2010 INFINITI QX56 engine

DLN-46
< COMPONENT DIAGNOSIS >[ATX14B]
P1818 ACTUATOR POSITION SWITCH
P1818 ACTUATOR POSITION SWITCH
DescriptionINFOID:0000000005148807
The actuator position switch detects t
he current actuator motor range. DTC P1818 will set if either of the fol-
lowing occur:
• Improper signal from actuator position switch is input due to open or short circuit.
• Malfunction is detected in actuator position switch.
DTC LogicINFOID:0000000005148808
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Perform self-diagnosis.
Is DTC P1818 detected?
YES >> Perform diagnosis procedure. Refer to DLN-46, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000005148809
Regarding Wiring Diagram information, refer to DLN-89, "Wiring Diagram - ALL-MODE 4WD SYSTEM -".
1.CHECK ACTUATOR POSITION SWITCH SIGNAL
With CONSULT-III
1. Start engine.
2. Select DATA MONITOR mode for ALL MODE AWD/4WD with CONSULT-III.
3. Read out the value of SHIFT POS SW1 and SHIFT POS SW2.
Without CONSULT-III
1. Start engine.
DTCCONSULT-III Diagnostic item is detected when... Reference
[P1818] SHIFT ACT POSI SW • Improper signal from actuator position
switch is input due to open or short cir-
cuit.
• Malfunction is detected in the actuator
position switch. Refer to
DLN-46
.
Monitored item ConditionDisplay value
SHIFT POS SW1 • Vehicle stopped
• Engine running
• A/T selector lever
N position
• Brake pedal de-
pressed 4WD shift switch: 4LO ON
4WD shift switch:
2WD, AUTO or 4H
OFF
SHIFT POS SW2 • Vehicle stopped
• Engine running
• A/T selector lever
N position
• Brake pedal de- pressed 4WD shift switch: 4H,
AUTO or 2WD
ON
4WD shift switch: 4LO OFF
Revision: April 20092010 QX56

P1818 ACTUATOR POSITION SWITCHDLN-47
< COMPONENT DIAGNOSIS > [ATX14B]
C
EF
G H
I
J
K L
M A
B
DLN
N
O P
2. Check voltage between transfer control unit harness connector terminal and ground.
Are the inspection results normal?
YES >> GO TO 5.
NO >> GO TO 2.
2.CHECK HARNESS BETWEEN TRAN SFER CONTROL UNIT AND ACTUATOR POSITION SWITCH
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and the transfer control device (actuator position
switch) harness connector.
3. Check continuity between the following terminals.
- Transfer control unit harness connector E143 terminal 27 and transfer control device (actuator position switch) harness con-
nector F58 terminal 23.
- Transfer control unit harness connector E143 terminal 44 and
transfer control device (actuator position switch) harness con-
nector F58 terminal 20.
Also check harness for short to ground and short to power.
Are the inspection results normal?
YES >> GO TO 3.
NO >> Repair or replace damaged parts.
3.CHECK GROUND CIRCUIT
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect transfer control device (act uator position switch) harness connector.
3. Check continuity between transfer control device (actuator posi- tion switch) harness connector F58 terminal 22 and ground.
Also check harness for short to ground and short to power.
Are the inspection results normal?
YES >> GO TO 4.
NO >> Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK ACTUATOR POSITION SWITCH
1. Remove transfer control device. Refer to DLN-136, "
Removal and Installation".
Connector TerminalConditionVoltage
(Approx.)
E143 27 -
Ground • Vehicle stopped
• Engine running
• A/T selector le-
ver N position
• Brake pedal de- pressed 4WD shift switch: 4H,
AUTO or 2WD
0V
4WD shift switch: 4LO Battery
voltage
44 -
Ground • Vehicle stopped
• Engine running
• A/T selector le-
ver N position
• Brake pedal de- pressed 4WD shift switch: 4LO 0V
4WD shift switch:
2WD, AUTO or 4H
Battery
voltage
SDIA2715E
Continuity should exist.
SDIA2716E
Continuity should exist.
SDIA2717E
Revision: April 20092010 QX56

