ignition INFINITI QX4 2001 Factory Service Manual

6 CHECK INPUT SIGNAL
Without CONSULT-II
1. Turn ignition switch to ªONº position and set 4WD shift switch to ª4Hº position.
2. Check voltage between transfer control unit harness connector terminal 34 and body ground.
When 4WD shift switch is in ª2WDº:
Battery voltage should exist.
When 4WD shift switch is in ªAUTOº or ª4Hº and A/T selector lever is in ªDº:
ªWaitº operating: Battery voltage should exist.
ªWaitº not operating: Approx. 0 volts should exist.
SMT789D
SMT849D
OK or NG
OK©GO TO 7.
NG©Check the following.
IContinuity between transfer control unit and transfer terminal cord assembly sub-har-
ness connector
ITransfer sub-harness
IClutch pressure switch
Refer to ª4WD Solenoid Valve, Clutch Pressure Switch and Line Pressure Switchº,
ªCOMPONENT INSPECTIONº, TF-111.
7 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 ªTRANSFER
CONTROL UNIT INSPECTION TABLEº, TF-55.
2. If NG, recheck transfer control unit pin terminals for damage or loose connection with
harness connector.
CLUTCH PRESSURE SWITCH
Diagnostic Procedure (Cont'd)
TF-82

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.
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LINE PRESSURE SWITCH
Diagnostic Procedure (Cont'd)
TF-85

Diagnostic ProcedureNBTF0027
1 CHECK INPUT SIGNAL
WITHOUT CONSULT-II©GO TO 2.
2 CHECK INPUT SIGNAL
Without CONSULT-II
1. Turn ignition switch to ªOFFº position.
2. Disconnect ABS control unit harness connector.
3. Disconnect ABS control unit and transfer control unit harness connectors.
4. Check continuity between transfer control unit harness connector terminal 32 and ABS control unit harness connector
terminal 13.
Continuity should exist.
5. Check continuity between transfer control unit harness connector terminal 32, ABS control unit harness connector ter-
minal 13 and body ground.
No continuity should exist.
SMT793DA
OK or NG
OK©GO TO 3.
NG©Repair or replace harness or connector between ABS control unit and transfer control
unit.
3 CHECK COMMUNICATION LINE
Check communication line between ABS control unit and transfer control unit.
(Refer to BR-77, ª8. Vehicle vibrates excessively when ABS is operatingº.)
OK or NG
OK©GO TO 4.
NG©Check, repair or replace faulty parts.
ABS OPERATION SIGNAL
Diagnostic Procedure
TF-86

Diagnostic ProcedureNBTF0028
1 CHECK TRANSFER CONTROL UNIT POWER SOURCE
1. Turn ignition switch to ªOFFº position and perform self-diagnosis again.
Refer to ªTrouble Diagnosis without CONSULT-IIº, TF-27 and ªTrouble Diagnosis with CONSULT-IIº, TF-30.
2. Turn ignition switch to ªOFFº position.
3. Disconnect transfer control unit harness connector.
4. Check voltage between transfer control unit harness connector terminal 47 and body ground.
Voltage: Battery voltage
SMT794D
OK or NG
OK©GO TO 2.
NG©Check the following.
INo. 24 fuse (7.5A)
IHarness continuity between fuse and transfer control unit
2 PERFORM SELF-DIAGNOSIS AGAIN
After driving for a while, perform 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©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.
DATA ERASE/DISPLAY
Diagnostic Procedure
TF-88

Diagnostic ProcedureNBTF0064
1 SHIFT ACTUATOR
Refer to ªActuator & Actuator Position Switchº, ªCOMPONENT INSPECTIONº, TF-115.
OK or NG
OK©GO TO 3.
NG©GO TO 2.
2 CHECK POWER SOURCE
SMT825DA
1. Disconnect transfer control device terminal.
2. Turn ignition switch to ªONº. (Do not start engine.)
3. Check voltage between transfer control device harness connector 3 (or 4) and body ground while 4WD shift switch is
set from 4H to 4LO (or from 4LO to 4H).
Voltage: Battery voltage
OK or NG
OK©Repair or replace actuator.
NG©1. Recheck the following.
IContinuity between ignition switch and transfer HI & LOW relays
IIgnition switch and No. 3 fuse (20A)
IContinuity between transfer shift HI & LOW relays and transfer control device
2. If NG, repair or replace damaged part.
3 CHECK INPUT SIGNAL
WITH CONSULT-II©GO TO 4.
WITHOUT CONSULT-II©GO TO 5.
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MA
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LC
EC
FE
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PD
AX
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BR
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RS
BT
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SC
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IDX
SHIFT ACTUATOR
Diagnostic Procedure
TF-89

Diagnostic ProcedureNBTF0066
1 SHIFT ACTUATOR CIRCUIT
Refer to ªTransfer Shift Relay (High & Low)º, ªCOMPONENT INSPECTIONº and ªActuator & Actuator Position Switchº,
ªCOMPONENT INSPECTIONº, TF-114, 115.
OK or NG
OK©GO TO 2.
NG©Repair or replace transfer shift relay and actuator and actuator position switch.
2 CHECK POWER SOURCE OF TRANSFER SHIFT (HI & LOW) RELAY
SMT825DA
1. Disconnect transfer control device terminal.
2. Turn ignition switch to ªONº (Do not start engine).
3. Check voltage between transfer shift HI and LOW relay terminal 5 and body ground.
Voltage: Battery voltage
SMT831D
OK or NG
OK©GO TO 3.
NG©Check the following.
IContinuity between ignition switch and transfer shift HI & LOW relays
ICheck ground circuit between transfer shift HI & LOW relays and body ground.
IIgnition switch and No. 3 fuse (20A)
SHIFT ACTUATOR CIRCUIT
Diagnostic Procedure
TF-94

3 CHECK POWER SOURCE OF TRANSFER CONTROL DEVICE
1. Disconnect transfer control device terminal.
2. Turn ignition switch to ªONº. (Do not start engine.)
3. Turn 4WD shift switch from ª4Hº to ª4LOº (or from ª4LOº to ª4Hº).
4. Check voltage between transfer control device terminal 3 (or 4) and body ground.
Voltage: Battery voltage
SMT832D
OK or NG
OK©GO TO 4.
NG©Check the following.
IHarness and connector from transfer shift HI and LOW relays to transfer control
device harness terminal
IGround circuit between transfer control device and body ground.
4 CHECK INPUT SIGNAL
WITH CONSULT-II©GO TO 5.
WITHOUT CONSULT-II©GO TO 6.
GI
MA
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LC
EC
FE
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PD
AX
SU
BR
ST
RS
BT
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SC
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IDX
SHIFT ACTUATOR CIRCUIT
Diagnostic Procedure (Cont'd)
TF-95

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.
GI
MA
EM
LC
EC
FE
AT
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
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