4WD INFINITI QX4 2005 Factory Service Manual

TF-108
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: October 20052005 QX56
Line Pressure SwitchEDS0 02 IL
CONSULT-II REFERENCE VALUE IN DATA MONITOR MODE
Data are reference value.
TRANSFER CONTROL UNIT TERMINALS AND REFERENCE VALUE
Data are reference value and are measured between each terminal and ground.
CAUTION:
When using a circuit tester to measure voltage for inspection, be sure not to extend forcibly any connector terminals.Monitored item [Unit] Content Condition Display value
LINE PRES SW [ON/
OFF]Condition of line pressure
switch

A/T selector lever “D” position

4WD shift switch: 2WD, AUTO or 4HON

Except the above

The vehicle has been
left at room tempera-
ture for 5 minutes and
more with ignition
switch in “OFF” posi-
tion.
Ignition switch: ON

A/T selector lever: "P"
or "N" position

4WD shift switch: other
than AUTOOFF
TerminalWire
colorItem Condition Data (Approx.)
35 BR/W Line pressure switch

Ignition switch: ON

A/T selector lever “D” posi-
tion
4WD shift switch: AUTO 0V

Except the above

The vehicle has been left at
room temperature for 5 min-
utes and more with ignition
switch in “OFF” position.

Ignition switch: ON

A/T selector lever: "P" or "N"
position

4WD shift switch: other than
AUTOBattery voltage

TROUBLE DIAGNOSIS FOR SYSTEM
TF-109
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DIAGNOSTIC PROCEDURE
1. CHECK LINE PRESSURE SWITCH SIGNAL
With CONSULT-II
1. Start engine.
2. Select “DATA MONITOR” mode for “ALL MODE AWD/4WD” with CONSULT-II.
3. Read out ON/OFF switching action of “LINE PRES SW” while
operating 4WD shift switch.
Without CONSULT-II
1. Start engine.
2. Check voltage between transfer control unit harness connector
terminals and ground.
OK or NG
OK >> GO TO 5.
NG >> GO TO 2.
2. CHECK HARNESS BETWEEN TRANSFER CONTROL UNIT AND LINE PRESSURE SWITCH
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and the transfer terminal cord assembly harness con-
nector.
3. Check continuity between transfer control unit harness connec-
tor E143 terminal 35 (BR/W) and transfer terminal cord assem-
bly harness connector F56 terminal 1 (BR/W).
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
Condition Display value

A/T selector lever “D” position

4WD shift switch: AUTOON

Except the above

The vehicle has been left
at room temperature for 5
minutes and more with
ignition switch in “OFF”
position.
Ignition switch: ON

A/T selector lever: "P" or "N"
position

4WD shift switch: other than
AUTOOFF
ConnectorTe r m i n a l
(Wire
color)ConditionVoltage
(Approx.)
E14335 (BR/
W) -
Ground

A/T selector lever
“D” position4WD shift switch:
AUTO0V

Except the above

The vehicle has
been left at room
temperature for 5
minutes and more
with ignition switch
in “OFF” position.

Ignition switch:
ON

A/T selector
lever: "P" or "N"
position

4WD shift
switch: other
than AUTOBattery
voltage
WDIA0142E
SDIA2751E
Continuity should exist.
SDIA2752E

TROUBLE DIAGNOSIS FOR SYSTEM
TF-113
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CAN Communication LineEDS002IQ
DIAGNOSTIC PROCEDURE
1. CHECK CAN COMMUNICATION CIRCUIT
With CONSULT-II
1. Turn ignition switch “ON” and start engine.
2. Select “SELF-DIAG RESULTS” mode for “ALL MODE AWD/4WD” within CONSULT-II.
3. Perform the self-diagnosis.
Is the
“CAN COMM CIRCUIT [U1000]” displayed?
YES >> Print CONSULT-II screen and go to LAN-3, "Precautions
When Using CONSULT-II" .
NO >> Inspection End.
ATP SwitchEDS002IR
CONSULT-II REFERENCE VALUE IN DATA MONITOR MODE
Data are reference value.
TRANSFER CONTROL UNIT TERMINALS AND REFERENCE VALUE
Data are reference value and are measured between each terminal and ground.
CAUTION:
When using a circuit tester to measure voltage for inspection, be sure not to extend forcibly any connector terminals.
SDIA1850E
Monitored item [Unit] Content Condition Display value
ATP SWITCH [ON/OFF] Condition of ATP switch

Vehicle stopped

Engine running

A/T selector lever “N"

Brake pedal depressed4WD shift switch
: 4H to 4LO or 4LO to 4H
(While actuator motor is
operating.) ON
Except the above OFF
Te r m i n a lWire
colorItem Condition Data (Approx.)
40 L ATP switch

Vehicle stopped

Engine running

A/T selector
lever “N"

