INFINITI QX56 2010 Factory Service Manual

P1826 TRANSFER FLUID TEMPERATUREDLN-69
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YES >> GO TO 4.
NO >> GO TO 2.
2.CHECK HARNESS BETWEEN TRANSF ER CONTROL UNIT AND TRANSFER TERMINAL CORD AS-
SEMBLY
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit har ness connector and transfer terminal cord assembly harness connec-
tor.
3. Check continuity between the following terminals.
- Transfer control unit harness connector E143 terminal 28 and
transfer terminal cord assembly harness connector F56 terminal
3 .
- Transfer control unit harness connector E143 terminal 31 and
transfer terminal cord assembly harness connector F56 terminal
2.
Also check harness for short to ground and short to power.
Are inspection results normal?
YES >> GO TO 3.
NO >> Repair or replace damaged parts.
3.CHECK TRANSFER FLUID TEMPERATURE SENSOR
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 2 and 3.
Are inspection results normal?
YES >> GO TO 4.
NO >> Replace transfer fluid temperature sensor. Refer to DLN-16, "
Component Parts Location".
4.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to DLN-81, "
Reference Value".
Are inspection results normal?
YES >> GO TO 5.
NO >> Check transfer control unit pin terminals for damage or loose connection with harness connector. If any items are damaged, repair or replace damaged parts.
5.CHECK DTC
Drive the vehicle and then perform self-diagnosis.
Are inspection results normal?
YES >> Inspection End.
NO >> Replace transfer control unit. Refer to DLN-130, "
Removal and Installation".
Component InspectionINFOID:0000000005148832
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect transfer terminal cord assembly harness connector.Continuity should exist.
SDIA2743E
Temperature
°C ( °F) Resistance (Approx.)
20 (68) 2.5 kΩ
80 (176) 0.3 kΩ
WDIA0188E
Revision: April 20092010 QX56

DLN-70
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P1826 TRANSFER FLUID TEMPERATURE
3. Check resistance between transfer terminal cord assembly ter-
minals 2 and 3.
4. If the inspection results are abnormal replace the transfer fluid temperature sensor. Refer to DLN-16, "
Component Parts Loca-
tion".
Temperature °C ( °F) Resistance (Approx.)
20 (68) 2.5 kΩ
80 (176) 0.3 kΩ
WDIA0188E
Revision: April 20092010 QX56

P1827 CLUTCH PRESSURE SWITCHDLN-71
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P1827 CLUTCH PRESSURE SWITCH
DescriptionINFOID:0000000005148833
Improper signal from the clutch pressure switch is input due to open or short circuit. Also, a malfunction may
have occured in clutch pressure switch or hydraulic circuit.
DTC LogicINFOID:0000000005148834
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Perform self-diagnosis.
Is DTC P1827 displayed?
YES >> Perform diagnosis procedure. Refer to DLN-71, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000005148835
Regarding Wiring Diagram information, refer to DLN-89, "Wiring Diagram - ALL-MODE 4WD SYSTEM -".
1.CHECK CLUTCH PRESSURE SWITCH SIGNAL
With CONSULT-III1. Start engine.
2. Select DATA MONITOR mode for ALL MODE AWD/4WD with CONSULT-III.
3. Read out ON/OFF switching action of the CL PRES SW while operating 4WD shift switch.
Without CONSULT-III
1. Start engine.
DTCCONSULT-III Diagnostic item is detected when... Reference
[P1827] CLUTCH PRES SW • Improper signal from clutch pressure
switch is input due to open or short cir-
cuit.
• Malfunction occurs in clutch pressure switch or hydraulic circuit. Refer to DLN-71
.
Condition
Display value
• Ignition switch: ON
• A/T selector lever D posi- tion 4WD shift switch: AUTO or 4H (Wait
function is not operating.)
ON
Ignition switch: ON 4WD shift switch: 2WD (Wait func-
tion is not operating.) OFF
Revision: April 20092010 QX56

