Air INFINITI QX56 2004 Factory Service Manual

SHIFT ACTUATOR
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Revision: August 20072004 QX56
SHIFT ACTUATORPFP:00000
Diagnostic ProcedureEDS0018B
1. SHIFT ACTUATOR
Refer to TF-97, "
ACTUATOR AND ACTUATOR POSITION SWITCH" .
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2. CHECK POWER SOURCE
1. Disconnect transfer control device harness connector F58.
2. Turn ignition switch to ON. (Do not start engine)
3. Check voltage between transfer control device harness connec-
tor F58 terminal 21 (R/L) [or 24 (P/G)] and ground while 4WD
shift switch is set from 4H to 4LO (or from 4LO to 4H).
OK or NG
OK >> Repair or replace actuator.
NG >> 1. Recheck the following.
–Continuity between ignition switch and transfer shift
HIGH & LOW relays
–Ignition switch and No. 57 fuse (20A)
–Continuity between transfer shift HIGH & LOW relays and transfer control device
2. If NG, repair or replace damaged part.
3. CHECK INPUT SIGNAL
Do you have CONSULT-II?
Ye s o r N o
Yes >> GO TO 4.
No >> GO TO 5.Voltage : Battery voltage
WDIA0089E

SHIFT ACTUATOR
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Revision: August 20072004 QX56
6. CHECK HARNESS CONTINUITY BETWEEN TRANSFER CONTROL UNIT AND TRANSFER CON-
TROL DEVICE
OK or NG
OK >> GO TO 7.
NG >> Repair and replace harness connector between transfer control unit and transfer control device.
7. PERFORM SELF-DIAGNOSIS AGAIN
After driving for a while, perform self-diagnosis again.
Refer to TF-27, "
Trouble Diagnosis without CONSULT-II" .
OK or NG
OK >> Inspection End.
NG >> 1. Perform transfer control unit/output signal inspection. Refer to TF-55, "
TRANSFER CONTROL
UNIT INSPECTION TABLE" .
2. If NG, recheck transfer control unit pin terminals for damage or loose connection with harness
connector.

TF-80
SHIFT ACTUATOR POSITION SWITCH
Revision: August 20072004 QX56
SHIFT ACTUATOR POSITION SWITCHPFP:00000
Diagnostic ProcedureEDS0018C
1. SHIFT ACTUATOR POSITION SWITCH
Refer to TF-97, "
ACTUATOR AND ACTUATOR POSITION SWITCH" .
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2. CHECK POSITION SWITCH
Recheck continuity of shift actuator position switch.
Refer to TF-97, "
ACTUATOR AND ACTUATOR POSITION SWITCH" .
Continuity should exist.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace position switch.
3. CHECK INPUT SIGNAL
Do you have CONSULT-II?
Ye s o r N o
Yes >> GO TO 4.
No >> GO TO 5.
4. CHECK INPUT SIGNAL
With CONSULT-II
1. Start engine (idling).
2. Select “SELF-DIAG RESULTS” in Select Diag Mode.
3. Read out self-diagnostic result.
OK or NG
OK >> GO TO 6.
NG >> Check the following.

Continuity between transfer control unit and transfer
control device.

Check ground circuit between transfer control device
and ground.
WDIA0078E
SMT978D

TF-82
SHIFT ACTUATOR CIRCUIT
Revision: August 20072004 QX56
SHIFT ACTUATOR CIRCUITPFP:00000
Diagnostic ProcedureEDS0018D
1. SHIFT ACTUATOR CIRCUIT
Refer to TF-97, "
TRANSFER SHIFT RELAY (HIGH & LOW)" and TF-97, "ACTUATOR AND ACTUATOR
POSITION SWITCH" .
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
1. Disconnect transfer control device harness connector F58.
2. Turn ignition switch to ON (Do not start engine).
3. Check voltage between transfer shift HIGH relay E46 and LOW relay E47 terminal 5 (R) and ground.
OK or NG
OK >> GO TO 3.
NG >> Check the following.