Brake pedal
depressed4WD shift switch: 4H to 4LO or 4LO to 4H
(While actuator motor is operating.)0V
Except the above Battery voltage

TF-114
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: October 20052005 QX56
DIAGNOSTIC PROCEDURE
1. CHECK ATP SWITCH SIGNAL
With CONSULT-II
1. Start engine.
2. Select “DATA MONITOR” mode for “ALL MODE AWD/4WD” with CONSULT-II.
3. Read out the value of “ATP SWITCH”.
Without CONSULT-II
1. Start engine.
2. Check voltage between transfer control unit harness connector
terminal and ground.
OK or NG
OK >> GO TO 5.
NG >> GO TO 2.
2. CHECK HARNESS BETWEEN TRANSFER CONTROL UNIT AND ATP SWITCH
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and the ATP switch harness connector.
3. Check continuity between transfer control unit harness connec-
tor E143 terminal 40 (L) and ATP switch harness connector F55
terminal 8 (L/Y).
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
Condition Display value

Vehicle stopped

Engine running

A/T selector lever
“N"

Brake pedal
depressed4WD shift switch
: 4H to 4LO or 4LO to 4H
(While actuator motor is operating.) ON
Except the above OFF
SDIA2391E
ConnectorTe r m i n a l
(Wire
color)ConditionVoltage
(Approx.)
E14340 (L) -
Ground

Vehicle stopped

Engine running

A/T selector lever
“N"

Brake pedal
depressed4WD shift switch: 4H
to 4LO or 4LO to 4H
(While actuator motor
is operating.)0V
Except the aboveBattery
voltageSDIA2755E
Continuity should exist.
SDIA2756E

TROUBLE DIAGNOSIS FOR SYSTEM
TF-115
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3. CHECK GROUND CIRCUIT
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect ATP switch harness connector.
3. Check continuity between ATP switch harness connector F55
terminal 9 (B) and ground.
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
4. CHECK ATP SWITCH
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect ATP switch harness connector.
3. Remove ATP switch. Refer to TF-22, "
Location of Electrical Parts" .
4. Push and release ATP switch and check continuity between ATP
switch terminals 8 and 9.
OK or NG
OK >> GO TO 5.
NG >> Replace ATP switch. Refer to TF-22, "
Location of Elec-
trical Parts" .
5. CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to TF-36, "
Transfer Control Unit Input/Output Signal Ref-
erence Values" .
OK or NG
OK >> GO TO 6.
NG >> Check transfer control unit pin terminals for damage or loose connection with harness connector.
If any items are damaged, repair or replace damaged parts.
6. CHECK ATP WARNING LAMP
1. Turn ignition switch “ON”. (Do not start engine.)
2. Move A/T selector lever to "P" position.
3. Set 4WD shift switch from "4H" to "4LO" or "4LO" to "4H".
Does ATP warning lamp turn ON while switching?
YES >> GO TO TF-125, "ATP Warning Lamp Turns ON" .
NO >> Inspection End.
COMPONENT INSPECTION
1. Turn ignition switch “OFF”. (Stay for at least 5 second.)
2. Disconnect ATP switch harness connector.
3. Remove ATP switch. Refer to TF-22, "
Location of Electrical Parts" . Continuity should exist.
SDIA2394E
Terminal Condition Continuity
8 - 9Push ATP switch Yes
Release ATP switch No
SDIA2757E

TROUBLE DIAGNOSIS FOR SYMPTOMS
TF-117
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Revision: October 20052005 QX56
TROUBLE DIAGNOSIS FOR SYMPTOMSPFP:00007
4WD Shift Indicator Lamp and 4LO Indicator Lamp Do Not Turn ONEDS002HM
SYMPTOM:
4WD shift indicator lamp and 4LO indicator lamp do not turn ON for approx. 1 second when turning
ignition switch to “ON”.
DIAGNOSTIC PROCEDURE
1. CHECK TRANSFER CONTROL UNIT POWER SUPPLY CIRCUIT
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Connect transfer control unit harness connector.
3. Check voltage between transfer control unit harness connector
terminals and ground.
4. Turn ignition switch “ON”. (Do not start engine.)
5. Check voltage between transfer control unit harness connector
terminals and ground.
OK or NG
OK >> GO TO 2.
NG >> Check the following. If any items are damaged, repair or replace damaged parts.

10A fuses No. 26 located in fuse and fusible link box and No. 59 located in the fuse and relay
box. Refer to PG-4, "
POWER SUPPLY ROUTING CIRCUIT" .

20A fuse No. 53 located in the IPDM E/R. Refer to PG-4, "POWER SUPPLY ROUTING CIR-
CUIT" .

Harness for short or open between battery and transfer control unit harness connector termi-
nals 47.

Harness for short or open between battery and transfer control unit harness connector terminal
29.

