ignition INFINITI QX4 2001 Factory Service Manual

Terminal
No.Item Condition Judgement standard
23 4WD shift switch (4LO)
&
4WD shift switch is set to ª4LOº posi-
tion.Battery voltage
4WD shift switch is set to any posi-
tion other than ª4LOº.Less than 1V
24 4WD shift switch (AUTO)4WD shift switch is set to ªAUTOº
position.Battery voltage
4WD shift switch is set to any posi-
tion other than ªAUTOº.Less than 1V
25 Neutral-4LO switchTransfer is set to ª4LOº position. Approx. 0V
Transfer is set to any position other
than ª4LOº.Power supply
26Throttle position switch
(closed)Throttle valve is closed. Power supply
Throttle valve is in any position other
than ªclosedº.Approx. 0V
27Transfer 4H actuator
switch4WD shift switch is set to ª4Hº posi-
tion.Less than 1V
4WD shift switch is set to any posi-
tion other than ª4Hº.Battery voltage
28Throttle position sensor
(Ground)Throttle valve is closed.
Less than 1V
Throttle valve is fully open.
29TCM signal (Vehicle
speed signal)When moving at 20 km/h (12 MPH),
use the CONSULT-II pulse frequency
measuring function.*1
CAUTION:
Connect the diagnosis data link
cable to the vehicle diagnosis con-
nector.
*1: A circuit tester cannot be used to
test this item.Approximately 225 Hz
30Throttle position sensor
(Power supply for throttle
position sensor)Ignition key is set to ªONº position. Approx. 4.5 - 5.5V
Ignition key is set to ªOFFº position. Approx. 0VGI
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TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
Transfer Control Unit Terminals and Reference Value (Cont'd)
TF-57

Diagnostic ProcedureNBTF0020
1 CHECK 4WD SOLENOID VALVE
SMT775D
Refer to ª4WD Solenoid Valve, Clutch Pressure Switch and Line Pressure Switchº, ªCOMPONENT INSPECTIONº, TF-111.
OK or NG
OK©GO TO 2.
NG©Check the following. If OK, repair or replace 4WD solenoid valve.
IContinuity of transfer sub-harness
Refer to ªTRANSFER TERMINAL CORD ASSEMBLY SUB-HARNESS CONNECTORº,
ªCOMPONENT INSPECTIONº, TF-114.
2 CHECK POWER SOURCE CIRCUIT
1. Turn ignition switch to ªOFFº position.
2. Disconnect transfer control unit harness connector.
3. Check resistance between transfer terminal cord assembly sub-harness connector terminal 6 and transfer control unit
harness connector terminal 10.
Resistance: 11.2 - 12.8W
SMT776D
OK or NG
OK©GO TO 3.
NG©Check the following.
ITransfer dropping resistor
Refer to ªTransfer Dropping Resistorº, ªCOMPONENT INSPECTIONº, TF-112.
IContinuity between transfer terminal cord assembly sub-harness connector terminal 6
and transfer control unit harness connector terminal 10.
4WD SOLENOID VALVE
Diagnostic Procedure
TF-64

3 CHECK POWER SOURCE CIRCUIT
1. Turn ignition switch to ªOFFº position.
2. Check continuity between transfer terminal cord assembly sub-harness connector terminal 6 and transfer control unit
harness connector terminal 19.
Continuity should exist.
SMT777D
OK or NG
OK©GO TO 4.
NG©Repair or replace harness between transfer terminal cord assembly sub-harness connec-
tor terminal 6 and transfer control unit harness connector terminal 19.
4 PERFORM SELF-DIAGNOSIS
After driving for a while, perform self-diagnosis.
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, TF-55.
2. If NG, recheck transfer control unit pin terminals for damage or loose connection with
harness connector.
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4WD SOLENOID VALVE
Diagnostic Procedure (Cont'd)
TF-65

