2005 INFINITI QX4 4WD

TROUBLE DIAGNOSIS FOR SYSTEM
TF-87
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Revision: October 20052005 QX56
DIAGNOSTIC PROCEDURE
1. CHECK CLUTCH PRESSURE 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 “DUTY SOLENOID”.
Without CONSULT-II
1. Start engine.
2. Check voltage between transfer control unit harness connector
terminal and ground.
OK or NG
OK >> GO TO 7.
NG >> GO TO 2.
Condition Display value

Vehicle stopped

Engine running

A/T selector lever “N” position

Brake pedal depressed4WD shift switch: 2WD 4%
4WD shift switch: AUTO 96 - 4%
4WD shift switch: 4H or
4LO4%
SDIA2718E
ConnectorTe r m i n a l
(Wire
color)ConditionVoltage
(Approx.)
E142 10 (L/W)
- Ground

Vehicle stopped

Engine running

A/T selector lever
“N” position

Brake pedal
depressed4WD shift switch:
AUTO4 - 14V
4WD shift switch:
2WD, 4H or 4LOLess
than 1V
19 (L) -
Ground

Vehicle stopped

Engine running

A/T selector lever
“N” position

Brake pedal
depressed4WD shift switch:
AUTO1.5 - 3V
4WD shift switch:
2WD, 4H or 4LOLess
than 1V
SDIA2719E

TROUBLE DIAGNOSIS FOR SYSTEM
TF-91
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Revision: October 20052005 QX56
2-4WD SolenoidEDS002IH
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.
DIAGNOSTIC PROCEDURE
1. CHECK 4WD SHIFT SWITCH SYSTEM
Perform self-diagnosis. Refer to TF-50, "
Self-diagnostic Procedure" .
Is the "4WD MOD SW [P1814]" (with CONSULT-II) or "Flickering pattern: 16 (without CONSULT-II) detected?
YES >> Perform trouble diagnosis for 4WD shift switch. Refer to TF-62, "4WD Shift Switch" .
NO >> GO TO 2.
Monitored item Content Condition Display value
2-4WD SOL [ON/OFF]Condition of 2-4WD shift
solenoid valve

Vehicle stopped

Engine running

A/T selector lever “N”
position

Brake pedal depressed4WD shift switch: 2WD OFF
4WD shift switch: AUTO
ON 4WD shift switch: 4H
4WD shift switch: 4LO
4WD shift switch: AUTO
(“Wait” function is operat-
ing.)OFF
4WD shift switch: 4H
(“Wait” function is operat-
ing.)OFF
2-4WD SOL MON [ON/
OFF]Check signal for transfer
control unit signal output

Vehicle stopped

Engine running

A/T selector lever “N”
position

Brake pedal depressed4WD shift switch: 2WD OFF
4WD shift switch: AUTO
ON 4WD shift switch: 4H
4WD shift switch: 4LO
4WD shift switch: AUTO
(“Wait” function is operat-
ing.)OFF
4WD shift switch: 4H
(“Wait” function is operat-
ing.)OFF
Te r m i n a lWire
colorItem Condition Data (Approx.)
1 GR 2-4WD shift solenoid valve

Vehicle stopped

Engine running

A/T selector
lever “N” position

Brake pedal
depressed4WD shift switch: 2WD 0V
4WD shift switch: AUTO, 4H or 4LO Battery voltage

TF-92
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: October 20052005 QX56
2. CHECK 2-4WD SHIFT SOLENOID 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 “2-4WD SOL” and “2-4WD SOL MON”.
Without CONSULT-II
1. Start engine.
2. Check voltage between transfer control unit harness connector
terminal and ground.
OK or NG
OK >> GO TO 7.
NG >> GO TO 3.
Monitored
itemConditionDisplay
value
2-4WD SOL

Vehicle stopped

Engine running

A/T selector lever “N”
position

Brake pedal
depressed4WD shift switch: 2WD OFF
4WD shift switch: AUTO
ON 4WD shift switch: 4H
4WD shift switch: 4LO
4WD shift switch: AUTO
(“Wait” function is operat-
ing.)OFF
4WD shift switch: 4H (“Wait”
function is operating.)OFF
2-4WD SOL
MON