Continuity between ignition switch and transfer shift HIGH & LOW relays

Ignition switch and No. 57 fuse (20A)
WDIA0089E
Voltage : Battery voltage
LDIA0080E

TF-84
SHIFT ACTUATOR CIRCUIT
Revision: August 20072004 QX56
6. CHECK INPUT SIGNAL
Without CONSULT-II
1. Start engine (idling).
2. Check voltage between transfer control unit harness connector
E142 terminal 4 (Y/L) [or 13 (G/B)] and ground while 4WD shift
switch is set from 4H to 4LO (or from 4LO to 4H).
3. Result
OK or NG
OK >> GO TO 8.
NG >> GO TO 7.
7. CHECK HARNESS CONTINUITY BETWEEN TRANSFER CONTROL UNIT AND TRANSFER SHIFT
HIGH AND LOW RELAYS
OK or NG
OK >> GO TO 8.
NG >> Repair and replace harness connector between transfer control unit and transfer shift HIGH or
LOW relay.
8. PERFORM SELF-DIAGNOSIS AGAIN
After driving for a while, perform self-diagnosis again.
Refer to TF-27, "
Trouble Diagnosis without CONSULT-II" .
OK or NG
OK >> Inspection End.
NG >> 1. Perform transfer control unit/output signal inspection. Refer to TF-55, "
TRANSFER CONTROL
UNIT INSPECTION TABLE" .
2. If NG, recheck transfer control unit pin terminals for damage or loose connection with harness
connector.
LDIA0083E
Terminal ConditionVo l ta g e
(Approx.)
4While actuator is
operating for 4H to
4LOBattery voltage
Actuator does not
operate0V
13While actuator is
operating for 4LO to
4HBattery voltage
Actuator does not
operate0V

TROUBLE DIAGNOSES FOR SYMPTOMS
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Symptom 2. 4WD Warning Lamp Does Not Turn ON (Although the ignition
switch is turned ON, the 4WD warning lamp does not turn ON)
EDS0018F
1. CHECK TRANSFER CONTROL UNIT POWER SOURCE
1. Turn ignition switch to OFF position and disconnect transfer control unit harness connector E142.
2. Turn ignition switch to ON position (do not start engine).
3. Check voltage between transfer control unit harness connector
E142 terminals 16 (Y/R), 22 (Y/R) and ground.
OK or NG
OK >> GO TO 2.
NG >> Check the following.

Continuity between ignition switch and transfer con-
trol unit

Ignition switch and No. 49 fuse (10A)
2. CHECK TRANSFER CONTROL UNIT GROUND CIRCUIT
1. Turn ignition switch to OFF position.
2. Disconnect transfer control unit harness connectors E142 and
E143.
3. Measure resistance between transfer control unit harness con-
nectors E142 and E143 terminals 3 (B), 6 (B), 45 (B) and
ground.
OK or NG
OK >> GO TO 3.
NG >> Check continuity between transfer control unit and
ground.
3. CHECK 4WD WARNING LAMP CIRCUIT AND COMBINATION METER
Check the following.

Combination meter. Refer to DI-17, "How to Proceed With Trouble Diagnosis" .

Continuity between ignition switch and combination meter

Continuity between combination meter and transfer control unit
OK or NG
OK >> Replace transfer control unit. Refer to TF-98, "Removal and Installation" .
NG >>

Repair or replace harness or connector.

Replace combination meter. Refer to DI-25, "Removal and Installation of Combination Meter" .
WDIA0080E
Voltage : Battery voltage
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Resistance : Continuity should exist.
LDIA0087E

TF-88
TROUBLE DIAGNOSES FOR SYMPTOMS
Revision: August 20072004 QX56
Symptom 3. 4WD Shift Indicator Lamp Does Not Turn OFF (When 4WD shift
switch is set from 4H to 4LO, all the 4WD shift indicator lamps do not turn off)
EDS0018G
1. CHECK ATP SWITCH CIRCUIT
Check ATP switch circuit.
Refer to TF-69, "
Diagnostic Procedure" .
OK or NG
OK >> GO TO 2.
NG >> Check, repair or replace faulty parts.
2. CHECK PROCEDURE FROM THE BEGINNING AGAIN
Check again.
OK or NG
OK >> Inspection End.
NG >> Recheck each connector pin terminals for damage or loose connection.
WDIA0071E