DLN-72
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P1827 CLUTCH PRESSURE SWITCH
2. Check voltage between transfer control unit harness connector
terminals and ground.
Are inspection results normal?
YES >> GO TO 5.
NO >> GO TO 2.
2.CHECK HARNESS BETWEEN TRANSFER CONT ROL 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 and transfer terminal cord assembly har-
ness connector F56 terminal 7
Also check harness for short to ground and short to power.
Are inspection results normal?
YES >> GO TO 3.
NO >> Repair or replace damaged parts.
3.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to DLN-81, "
Reference Value".
Are inspection results normal?
YES >> GO TO 4.
NO >> Check transfer control unit pin terminals for damage or loose connection with the harness connec- tor. If any items are damaged, repair or replace damaged parts.
4.CHECK CLUTCH PRESSURE SWITCH
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Remove clutch pressure switch. Refer to DLN-16, "
Component Parts Location".
3. Push and release clutch pressure switch and check continuity between terminal 7 and ground.
Are inspection results normal?
YES >> GO TO 5.
NO >> Replace clutch pressure switch.
5.CHECK DTC
Perform the self-diagnosis, after driving a vehicle for a while.
Are inspection results normal?
Connector Terminal ConditionVoltage
(Approx.)
E143 34 -
Ground • Ignition switch: ON
• A/T selector lever D
position 4WD shift switch:
AUTO or 4H (Wait
function is not op-
erating.)
0V
Ignition switch: ON 4WD shift switch:
2WD (Wait function
is not operating.)Battery
voltage
SDIA2746E
Continuity should exist.
SDIA2747E
Terminal
Condition Continuity
7 -
Ground Push clutch pressure switch
Yes
Release clutch pressure switch No
WDIA0171E
Revision: April 20092010 QX56

P1827 CLUTCH PRESSURE SWITCHDLN-73
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YES >> GO TO 6.
NO >> Replace transfer control unit. Refer to DLN-130, "
Removal and Installation".
6.CRUISE TEST
Perform cruise test. Refer to DLN-7, "
Preliminary Check".
Are inspection results normal?
YES >> Inspection End.
NO >> Perform the applicable trouble diagnosis.
Component InspectionINFOID:0000000005148836
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Remove clutch pressure switch. Refer to DLN-16, "
Component Parts Location".
3. Push and release clutch pressure switch and check continuity between terminal 7 and ground.
4. If the inspection results are abnormal replace the clutch pres- sure switch.
Terminal Condition Continuity
7 - Ground Push clutch pressure switch
Yes
Release clutch pressure switch No
WDIA0171E
Revision: April 20092010 QX56

DLN-74
< COMPONENT DIAGNOSIS >[ATX14B]
P1828 LINE PRESSURE SWITCH
P1828 LINE PRESSURE SWITCH
DescriptionINFOID:0000000005148837
Improper signal from line pressure switch is input due to open or short circuit. Also, a malfunction may have
occured in the line pressure switch or hydraulic circuit.
DTC LogicINFOID:0000000005148838
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Perform self-diagnosis.
Is DTC P1828 displayed?
YES >> Perform diagnosis procedure. Refer to DLN-74, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000005148839
Regarding Wiring Diagram information, refer to DLN-89, "Wiring Diagram - ALL-MODE 4WD SYSTEM -".
1.CHECK LINE PRESSURE SWITCH SIGNAL
With CONSULT-III1. Start engine.
2. Select DATA MONITOR mode for ALL MODE AWD/4WD with CONSULT-III.
3. Read out ON/OFF switching action of LINE PRES SW while operating 4WD shift switch.
Without CONSULT-III
1. Start engine.
DTCCONSULT-III Diagnostic item is detected when... Reference
[P1828] LINE PRES SW • Improper signal from line pressure
switch is input due to open or short cir-
cuit.
• Malfunction occurs in line pressure switch or hydraulic circuit. Refer to
DLN-74
.
Condition Display value
• A/T selector lever D position
• 4WD shift switch: AUTO ON
• Except the above
• The vehicle has been left at room temperature for 5
minutes and more with ig-
nition switch in OFF posi-
tion. • Ignition switch: ON
• A/T selector lever: P or N position
• 4WD shift switch: other than
AUTO OFF
Revision: April 20092010 QX56