Vehicle stopped

Engine running

A/T selector lever “N”
position

Brake pedal
depressed4WD shift switch: 2WD OFF
4WD shift switch: AUTO
ON 4WD shift switch: 4H
4WD shift switch: 4LO
4WD shift switch: AUTO
(“Wait” function is operat-
ing.)OFF
4WD shift switch: 4H (“Wait”
function is operating.)OFF
SDIA2727E
ConnectorTe r m i n a l
(Wire
color)ConditionVoltage
(Approx.)
E142 1 (GR) -
Ground

Vehicle stopped

Engine running

A/T selector lever
“N” position

Brake pedal
depressed4WD shift switch:
2WD0V
4WD shift switch:
AUTO, 4H or 4LOBattery
voltageSDIA2728E

TROUBLE DIAGNOSIS FOR SYSTEM
TF-93
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Revision: October 20052005 QX56
3. CHECK 4WD SHIFT SWITCH SIGNAL
1. Turn ignition switch “ON”. (Do not start engine.)
2. Check voltage between transfer control unit harness connector
terminals and ground.
OK or NG
OK >> GO TO 4.
NG >> Check 4WD shift switch. Refer to TF-66, "
COMPONENT INSPECTION" .
4. CHECK HARNESS BETWEEN 4WD SHIFT SWITCH AND TRANSFER TERMINAL CORD ASSEMBLY
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect 4WD shift switch harness connector and transfer terminal cord assembly harness connector.
3. Check continuity between 4WD shift switch harness connector
M141 terminal 4 (G/R) and transfer terminal cord assembly har-
ness connector F56 terminal 5 (G/R).
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 HARNESS BETWEEN TRANSFER CONTROL UNIT AND TRANSFER TERMINAL CORD
ASSEMBLY
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and transfer terminal cord assembly harness connec-
tor.
3. Check continuity between transfer control unit harness connec-
tor E142 terminal 1 (GR) and transfer terminal cord assembly
harness connector F56 terminal 4 (GR).
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 6.
NG >> Repair or replace damaged parts.
ConnectorTe r m i n a l
(Wire color)ConditionVoltage
(Approx.)
M1414 (G/R) -
ground4WD shift switch: AUTO, 4H or 4LO Battery voltage
4WD shift switch: 2WD 0V
SDIA2729E
Continuity should exist.
SDIA2731E
Continuity should exist.
SDIA2732E

TF-94
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: October 20052005 QX56
6. CHECK 2-4WD SOLENOID
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer terminal cord assembly harness connector.
3. Check resistance between transfer terminal cord assembly ter-
minals 4 and 5.
OK or NG
OK >> GO TO 7.
NG >> 2-4WD solenoid is malfunctioning. Refer to TF-22,
"Location of Electrical Parts" .
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 >> GO TO 8.
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.
8. CHECK DTC
Perform the self-diagnosis, after driving a vehicle for a while.
OK or NG
OK >> Inspection End.
NG >> Replace transfer control unit. Refer to TF-132, "
Removal and Installation" .
COMPONENT INSPECTION
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer terminal cord assembly harness connector.
3. Check resistance between transfer terminal cord assembly ter-
minals 4 and 5.
4. If NG, replace the 2-4WD solenoid. Refer to TF-22, "
Location of
Electrical Parts" . 4 - 5 : Approx. 22.8 - 25.2 Ω
WDIA0187E
4 - 5 : Approx. 22.8 - 25.2 Ω
WDIA0187E

TROUBLE DIAGNOSIS FOR SYSTEM
TF-95
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Revision: October 20052005 QX56
Transfer MotorEDS0 02 II
CONSULT-II REFERENCE VALUE IN DATA MONITOR MODE
Data are reference value.
Monitored item Content Condition Display value
MOTOR RELAY [ON/
OFF]Condition of transfer motor
relay

Accelerator pedal
depressed

Vehicle stopped

Engine running

Brake pedal depressed4WD shift switch: 2WD OFF
4WD shift switch: AUTO
or 4LO (A/T selector lever
“P” or “N” position)OFF
("ON" for approx. 2
sec. after shifting to
“P” and “N”.)
4WD shift switch: AUTO
or 4LO (Except for A/T
selector lever “P” or “N”
position)ON
4WD shift switch: 4H (A/T
selector lever “P” posi-
tion)OFF
("ON" for approx. 2
sec. after shifting to
“P”.)
4WD shift switch: 4H
(Except for A/T selector
lever “P” position)ON
MOTOR RELAY MON
[ON/OFF]Check signal for transfer
control unit signal output

