02 sensor INFINITI QX4 2001 Factory Service Manual

5 CHECK INPUT SIGNAL
Without CONSULT-II
1. Start engine.
2. Check voltage between transfer control unit harness connector terminals 38 and 28.
(Measure it in AC range.)
Voltage:
0 km/h (0 MPH): 0V
30 km/h (19 MPH): More than 1V
(Voltage rises gradually in response to vehicle speed.)
SMT774D
OK or NG
OK©GO TO 6.
NG©GO TO 7.
6 PERFORM SELF-DIAGNOSIS AGAIN
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, ªTROUBLE DIAGNOSIS Ð GENERAL
DESCRIPTIONº, TF-55.
2. If NG, recheck transfer control unit pin terminals for damage or loose connection with
harness connector.
7 CHECK HARNESS CONTINUITY BETWEEN TRANSFER CONTROL UNIT AND FRONT REVOLUTION
SENSOR SUB-HARNESS CONNECTOR
OK or NG
OK©GO TO 6.
NG©Repair or replace sub-harness connector between transfer control unit and front revolu-
tion sensor.
GI
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EC
FE
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PD
AX
SU
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ST
RS
BT
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SC
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IDX
VEHICLE SPEED SENSOR (FRONT REVOLUTION SENSOR)
Diagnostic Procedure (Cont'd)
TF-63

Diagnostic ProcedureNBTF0021
1 CHECK 2-4WD SHIFT SOLENOID VALVE AND 4WD SHIFT SWITCH
Refer to ª2-4WD Shift Solenoid Valve and Transfer Fluid Temperature Sensorº, ªCOMPONENT INSPECTIONº, TF-111.
SMT778D
OK or NG
OK©GO TO 2.
NG©Check the following. If OK, repair or replace 2-4WD shift solenoid valve and 4WD
shift switch.
IContinuity of transfer sub-harness
Refer to ªTRANSFER TERMINAL CORD ASSEMBLY SUB-HARNESS CONNECTORº,
ªCOMPONENT INSPECTIONº, TF-114.
2-4WD SHIFT SOLENOID VALVE AND 4WD SHIFT SWITCH
Diagnostic Procedure
TF-66

Diagnostic ProcedureNBTF0022
1 CHECK TRANSFER MOTOR AND TRANSFER MOTOR RELAY
SMT782D
Refer to ªTransfer Motorº and ªTransfer Motor Relayº, ªCOMPONENT INSPECTIONº, TF-113.
OK or NG
OK©GO TO 3.
NG©GO TO 2.
2 CHECK CONTINUITY
Check the following.
IContinuity of transfer sub-harness
Refer to ªTRANSFER SWITCH ASSEMBLY SUB-HARNESS CONNECTORº, ªCOMPONENT INSPECTIONº, TF-114.
OK or NG
OK©Repair or replace transfer motor and transfer motor relay.
NG©Repair or replace transfer sub-harness.
3 CHECK INPUT SIGNAL
With CONSULT-II
1. Select ªMAIN SIGNALSº in Data Monitor.
2. Read out ON/OFF status of ªMOTOR RELAYº.
SMT975D
3. When the value is different from standard value although ON/OFF switching occurs, check the following items.
IPNP switch, throttle position sensor and closed throttle position switch circuits
Refer to AT-99, ªDTC P0705 Park/Neutral Position Switchº, AT-176, ªDTC P1705 Throttle Position Sensorº and AT-184,
ªClosed Throttle Position Switch (idle position)º.
OK or NG
OK©GO TO 4.
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.
TRANSFER MOTOR AND TRANSFER MOTOR RELAY
Diagnostic Procedure
TF-70