3 CHECK 4WD SHIFT SWITCH POWER SOURCE
1. Disconnect 4WD shift switch harness connector.
2. Turn ignition switch to ªONº position.
3. Check voltage between 4WD shift switch harness connector terminal 1 and body ground.
Voltage: Battery voltage
SMT852D
OK or NG
OK©GO TO 4.
NG©Check the following.
INo. 18 fuse (10A)
IContinuity between ignition switch and 4WD shift switch
2-4WD SHIFT SOLENOID VALVE AND 4WD SHIFT SWITCH
Diagnostic Procedure (Cont'd)
TF-68

4 CHECK HARNESS CONTINUITY
1. Turn ignition switch to ªOFFº position.
2. Check continuity between the following terminals:
ITransfer control unit 9 and 4WD shift switch 2 (2WD)
ITransfer control unit 18 and 4WD shift switch 5 (4H)
ITransfer control unit 24 and 4WD shift switch 3 (AUTO)
ITransfer control unit 23 and 4WD shift switch 6 (4LO)
ITransfer control unit 1 and Transfer terminal cord assembly sub-harness connector 4
I4WD shift switch 4 and Transfer terminal cord assembly sub-harness connector 5
Continuity should exist.
SMT853D
OK or NG
OK©GO TO 5.
NG©Repair harness or connector.
5 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.
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2-4WD SHIFT SOLENOID VALVE AND 4WD SHIFT SWITCH
Diagnostic Procedure (Cont'd)
TF-69

4 CHECK TRANSFER MOTOR RELAY POWER SOURCE
1. Disconnect transfer motor relay harness connector.
2. Turn ignition switch to ªONº position.
3. Check voltage between transfer motor relay harness connector terminals 1, 3 and body ground.
Voltage: Battery voltage
SMT854DA
OK or NG
OK©GO TO 5.
NG©Check the following.
INo. 55 fuse (20A)
INo. 18 fuse (10A)
IHarness continuity between fuse and transfer motor relay
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TRANSFER MOTOR AND TRANSFER MOTOR RELAY
Diagnostic Procedure (Cont'd)
TF-71

5 CHECK HARNESS CONTINUITY
1. Turn ignition switch to ªOFFº position.
2. Check continuity between the following terminals.
ITransfer control unit 41 and Transfer motor 14
ITransfer control unit 41 and Transfer motor relay 2
ITransfer control unit 14 and Transfer motor relay 4
ITransfer motor 15 and body ground
Continuity should exist.
SMT855DA
OK or NG
OK©GO TO 6.
NG©Repair or replace harness or connector.
6 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.
TRANSFER MOTOR AND TRANSFER MOTOR RELAY
Diagnostic Procedure (Cont'd)
TF-72

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.
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TRANSFER FLUID TEMPERATURE SENSOR
Diagnostic Procedure (Cont'd)
TF-75

5 CHECK INPUT SIGNAL
Without CONSULT-II
1. Turn ignition switch to ªOFFº position.
2. Operate 4WD shift switch and check continuity between the following terminals.
Continuity:
Terminal 40 (ATP switch) and body ground
ª4Hº position: No continuity should exist.
Between ª4Hº and ª4LOº: Continuity should exist.
ª4LOº position: No continuity should exist.
Terminal 25 (Neutral-4LO switch) and body ground
ª4Hº position: No continuity should exist.
ª4LOº position: Continuity should exist.
Terminal 43 (Wait detection switch) and body ground
ª4Hº position: No continuity should exist. (*1)
ª4LOº position: Continuity should exist.
*1: After setting from ª4LOº to ª4Hº, continuity exists while ªWaitº function is operating in ª4Hº position.
(No continuity exists when ªWaitº function is canceled.)
SMT787D
SMT849D
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
ATP SWITCH, WAIT DETECTION SWITCH AND NEUTRAL-4LO SWITCH
Diagnostic Procedure (Cont'd)
TF-78

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.
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CLUTCH PRESSURE SWITCH
Diagnostic Procedure (Cont'd)
TF-81