elec INFINITI QX4 2001 Factory Service Manual

4 CHECK INPUT SIGNAL
SMT790D
With CONSULT-II
1. Select ªECU INPUT SIGNALSº in Data Monitor.
2. Read out the ON/OFF status of ªLINE PRES SWº.
SMT977D
OK or NG
OK©GO TO 6.
NG©Check the following.
IContinuity between transfer control unit and transfer terminal cord assembly sub-har-
ness connector
ITransfer sub-harness
ILine pressure switch
Refer to ª4WD Solenoid Valve, Clutch Pressure Switch and Line Pressure Switchº,
ªCOMPONENT INSPECTIONº, TF-111.
LINE PRESSURE SWITCH
Diagnostic Procedure (Cont'd)
TF-84

5 CHECK INPUT SIGNAL
Without CONSULT-II
1. Turn ignition switch to ªOFFº position.
2. Disconnect transfer control unit harness connector.
3. Check continuity between transfer control unit harness connector terminal 35 and body ground.
After the vehicle has been left for at least 5 minutes in a room temperature with ignition switch ªOFFº:
No continuity should exist.
With ignition switch in ªONº, 4WD shift switch in ªAUTOº or ª4Hº and A/T selector lever in ªDº:
Continuity should exist.
SMT791D
SMT849D
OK or NG
OK©GO TO 6.
NG©Check the following.
IContinuity between transfer control unit and transfer terminal cord assembly sub-har-
ness connector
ITransfer sub-harness
ILine pressure switch
Refer to ª4WD Solenoid Valve, Clutch Pressure Switch and Line Pressure Switchº,
ªCOMPONENT INSPECTIONº, TF-111.
6 PERFORM SELF-DIAGNOSIS AGAIN
1. Check hydraulic parts.
2. After driving for a while, perform self-diagnosis again. Refer to ªTrouble Diagnosis without CONSULT-IIº, TF-27.
OK or NG
OK©INSPECTION END
NG©1. Perform transfer control unit input/output signal inspection. Refer to 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
LINE PRESSURE SWITCH
Diagnostic Procedure (Cont'd)
TF-85

4 CHECK INPUT SIGNAL
With CONSULT-II
1. Start engine (idling).
2. Select ªSELF-DIAG RESULTSº in Select Diag Mode.
3. Read out self-diagnostic result.
SMT826D
SMT978D
OK or NG
OK©GO TO 7.
NG©GO TO 6.
SHIFT ACTUATOR
Diagnostic Procedure (Cont'd)
TF-90

Diagnostic ProcedureNBTF0065
1 SHIFT ACTUATOR POSITION SWITCH
Refer to ªActuator & Actuator Position Switchº, ªCOMPONENT INSPECTIONº, TF-115.
OK or NG
OK©GO TO 3.
NG©GO TO 2.
2 CHECK POSITION SWITCH
1. Recheck continuity of shift actuator position switch.
Refer to ªActuator & Actuator Position Switchº, ªCOMPONENT INSPECTIONº, TF-115.
Continuity should exist.
OK or NG
OK©GO TO 3.
NG©Repair or replace position switch.
3 CHECK INPUT SIGNAL
WITH CONSULT-II©GO TO 4.
WITHOUT CONSULT-II©GO TO 5.
4 CHECK INPUT SIGNAL
With CONSULT-II
1. Start engine (idling).
2. Select ªSELF-DIAG RESULTSº in Select Diag Mode.
3. Read out self-diagnostic result.
SMT829DA
SMT978D
OK or NG
OK©GO TO 7.
NG©GO TO 6.
SHIFT ACTUATOR POSITION SWITCH
Diagnostic Procedure
TF-92

5 CHECK INPUT SIGNAL
With CONSULT-II
1. Start engine (idling).
2. Select ªSELF-DIAG RESULTSº in Select Diag Mode.
3. Read out self-diagnostic result.
SMT835D
SMT978D
OK or NG
OK©GO TO 8.
NG©GO TO 7.
SHIFT ACTUATOR CIRCUIT
Diagnostic Procedure (Cont'd)
TF-96

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 8. Tight Corner Braking SymptomNBTF0036SYMPTOM: Tight corner braking symptom occurs. (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©Disassemble transfer unit and check the following.
IControl valve assembly
I4WD solenoid valve
I2-4WD shift solenoid valve
IClutch piston
IClutch assembly
NG©GO TO 2.
2 CHECK CLUTCH PRESSURE SWITCH 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.
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 8. Tight Corner Braking Symptom
TF-108

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.
GI
MA
EM
LC
EC
FE
AT
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
TROUBLE DIAGNOSES FOR SYMPTOMS
Symptom 9. 4WD System Does Not Operate
TF-109

SMT996C
2. Remove bolts to detach transfer cover.
IDo not reuse bolts.
SMT997C
3. Remove oil seal from transfer cover.
IDo not reuse oil seal.
SMT998C
4. Remove snap ring from main gear bearing.
IDo not reuse snap ring.
SMT999C
5. Remove sun gear by tapping it lightly.
SMT001D
6. Remove snap ring from sun gear.
IDo not reuse snap ring as it is a selective part.
7. Remove washer from sun gear.
GI
MA
EM
LC
EC
FE
AT
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DISASSEMBLY
Front Case (Cont'd)
TF-135

SMT016D
6. Install thrust needle bearing to sun gear.
7. Install sun gear to planetary carrier.
SMT017D
8. Set a support (KV40105500) to bushing replacer puller
(ST30911000) as shown in the figure, and place planetary
carrier on it.
9. Install thrust needle bearing to planetary carrier with its roller
facing front case.
10. Measure ªCº from the end of sun gear to the roller surface of
thrust needle bearing.
SMT018D
11. Measure ªDº from the end of sun gear to the main gear bear-
ing contact surface.
12. Calculate end play ªEº using ªCº and ªDº obtained in steps 10
and 11. Select bearing race so that the end play becomes the
standard value.
Calculation formula:
End play ªEº = ªCº þ ªDº
Standard end play:
0.1 - 0.25 mm (0.0039 - 0.0098 in)
Bearing race:
Refer to SDS, TF-159.
SMT019D
13. Set planetary carrier to press in the status described in step 8.
Then install the selected bearing race to planetary carrier.
SMT020D
14. Install front case to planetary carrier. Set a support ring
(KV40105310) and an adapter B (KV40105230) to main gear
bearing inner race, then press it.
ASSEMBLY
Front Case (Cont'd)
TF-142