Harness for short or open between battery and transfer shut off relay harness connector E69
terminal 1 (G), and 3 (G).

Harness for short or open between transfer shut off relay harness connector E69 terminal 2
(SB) and transfer control unit harness connector terminal 30.

Harness for short or open between transfer shut off relay harness connector E69 terminal 5 (Y/
R) and transfer control unit harness connector terminals 16 (Y/R) and 22 (Y/R).

Battery and ignition switch. Refer to PG-4, "POWER SUPPLY ROUTING CIRCUIT" .

Transfer shut off relay. Refer to TF-57, "COMPONENT INSPECTION" .
Connector Terminal (Wire color) Voltage (Approx.)
E14216 (Y/R) - Ground
0V 22 (Y/R) - Ground
E14329 (L/W) - Ground
30 (SB) - Ground
Battery voltage
47 (W) - Ground
WDIA0165E
Connector Terminal (Wire color) Voltage (Approx.)
E14216 (Y/R) - Ground
Battery voltage 22 (Y/R) - Ground
E14329 (L/W) - Ground
30 (SB) - Ground 0V
47 (W) - Ground Battery voltage
WDIA0166E

TROUBLE DIAGNOSIS FOR SYMPTOMS
TF-121
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Revision: October 20052005 QX56
4WD Warning Lamp Does Not Turn ONEDS002HN
SYMPTOM:
4WD warning lamp does not turn ON when turning ignition switch to “ON”.
DIAGNOSTIC PROCEDURE
1. CHECK TRANSFER CONTROL UNIT POWER SUPPLY CIRCUIT
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Connect transfer control unit harness connector.
3. Check voltage between transfer control unit harness connector
terminals and ground.
4. Turn ignition switch “ON”. (Do not start engine.)
5. Check voltage between transfer control unit harness connector
terminals and ground.
OK or NG
OK >> GO TO 4.
NG >> Check the following. If any items are damaged, repair or replace damaged parts.

10A fuses No. 26 located in fuse and fusible link box and No. 59 located in the fuse and relay
box. Refer to PG-4, "
POWER SUPPLY ROUTING CIRCUIT" .

20A fuse No. 53 located in the IPDM E/R. Refer to PG-4, "POWER SUPPLY ROUTING CIR-
CUIT" .

Harness for short or open between battery and transfer control unit harness connector termi-
nals 47.

Harness for short or open between battery and transfer control unit harness connector terminal
29.

Harness for short or open between battery and transfer shut off relay harness connector E69
terminal 1 (G), and 3 (G).

Harness for short or open between transfer shut off relay harness connector E69 terminal 2
(SB) and transfer control unit harness connector terminal 30.

Harness for short or open between transfer shut off relay harness connector E69 terminal 5 (Y/
R) and transfer control unit harness connector terminals 16 (Y/R) and 22 (Y/R).

Battery and ignition switch. Refer to PG-4, "POWER SUPPLY ROUTING CIRCUIT" .

Transfer shut off relay. Refer to TF-57, "COMPONENT INSPECTION" .
Connector Terminal (Wire color) Voltage (Approx.)
E14216 (Y/R) - Ground
0V 22 (Y/R) - Ground
E14329 (L/W) - Ground
30 (SB) - Ground
Battery voltage
47 (W) - Ground
WDIA0165E
Connector Terminal (Wire color) Voltage (Approx.)
E14216 (Y/R) - Ground
Battery voltage 22 (Y/R) - Ground
E14329 (L/W) - Ground
30 (SB) - Ground 0V
47 (W) - Ground Battery voltage
WDIA0166E

TROUBLE DIAGNOSIS FOR SYMPTOMS
TF-123
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4. CHECK HARNESS BETWEEN TRANSFER CONTROL UNIT AND COMBINATION METER
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and combination meter harness connector.
3. Check continuity between the following terminals.
–Transfer control unit harness connector E142 terminal 5 (W/B)
and combination meter harness connector M24 terminal 34 (W/
B).
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair or replace damaged parts.
5. CHECK INDICATOR LAMP CIRCUIT
1. Connect combination meter harness connector.
2. Disconnect transfer control unit harness connector.
3. Turn ignition switch “ON”. (Do not start engine.)
4. Ground the following terminal using suitable wiring.
–Transfer control unit harness connector E142 terminal 5 (W/B)
and ground.
Does 4WD warning lamp turn on?
OK >> GO TO 6.
NG >> Replace combination meter. Refer to IP-13, "
Combina-
tion Meter" .
6. SYMPTOM CHECK
Check again.
OK or NG
OK >> Inspection End.
NG >> GO TO 7.
7. CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to TF-36, "
Transfer Control Unit Input/Output Signal Ref-
erence Values" .
OK or NG
OK >> Inspection End.
NG >> Check transfer control unit pin terminals for damage or loose connection with harness connector.
If any items are damaged, repair or replace damaged parts.
4WD Shift Indicator Lamp or 4LO Indicator Lamp Does Not ChangeEDS002HO
SYMPTOM:
4WD shift indicator lamp or 4LO indicator lamp does not change when switching 4WD shift switch.Continuity should exist.
WDIA0154E
SDIA2774E

