2005 INFINITI QX4 check engine
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TF-98
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: October 20052005 QX56
2. Check voltage between transfer control unit harness connector
terminal and ground.
OK or NG
OK >> GO TO 7.
NG >> GO TO 2.
ConnectorTe r m i n a l
(Wire
color)Condition Voltage (Approx.)
E142 14 (LG) -
Ground
Accelera-
tor pedal
depressed
Vehicle
stopped
Engine
running
Brake
pedal
depressed4WD shift switch:
2WDBattery 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
E143 41 (R) -
Ground
Accelera-
tor pedal
depressed
Vehicle
stopped
Engine
running
Brake
pedal
depressed4WD shift switch:
2WD0V
4WD shift switch:
AUTO or 4LO (A/T
selector lever “P” or
“N” position)0V
(Battery voltage
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 voltage
for approx. 2 sec.
after shifting to
“P”.)
4WD shift switch:
4H (Except for A/T
selector lever “P”
position)Battery voltage
SDIA2735E
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TROUBLE DIAGNOSIS FOR SYSTEM
TF-99
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Revision: October 20052005 QX56
2. CHECK TRANSFER MOTOR RELAY POWER SUPPLY CIRCUIT
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Connect transfer control unit harness connector.
3. Disconnect transfer motor relay.
4. Check voltage between transfer motor relay harness connector
terminals and ground.
5. Turn ignition switch “ON”. (Do not start engine.)
6. Check voltage between transfer motor relay harness connector
terminals and ground.
OK or NG
OK >> GO TO 3.
NG >> Check the following. If any items are damaged, repair or
replace damaged parts.
20A fuse No. 58 located in the fuse and relay box. Refer to PG-4, "POWER SUPPLY ROUTING
CIRCUIT" .
10A fuse No. 26 located in the fuse and fusible link box. Refer to PG-4, "POWER SUPPLY
ROUTING CIRCUIT"
Harness for short or open between battery and transfer motor relay harness connector E154
terminal 5 (G/R).
Harness for short or open between transfer shut off relay harness connector E69 terminal 5 (Y/
R) and transfer motor relay harness connector E153 terminal 2 (Y/R).
Battery and ignition switch. Refer to PG-4, "POWER SUPPLY ROUTING CIRCUIT" .
3. CHECK TRANSFER MOTOR RELAY
1. Turn ignition switch “OFF”.
2. Remove transfer motor relay. Refer to TF-22, "
Location of Electrical Parts" .
3. Apply 12V direct current between transfer motor relay terminals
1 and 2.
4. Check continuity between relay terminals 3 and 5.
OK or NG
OK >> GO TO 4.
NG >> Replace the transfer motor relay.
Connector Terminal (Wire color) Voltage (Approx.)
E153 2 (Y/R) - Ground 0V
E154 5 (G/R) - Ground Battery voltage
WDIA0169E
Connector Terminal (Wire color) Voltage (Approx.)
E153 2 (Y/R) - Ground
Battery voltage
E154 5 (G/R) - Ground
WDIA0170E
Condition Continuity
12V direct current supply between terminals 1 and 2 Yes
OFF No
LDIA0098E
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TROUBLE DIAGNOSIS FOR SYSTEM
TF-103
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Revision: October 20052005 QX56
DIAGNOSTIC PROCEDURE
1. CHECK TRANSFER FLUID TEMPERATURE SENSOR 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 “FLUID TEMP SE”.
Without CONSULT-II
1. Start engine.
2. Check voltage between transfer control unit harness connector
terminals and ground.
OK or NG
OK >> GO TO 4.
NG >> GO TO 2.
2. 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 the following terminals.
–Transfer control unit harness connector E143 terminal 28 (B/G)
and transfer terminal cord assembly harness connector F56 ter-
minal 3 (B/G).
–Transfer control unit harness connector E143 terminal 31 (G)
and transfer terminal cord assembly harness connector F56 ter-
minal 2 (G).
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
ConditionDisplay value
(Approx.)
Transfer fluid temperature approx. 20 - 80°C (68 - 176°F) 1.1 - 0.3V
SDIA2741E
ConnectorTe r m i n a l
(Wire
color)ConditionData
(Approx.)
E14328 (B/G)
- GroundAlways 0V
31 (G) -
GroundIgnition switch:
ONTransfer fluid temperature
approx. 20°C (68°F)1.1V
Transfer fluid temperature
approx. 80°C (176°F)0.3V
SDIA2742E
Continuity should exist.
SDIA2743E
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TF-106
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: October 20052005 QX56
DIAGNOSTIC PROCEDURE
1. CHECK CLUTCH 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 the “CL 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 CLUTCH 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 34 (BR) and transfer terminal cord assembly
harness connector F56 terminal 7 (BR)
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
Ignition switch: ON
A/T selector lever “D”
position4WD shift switch: AUTO or 4H
(“Wait” function is not operating.)ON
Ignition switch: ON4WD shift switch: 2WD (“Wait”
function is not operating.)OFF
ConnectorTerminal
(Wire
color)ConditionVoltage
(Approx.)
E14334 (BR) -
Ground
Ignition switch: ON
A/T selector lever
“D” position4WD shift switch:
AUTO or 4H
(“Wait” function is
not operating.)0V
Ignition switch: ON4WD shift switch:
2WD (“Wait” func-
tion is not operat-
ing.)Battery
voltage
WDIA0141E
SDIA2746E
Continuity should exist.
SDIA2747E
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TROUBLE DIAGNOSIS FOR SYSTEM
TF-109
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Revision: October 20052005 QX56
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
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TROUBLE DIAGNOSIS FOR SYSTEM
TF-113
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Revision: October 20052005 QX56
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
Page 3257 of 3419
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
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TROUBLE DIAGNOSIS FOR SYSTEM
TF-115
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Revision: October 20052005 QX56
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