Accelerator pedal
depressed

Vehicle stopped

Engine running

Brake pedal depressed4WD shift switch: 2WD OFF
4WD shift switch: AUTO
or 4LO (A/T selector lever
“P” or “N” position)OFF
("ON" for approx. 2
sec. after shifting to
“P” and “N”.)
4WD shift switch: AUTO
or 4LO (Except for A/T
selector lever “P” or “N”
position)ON
4WD shift switch: 4H (A/T
selector lever “P” posi-
tion)OFF
("ON" for approx. 2
sec. after shifting to
“P”.)
4WD shift switch: 4H
(Except for A/T selector
lever “P” position)ON

TF-96
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: October 20052005 QX56
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.Te r m i n a lWire
colorItem Condition Data (Approx.)
14 LG Transfer motor relay

Accelerator
pedal depressed

Vehicle stopped

Engine running

Brake pedal
depressed4WD shift switch: 2WD Battery voltage
4WD shift switch: AUTO or 4LO (A/T
selector lever “P” or “N” position)Battery voltage
(0V for approx.
2 sec. after
shifting to “P”
and “N”.)
4WD shift switch: AUTO or 4LO (Except
for A/T selector lever “P” or “N” position)0V
4WD shift switch: 4H (A/T selector lever
“P” position)Battery voltage
(0V for approx.
2 sec. after
shifting to “P”.)
4WD shift switch: 4H (Except for A/T
selector lever “P” position)0V
41 R Transfer motor relay monitor

Accelerator
pedal depressed

Vehicle stopped

Engine running

Brake pedal
depressed4WD shift switch: 2WD 0V
4WD shift switch: AUTO or 4LO (A/T
selector lever “P” or “N” position)0V
(Battery volt-
age for approx.
2 sec. after
shifting to “P”
and “N”.)
4WD shift switch: AUTO or 4LO (Except
for A/T selector lever “P” or “N” position)Battery voltage
4WD shift switch: 4H (A/T selector lever
“P” position)0V
(Battery volt-
age for approx.
2 sec. after
shifting to “P”.)
4WD shift switch: 4H (Except for A/T
selector lever “P” position)Battery voltage

TROUBLE DIAGNOSIS FOR SYSTEM
TF-97
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Revision: October 20052005 QX56
DIAGNOSTIC PROCEDURE
1. CHECK TRANSFER MOTOR RELAY 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 “MOTOR RELAY” and “MOTOR RELAY
MON”.
Without CONSULT-II
1. Start engine.
Monitored
itemConditionDisplay value
(Approx.)
MOTOR
RELAY

Accelerator
pedal depressed

Vehicle stopped

Engine running

Brake pedal
depressed4WD shift switch: 2WD OFF
4WD shift switch: AUTO or
4LO (A/T selector lever “P” or
“N” position)OFF
("ON" for
approx. 2 sec.
after shifting to
“P” and “N”.)
4WD shift switch: AUTO or
4LO (Except for A/T selector
lever “P” or “N” position)ON
4WD shift switch: 4H (A/T
selector lever “P” position)OFF
("ON" for
approx. 2 sec.
after shifting to
“P”.)
4WD shift switch: 4H (Except
for A/T selector lever “P” posi-
tion)ON
MOTOR
RELAY
MON

Accelerator
pedal depressed

Vehicle stopped

Engine running

Brake pedal
depressed4WD shift switch: 2WD OFF
4WD shift switch: AUTO or
4LO (A/T selector lever “P” or
“N” position)OFF
("ON" for
approx. 2 sec.
after shifting to
“P” and “N”.)
4WD shift switch: AUTO or
4LO (Except for A/T selector
lever “P” or “N” position)ON
4WD shift switch: 4H (A/T
selector lever “P” position)OFF
("ON" for
approx. 2 sec.
after shifting to
“P”.)
4WD shift switch: 4H (Except
for A/T selector lever “P” posi-
tion)ON
SDIA2734E