2005 INFINITI QX4 engine

TROUBLE DIAGNOSIS FOR SYSTEM
TF-83
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Revision: October 20052005 QX56
2. CHECK GROUND CIRCUIT
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector.
3. Check continuity between transfer control unit harness connec-
tor E142 terminals 3 (B), 6 (B), E143 terminal 45 (B) and ground.
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 3.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
3. CHECK ACTUATOR MOTOR POWER SUPPLY CIRCUIT
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Remove transfer shift high relay and transfer shift low relay. Refer to TF-22, "
Location of Electrical Parts" .
3. Check voltage between transfer shift high relay harness connec-
tor E46 terminal 5 (R), transfer shift low relay harness connector
E47 terminal 5 (R) and ground.
4. Turn ignition switch “ON”. (Do not start engine.)
5. Check voltage between transfer shift high relay harness connec-
tor E46 terminal 5 (R), transfer shift low relay harness connector
E47 terminal 5 (R) and ground.
OK or NG
OK >> GO TO 4.
NG >> Check the following. If any items are damaged, repair or
replace damaged parts.

20A fuse No. 57 located in the fuse and relay box. Refer to PG-4, "POWER SUPPLY ROUTING
CIRCUIT" .

Harness for short or open between battery, transfer shift high relay harness connector E46 ter-
minal 5 (R) and transfer shift low relay harness connector E47 terminal 5 (R). Continuity should exist.
SDIA2691E
Connector Terminal (Wire color) Voltage (Approx.)
E46 5 (R) - Ground
Battery voltage
E47 5 (R) - Ground
SDIA2707E
Connector Terminal (Wire color) Voltage (Approx.)
E46 5 (R) - Ground
Battery voltage
E47 5 (R) - Ground
SDIA2706E

TROUBLE DIAGNOSIS FOR SYSTEM
TF-85
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Revision: October 20052005 QX56
7. PERFORM SELF-DIAGNOSIS (WITH CONSULT-II)
With CONSULT-II
1. Turn ignition switch “ON”. (Do not start engine.)
2. Select “SELF-DIAG RESULTS” mode for “ALL MODE AWD/4WD” with CONSULT-II.
3. Touch “ERASE”.
4. Turn ignition switch “OFF” and wait at least 10 seconds.
5. Perform the self-diagnosis again.
Is the
“SHIFT ACT CIR [P1819]” displayed?
YES >> Replace transfer control unit. Refer to TF-132, "Removal and Installation" .
NO >> Inspection End.
8. PERFORM SELF-DIAGNOSIS (WITHOUT CONSULT-II)
Without CONSULT-II
1. Perform the self-diagnosis and then erase self-diagnostic results. Refer to TF-50, "
SELF-DIAGNOSTIC
PROCEDURE (WITHOUT CONSULT-II)" and TF-53, "ERASE SELF-DIAGNOSIS" .
2. Perform the self-diagnosis again.
Do the self-diagnostic results indicate transfer control device?
YES >> Replace transfer control unit. Refer to TF-132, "Removal and Installation" .
NO >> Inspection End.
Engine Speed Signal (ECM)EDS0 02 IF
DIAGNOSTIC PROCEDURE
1. CHECK DTC WITH ECM
Perform self-diagnosis with ECM. Refer to EC-130, "
SELF-DIAG RESULTS MODE" .
Is any malfunction detected by self-diagnosis?
YES >> Check the malfunctioning system.
NO >> GO TO 2.
2. 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 3.
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.
3. CHECK DTC
Perform the self-diagnosis, after driving a vehicle for a while.
OK or NG
OK >> Inspection End.
NG >> Perform self-diagnosis with ECM again. Refer to EC-130, "
SELF-DIAG RESULTS MODE" .

TF-86
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: October 20052005 QX56
Clutch Pressure SolenoidEDS002IG
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 Content Condition Display value
DUTY SOLENOID [%]Condition of clutch pres-
sure solenoid

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%
Te r m i n a lWire
colorItem Condition Data (Approx.)
10 L/W Transfer dropping resistor

Vehicle stopped

Engine running

A/T selector
lever “N” position

Brake pedal
depressed4WD shift switch: AUTO 4 - 14V
4WD shift switch: 2WD, 4H or 4LO Less than 1V
19 LClutch pressure solenoid
valve

Vehicle stopped

Engine running

A/T selector
lever “N” position

Brake pedal
depressed4WD shift switch: AUTO 1.5 - 3V
4WD shift switch: 2WD, 4H or 4LO Less than 1V

TROUBLE DIAGNOSIS FOR SYSTEM
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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
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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

TROUBLE DIAGNOSIS FOR SYSTEM
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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