter (ST33052000).
Remove front drive shaft front bearing.
SMT902CB
4. Set the puller (ST30021000) and the adapter (ST33052000).
Remove front drive shaft rear bearing.
SMT903CA
Mainshaft and Clutch DrumNBTF0078S021. Remove mounting bolts to detach baffle plate.
SMT904C
2. Set center case to press stand. Remove mainshaft from cen-
ter case.
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DISASSEMBLY
Center Case (Cont'd)
TF-125

SMT910C
8. Remove press flange from mainshaft.
SMT911C
9. Remove return spring assembly from clutch hub.
SMT912C
10. Remove each plate from clutch drum.
SMT913C
11. Remove snap ring from mainshaft.
IDo not reuse snap ring.
SMT914C
12. Tap mainshaft with a plastic hammer to remove it from clutch
drum and clutch hub.
13. Remove needle bearing from mainshaft.
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DISASSEMBLY
Center Case (Cont'd)
TF-127