TROUBLE DIAGNOSES FOR SYMPTOMS
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Revision: August 20072004 QX56
Symptom 4. ATP Warning Lamp Does Not Turn ON (When 4WD shift switch is
set from 4H to 4LO with the A/T selector lever in P position, the ATP warning
lamp does not turn on)
EDS0018H
1. CHECK ATP SWITCH CIRCUIT
Check ATP switch circuit.
Refer to TF-69, "
ATP SWITCH, WAIT DETECTION SWITCH AND
NEUTRAL-4LO SWITCH" .
OK or NG
OK >> GO TO 2.
NG >> Check, repair or replace faulty parts.
2. CHECK COMBINATION METER
Check the combination meter. Refer to DI-17, "
How to Proceed With Trouble Diagnosis"
OK or NG
OK >> Replace transfer control unit. Refer to TF-98, "Removal and Installation" .
NG >> Replace combination meter. Refer to DI-25, "
Removal and Installation of Combination Meter" .
WDIA0103E

TROUBLE DIAGNOSES FOR SYMPTOMS
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Revision: August 20072004 QX56
3. CHECK 4LO INDICATOR LAMP CIRCUIT AND COMBINATION METER
Check the following.

Combination meter. Refer to DI-17, "How to Proceed With Trouble Diagnosis" .

Continuity between ignition switch and combination meter

Continuity between combination meter and transfer control unit

Condition of ATP and neutral-4LO switch circuit. Refer to TF-69, "ATP SWITCH, WAIT DETECTION
SWITCH AND NEUTRAL-4LO SWITCH" .
OK or NG
OK >> Replace transfer control unit. Refer to TF-98, "Removal and Installation" .
NG >>

Repair or replace harness or connector.

Replace combination meter. Refer to DI-25, "Removal and Installation of Combination Meter" .

Replace ATP or neutral-4LO switch.
Symptom 6. 4WD Shift Indicator Lamp Does Not Indicate “LOCK” (When 4WD
shift switch is set to “4H”, 4WD shift indicator lamp does not indicate “LOCK”)
EDS0018J
1. CHECK 4WD WARNING LAMP
Is 4WD warning lamp turned ON?
Ye s o r N o
Yes >> Refer to TF-27, "Trouble Diagnosis without CONSULT-
II" .
No >> GO TO 2.
2. CHECK NEUTRAL-4LO, WAIT DETECTION AND ATP SWITCH CIRCUITS
Check neutral-4LO, wait detection and ATP switch circuits. Refer to TF-69, "
ATP SWITCH, WAIT DETECTION
SWITCH AND NEUTRAL-4LO SWITCH" .
OK or NG
OK >> GO TO 3.
NG >> Check, repair or replace faulty parts.
3. CHECK PROCEDURES FROM THE BEGINNING AGAIN
Check again.
OK or NG
OK >> Inspection End.
NG >> Recheck each connector pin terminals for damage or loose connection.
WDIA0071E

TROUBLE DIAGNOSES FOR SYMPTOMS
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Revision: August 20072004 QX56
Symptom 8. Tight Corner Braking Symptom (Tight Corner Braking Symptom
Occurs-Hydraulic System Failure)
EDS0018L
1. CHECK INPUT SIGNAL
With CONSULT-II
1. Select “ECU INPUT SIGNALS” in Data Monitor.
2. Put A/T selector lever in D.
3. Turn 4WD shift switch to 4H and back to 2WD while reading out
ON/OFF status of "CL PRES SW".
Without CONSULT-II
Check voltage between transfer control unit harness connector E143
terminal 34 (BR) and ground.
Refer to TF-55, "
TRANSFER CONTROL UNIT INSPECTION
TABLE" .
OK or NG
OK >> Disassemble transfer unit and check the following.

Control valve assembly

4WD solenoid valve

2-4WD shift solenoid valve

Clutch piston

Clutch assembly
NG >> GO TO 2.
2. CHECK CLUTCH PRESSURE SWITCH CIRCUIT
Check clutch pressure switch circuit.
Refer to TF-72, "
Diagnostic Procedure" .
OK or NG
OK >> GO TO 3.
NG >> Check, repair or replace faulty parts.
3. CHECK PROCEDURES FROM THE BEGINNING AGAIN
Check again.
OK or NG
OK >> Inspection End.
NG >> Recheck each connector pin terminals for damage or loose connection.
WDIA0087E