TF-124
TROUBLE DIAGNOSIS FOR SYMPTOMS
Revision: October 20052005 QX56
DIAGNOSTIC PROCEDURE
1. CONFIRM THE SYMPTOM
Confirm 4WD shift indicator lamp and 4LO indicator lamp turn on when ignition switch is turned to ON.
Do 4WD shift indicator lamp and 4LO indicator lamp turn on?
YES >> GO TO 2.
NO >> Go to TF-117, "
4WD Shift Indicator Lamp and 4LO Indicator Lamp Do Not Turn ON" .
2. CHECK SYSTEM FOR 4WD SHIFT SWITCH
Perform trouble diagnosis for 4WD shift switch system. Refer to TF-62, "
4WD Shift Switch" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3. CHECK SYSTEM FOR WAIT DETECTION SWITCH
Perform trouble diagnosis for wait detection switch system. Refer to TF-66, "
Wait Detection Switch" .
OK or NG
OK >> GO TO 4.
NG >> Repair or replace damaged parts.
4. CHECK SYSTEM FOR NEUTRAL-4LO SWITCH
Perform trouble diagnosis for neutral-4LO switch system. Refer to TF-59, "
Neutral-4LO Switch" .
OK or NG
OK >> GO TO 5.
NG >> Repair or replace damaged parts.
5. CHECK SYSTEM FOR ATP SWITCH
Perform trouble diagnosis for ATP switch system. Refer to TF-113, "
AT P S w i t c h" .
OK or NG
OK >> GO TO 6.
NG >> Repair or replace damaged parts.
6. CHECK SYSTEM FOR 2-4WD SOLENOID
Perform trouble diagnosis for 2-4WD solenoid system. Refer to TF-91, "
2-4WD Solenoid" .
OK or NG
OK >> GO TO 7.
NG >> Repair or replace damaged parts.
7. CHECK SYSTEM FOR TRANSFER CONTROL DEVICE
Perform trouble diagnosis for transfer control device system. Refer to TF-81, "
Transfer Control Device" .
OK or NG
OK >> GO TO 8.
NG >> Repair or replace damaged parts.
8. CHECK SYSTEM FOR ACTUATOR MOTOR
Perform trouble diagnosis for actuator motor system. Refer to TF-70, "
Actuator Motor" .
OK or NG
OK >> GO TO 9.
NG >> Repair or replace damaged parts.

TROUBLE DIAGNOSIS FOR SYMPTOMS
TF-125
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9. CHECK SYSTEM FOR ACTUATOR POSITION SWITCH
Perform trouble diagnosis for actuator position switch system. Refer to TF-77, "
Actuator Position Switch" .
OK or NG
OK >> GO TO 10.
NG >> Repair or replace damaged parts.
10. SYMPTOM CHECK
Check again.
OK or NG
OK >> Inspection End.
NG >> GO TO 11.
11 . CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to TF-36, "
Transfer Control Unit Input/Output Signal Ref-
erence Values" .
OK or NG
OK >> GO TO 12.
NG >> Check transfer control unit pin terminals for damage or loose connection with harness connector.
If any items are damaged, repair or replace damaged parts.
12. CHECK TRANSFER INNER PARTS
1. Disassemble transfer assembly. Refer to TF-144, "
Disassembly and Assembly" .
2. Check transfer inner parts.
OK or NG
OK >> Inspection End.
NG >> Repair or replace damaged parts.
ATP Warning Lamp Turns ONEDS002HP
SYMPTOM:
ATP warning lamp turns ON when 4WD shift switch from “4H” to “4LO” or “4LO” to “4H” with A/T
selector lever “N” to “P” position.
DIAGNOSTIC PROCEDURE
1. CHECK SYSTEM FOR CAN COMMUNICATION LINE
Perform self-diagnosis. Refer to TF-50, "
Self-diagnostic Procedure" .
Do the self-diagnostic results indicate CAN communication?
YES >> Perform trouble diagnosis for CAN communication line. Refer to TF-113, "CAN Communication
Line" .
NO >> GO TO 2.
2. CHECK SYSTEM FOR 4WD SHIFT SWITCH
Perform trouble diagnosis for 4WD shift switch system. Refer to TF-62, "
4WD Shift Switch" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3. CHECK SYSTEM FOR PNP SWITCH SIGNAL
Perform trouble diagnosis for PNP switch signal system. Refer to TF-69, "
PNP Switch Signal (TCM)" .
OK or NG
OK >> GO TO 4.
NG >> Repair or replace damaged parts.