Diagnostic ProcedureNBTF0023
1 CHECK TRANSFER FLUID TEMPERATURE SENSOR
Refer to ª2-4WD Shift Solenoid Valve and Transfer Fluid Temperature Sensorº, ªCOMPONENT INSPECTIONº, TF-111.
OK or NG
OK©GO TO 3.
NG©GO TO 2.
2 CHECK CONTINUITY
Check the following.
IContinuity of transfer sub-harness
Refer to ªTRANSFER TERMINAL CORD ASSEMBLY SUB-HARNESS CONNECTORº, ªCOMPONENT INSPECTIONº,
TF-114.
OK or NG
OK©Repair or replace fluid temperature sensor.
NG©Repair or replace transfer sub-harness.
3 CHECK INPUT SIGNAL
WITH CONSULT-II©GO TO 4.
WITHOUT CONSULT-II©GO TO 5.
GI
MA
EM
LC
EC
FE
AT
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
TRANSFER FLUID TEMPERATURE SENSOR
Diagnostic Procedure
TF-73

4 CHECK INPUT SIGNAL
SMT784D
With CONSULT-II
1. Start engine.
2. Select ªECU INPUT SIGNALSº in Data Monitor.
3. Read out the value of ªFLUID TEMP SEº.
Voltage:
20ÉC (68ÉF): Approx. 1.5V
80ÉC (176ÉF): Approx. 0.5V
SMT974D
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
TRANSFER FLUID TEMPERATURE SENSOR
Diagnostic Procedure (Cont'd)
TF-74

5 CHECK INPUT SIGNAL
Without CONSULT-II
1. Turn ignition switch to ªONº position.
2. Check voltage between transfer control unit harness connector terminals 28 and 31.
Voltage:
20ÉC (68ÉF): Approx. 1.5V
80ÉC (176ÉF): Approx. 0.5V
SMT785D
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
6 PERFORM SELF-DIAGNOSIS AGAIN
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, 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
TRANSFER FLUID TEMPERATURE SENSOR
Diagnostic Procedure (Cont'd)
TF-75

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.
GI
MA
EM
LC
EC
FE
AT
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
COMPONENT INSPECTION
4WD Shift Switch
TF-111

Component
partsTerminals Remarks
4WD solenoid
valve6
Ground
terminalApprox. 20ÉC (68ÉF): Approx. 3.0 - 3.4W
Clutch pres-
sure switch7In room temperature
I2-4WD shift solenoid valve ªOFFº: No
continuity
I2-4WD shift solenoid valve and transfer
motor ªONº: Continuity exists
Line pressure
switch1In room temperature
ITurn ignition switch to ªOFFº position
and leave vehicle for more than 5 min-
utes. (OFF): No continuity
ITransfer motor ªONº: Continuity exists
SMT081D
Front Revolution SensorNBTF0038S04Measure resistance between terminals of front revolution sensor
sub-harness connector located on rear-right of transfer unit.
Terminals Resistance
16 - 17 500 - 650W
18 - 17 No continuity
18 - 16 No continuity
SMT806D
Transfer Dropping ResistorNBTF0038S07Check resistance between terminals.
Resistance: 11.2 - 12.8W
SMT083D
ATP Switch, Neutral-4LO Switch and Wait
Detection Switch
NBTF0038S06Measure resistance between terminals of transfer switch assembly
sub-harness connector located on rear-right of transfer unit.
COMPONENT INSPECTION
4WD Solenoid Valve, Clutch Pressure Switch and Line Pressure Switch (Cont'd)
TF-112

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.
GI
MA
EM
LC
EC
FE
AT
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
COMPONENT INSPECTION
ATP Switch, Neutral-4LO Switch and Wait Detection Switch (Cont'd)
TF-113

SMT087D
TRANSFER SWITCH ASSEMBLY SUB-HARNESS
CONNECTOR
NBTF0038S0902Check continuity between terminals shown in the figure.
SMT088D
TRANSFER TERMINAL CORD ASSEMBLY
SUB-HARNESS CONNECTOR
NBTF0038S0903Check continuity between terminals shown in the figure.
Terminals on solenoid valve
Terminals Components
6 4WD solenoid valve
4, 5 2-4WD shift solenoid valve
2, 3 Transfer fluid temperature sensor
7 Clutch pressure switch
1 Line pressure switch
SMT807D
Transfer Shift Relay (High & low)NBTF0038S10Check continuity between terminals 3 and 4.
Condition Continuity
12V direct current supply
between terminals 1 and 2No
No current supply Yes
COMPONENT INSPECTION
Transfer Sub-harness (Cont'd)
TF-114