elec INFINITI QX4 2001 Factory Service Manual

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
31Transfer fluid tempera-
ture sensor
&
At 20ÉC (68ÉF) Approx. 1.5V
At 80ÉC (176ÉF) Approx. 0.5V
32 ABS signalWhen moving, use the CONSULT-II
pulse frequency measuirng func-
tion.*2
CAUTION:
Connect the diagnosis data link
cable to the vehicle diagnosis con-
nector.
*2: A circuit tester cannot be used to
test this item.Refer to the illustration
(SMT973D) at the end of
this section.
33Transfer shift relay
(High)While actuator is operating from ª4Hº
to ª4LOºBattery voltage
Actuator does not operate. Approx. 0V
34 Clutch pressure switch4WD shift switch is set to ªAUTOº or
ª4Hº, then A/T selector lever is set to
ªDº position. (wait detection system:
OFF)Battery voltage
4WD shift switch is set to ª2WDº,
ªAUTOº or ª4Hº, then A/T selector
lever is set to ªDº position. (wait
detection system: ON)Approx. 0V
35 Line pressure switch4WD shift switch is set to ª2WDº,
ªAUTOº or ª4Hº, then A/T selector
lever is set to ªDº position.Battery voltage
Ð Approx. 0V
36 CONSULT-II (RX) Ð Ð Ð
37 Tachometer
ÐRefer to EC-127, ªECM
Inspection Tableº.
38 Front revolution sensor
4WD shift switch is set to ª4Hº posi-
tion. A/T selector lever is set to ªDº
position.Approx. 1V [30 km/h (19
MPH)]
Voltage rises in
response to vehicle
speed.
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
Transfer Control Unit Terminals and Reference Value (Cont'd)
TF-58

Terminal
No.Item Condition Judgement standard
39ECM (Throttle position
sensor)
&
Throttle valve is fully open. Approx. 0.5V
Throttle valve is closed. Approx. 4.2V
40 ATP switchA/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
41Transfer motor relay
monitorTransfer motor relay is ON. Battery voltage
Transfer motor relay is OFF. Less than 1V
42Transfer shift relay
(LOW)While actuator is operating from
ª4LOº to ª4Hº positionBattery voltage
Actuator does not operate. Approx. 0V
43 Wait detection switch4WD shift switch is set to any posi-
tion other than ª4LOº.Battery voltage
4WD shift switch is set to ª4LOº posi-
tion.*3Less than 1V
44Transfer 4LO actuator
switch4WD shift switch is set to any posi-
tion other than ª4LOº. (Actuator: High
position)Battery voltage
4WD shift switch is set to ª4LOº posi-
tion. (Actuator: Low position)Less than 1V
45 Ground Ð Ð Ð
46ÐÐÐÐ
47Power supply (memory
back up)
&Ð Battery voltage
48 CONSULT-II (TX) Ð Ð Ð
*3: While wait detection system is operating, terminal 43 exists battery voltage.
GI
MA
EM
LC
EC
FE
AT
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
Transfer Control Unit Terminals and Reference Value (Cont'd)
TF-59

4 CHECK INPUT SIGNAL
With CONSULT-II
1. Start engine.
2. Select ªECU INPUT SIGNALSº in Data Monitor.
3. Read out the value of ªVEHICLE SPEED SENSOR (FRONT)º while driving.
SMT773D
SMT974D
4. Check if the value changes according to accelerating and decelerating the vehicle.
OK or NG
OK©GO TO 6.
NG©GO TO 7.
VEHICLE SPEED SENSOR (FRONT REVOLUTION SENSOR)
Diagnostic Procedure (Cont'd)
TF-62

2 CHECK INPUT SIGNAL
With CONSULT-II
1. Select ªECU INPUT SIGNALSº in Data Monitor.
2. Read out ON/OFF status of ª2WD SWº and ªLOCK SWITCHº.
SMT974D
OK or NG
OK©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.
NG©GO TO 3.
GI
MA
EM
LC
EC
FE
AT
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
2-4WD SHIFT SOLENOID VALVE AND 4WD SHIFT SWITCH
Diagnostic Procedure (Cont'd)
TF-67

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

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

4 CHECK INPUT SIGNAL
With CONSULT-II
1. Select ªECU INPUT SIGNALSº in Data Monitor.
2. Read out the ON/OFF status of ªATP SWº, ªNEUTRAL SWº and ªWAIT DETCT SWº.
SMT976D
OK or NG
OK©GO TO 6.
NG©Check the following.
IHarness continuity between transfer switch assembly sub-harness connector and
transfer control unit
IContinuity between transfer switch assembly sub-harness connector and body ground
GI
MA
EM
LC
EC
FE
AT
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
ATP SWITCH, WAIT DETECTION SWITCH AND NEUTRAL-4LO SWITCH
Diagnostic Procedure (Cont'd)
TF-77

5 CHECK INPUT SIGNAL
With CONSULT-II
1. Turn ignition switch to ªONº position.
2. Select ªECU INPUT SIGNALSº in Data Monitor.
3. Read out ON/OFF status of ªCL PRES SWº.
SMT788D
SMT977D
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.
GI
MA
EM
LC
EC
FE
AT
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
CLUTCH PRESSURE SWITCH
Diagnostic Procedure (Cont'd)
TF-81

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