2001 INFINITI QX4 ignition

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

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