P1828 LINE PRESSURE SWITCHDLN-75
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2. Check voltage between transfer control unit harness connector terminals and ground.
Are inspection results normal?
YES >> GO TO 5.
NO >> GO TO 2.
2.CHECK HARNESS BETWEEN TRAN SFER 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 and transfer terminal cord assembly har-
ness connector F56 terminal 1.
Also check harness for short to ground and short to power.
Are inspection results normal?
YES >> GO TO 3.
NO >> Repair or replace damaged parts.
3.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to DLN-81, "
Reference Value".
Are inspection results normal?
YES >> GO TO 4.
NO >> Check the following. If any items are damaged, repair or replace damaged parts. • Transfer control unit pin terminals for damage or loose connection with harness connector.
• Transfer control unit. Refer to DLN-130, "
Removal and Installation".
4.CHECK LINE PRESSURE SWITCH
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Remove line pressure switch. Refer to DLN-16, "
Component Parts Location".
3. Push and release line pressure switch and check continuity between terminal 1 and ground.
Are inspection results normal?
YES >> GO TO 5.
NO >> Replace line pressure switch.
Connector Terminal ConditionVoltage
(Approx.)
E143 35 -
Ground • A/T selector lever D
position 4WD shift switch:
AUTO
0V
• 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 le- ver: P or N posi-
tion
• 4WD shift switch: other
than AUTO Battery
voltage
SDIA2751E
Continuity should exist.
SDIA2752E
Terminal
Condition Continuity
1 -
Ground Push line pressure switch
Yes
Release line pressure switch No
WDIA0172E
Revision: April 20092010 QX56

DLN-76
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P1828 LINE PRESSURE SWITCH
5.CHECK DTC
Perform the self-diagnosis, after driving a vehicle for a while.
Are inspection results normal?
YES >> GO TO 6.
NO >> Replace transfer control unit. Refer to DLN-130, "
Removal and Installation".
6.CRUISE TEST
Perform cruise test. Refer to DLN-7, "
Preliminary Check".
Are inspection results normal?
YES >> Inspection End.
NO >> Perform the applicable trouble diagnosis.
Component InspectionINFOID:0000000005148840
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Remove line pressure switch. Refer to DLN-16, "
Component Parts Location".
3. Push and release line pressure switch and check continuity between terminal 1 and ground.
4. If the inspection results are abnormal, replace the line pressure switch.
Terminal Condition Continuity
1 - Ground Push line pressure switch
Yes
Release line pressure switch No
WDIA0172E
Revision: April 20092010 QX56

P1829 THROTTLE POSITION SIGNAL (ECM)
DLN-77
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P1829 THROTTLE POSITION SIGNAL (ECM)
DescriptionINFOID:0000000005148841
Malfunction is detected in accelerator pedal position si gnal that is output from ECM through CAN communica-
tion. Also, the signal voltage from accelerator pedal position sensor may be abnormally high or low.
DTC LogicINFOID:0000000005148842
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Perform self-diagnosis.
Is DTC P1829 displayed?
YES >> Perform diagnosis procedure. Refer to DLN-77, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000005148843
1.CHECK DTC WITH ECM
Perform self-diagnosis with ECM. Refer to EC-63, "
CONSULT-III Function (ENGINE)".
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 DLN-81, "
Reference Value".
Are inspection results normal?
YES >> GO TO 3.
NO >> 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.
Are inspection results normal?
YES >> Inspection End.
NO >> Perform self-diagnosis with ECM again.
DTC CONSULT-III Diagnostic item is detected when... Reference
[P1829] THROTTLE POSI SEN • Malfunction is detected in accelerator
pedal position signal that is output
from ECM through CAN communica-
tion.
• Signal voltage from accelerator pedal position sensor is abnormally high or
low. Refer to DLN-77
.
Revision: April 20092010 QX56

DLN-78
< COMPONENT DIAGNOSIS >[ATX14B]
P1830 ABS OPERATION SIGNAL (ABS)
P1830 ABS OPERATION SIGNAL (ABS)
DescriptionINFOID:0000000005148844
Malfunction is detected in ABS operation signal that is
output from ABS actuator and electric unit (control unit)
through CAN communication.
DTC LogicINFOID:0000000005148845
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Perform self-diagnosis.
Is DTC P1830 displayed?
YES >> Perform diagnosis procedure. Refer to DLN-78, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000005148846
1.CHECK DTC WITH ABS ACTUATOR AN D ELECTRIC UNIT (CONTROL UNIT)
Perform self-diagnosis with ABS actuator and electric unit (control unit). Refer to BRC-23, "
CONSULT-III
Function (ABS)".
Is any malfunction detec ted 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 DLN-81, "
Reference Value".
Are the inspection results normal?
YES >> GO TO 3.
NO >> Check transfer control unit pin terminals fo r 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.
Are the inspection results normal?
YES >> Inspection End.
NO >> Perform self-diagnosis with ABS actuator and electric unit (control unit) again.
DTC CONSULT-III Diagnostic item is detected when... Reference
[P1830] ABS OP SIG Malfunction is detect
ed in ABS operation
signal that is outp ut from ABS actuator
and electric unit (control unit) through
CAN communication. Refer to
DLN-78
.
Revision: April 20092010 QX56