DLN-50
< COMPONENT DIAGNOSIS >[ATX14B]
P1819 TRANSFER CONTROL DEVICE
4. Turn ignition switch ON. (Do not start engine.)
5. Check voltage between transfer control unit harness connector
terminals and ground.
Are the inspection results normal?
YES >> GO TO 2.
NO >> Check the following. If any items are damaged, repair or replace damaged parts. • 10A fuse (No. 26 located in the fuse and fusible link box).
• Harness for short or open between battery and transfer shut off relay harness connector E69
terminal 1.
• Harness for short or open between transfer shut off relay harness connector E69 terminal 2 and
transfer control unit harness connector E143 terminal 30.
• Harness for short or open between battery and transfer shut off relay harness connector E69 terminal 5.
• Harness for short or open between transfer shut off relay harness connector E69 terminal 3 and transfer control unit harness connector E142 terminal 22.
• Transfer shut off relay. Refer to DLN-23, "
Component Inspection".
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, 6, E143 terminal 45 and ground.
Also check harness for short to ground and short to power.
Are the inspection results normal?
YES >> GO TO 3.
NO >> 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 DLN-16, "
Component Parts Loca-
tion".
3. Check voltage between transfer shift high relay harness connec- tor E46 terminal 5 (A), transfer shift low relay harness connector
E47 terminal 5 (B) and ground.
Connector Terminal Voltage (Approx.)
E142 16 - Ground
Battery voltage
22 - Ground
E143 30 - Ground 0V
SDIA2835E
Continuity should exist.
SDIA2691E
ConnectorTerminal Voltage (Approx.)
A: E46 5 - Ground
Battery voltage
B: E47 5 - Ground
WDIA0310E
Revision: April 20092010 QX56

P1819 TRANSFER CONTROL DEVICEDLN-51
< COMPONENT DIAGNOSIS > [ATX14B]
C
EF
G H
I
J
K L
M A
B
DLN
N
O P
4. Turn ignition switch ON. (Do not start engine.)
5. Check voltage between transfer shift high relay harness connec- tor E46 terminal 5 (A), transfer shift low relay harness connector
E47 terminal 5 (B) and ground.
Are the inspection results normal?
YES >> GO TO 4.
NO >> Check the following. If any items are damaged, repair or replace damaged parts. • 20A fuse (No. 57 located in the fuse and relay box).
• Harness for short or open between battery, transfer shift high relay harness connector E46 ter-minal 5 and transfer shift low relay harness connector E47 terminal 5.
4.CHECK HARNESS BETWEEN TRAN SFER CONTROL UNIT AND TRANSFER SHIFT RELAY
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit har ness connector and transfer control device (actuator motor) harness
connector.
3. Remove transfer shift high relay and transfer shift low relay.
4. Check continuity between the following terminals.
- Transfer control unit harness connector E143 (A) terminal 33 and transfer shift high relay harness connector E46 (B) terminal
3.
- Transfer control unit harness connector E143 (A) terminal 42 and transfer shift low relay harness connector E47 (C) terminal
3.
Also check harness for short to ground and short to power.
Are the inspection results normal?
YES >> GO TO 5.
NO >> Repair or replace damaged parts.
5.CHECK TRANSFER SHIFT RELAY GROUND CIRCUIT
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Remove transfer shift high relay and transfer shift low relay.
3. Check continuity between transfer shift high relay harness con- nector E46 (A) terminals 2, 4, transfer shift low relay harness
connector E47 (B) terminals 2, 4 and ground.
Also check harness for short to ground and short to power.
Are the inspection results normal?
YES >> GO TO 6.
NO >> Repair open circuit or short to ground or short to power in harness or connectors.
6.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to DLN-81, "
Reference Value".
Are the inspection results normal?
YES-1 >> With CONSULT-III: GO TO 7.
YES-2 >> Without CONSULT-III: GO TO 8.
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.
Connector Terminal Voltage (Approx.)
A: E46 5 - Ground
Battery voltage
B: E47 5 - Ground
WDIA0311E
Continuity should exist.
WDIA0315E
Continuity should exist.
WDIA0312E
Revision: April 20092010 QX56

DLN-52
< COMPONENT DIAGNOSIS >[ATX14B]
P1819 TRANSFER CONTROL DEVICE
7.PERFORM SELF-DIAGNOSIS (WITH CONSULT-III)
With CONSULT-III
1. Turn ignition switch ON. (Do not start engine.)
2. Select SELF-DIAG RESULTS mode for ALL MODE AWD/4WD with CONSULT-III.
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
DLN-130, "Removal and Installation".
NO >> Inspection End.
8.PERFORM SELF-DIAGNOSIS (WITHOUT CONSULT-III)
Without CONSULT-III1. Perform the self-diagnosis and then erase self-diagnostic results. Refer to DLN-18, "CONSULT-III Func-
tion (ALL MODE AWD/4WD)".
2. Perform the self-diagnosis again.
Do the self-diagnostic results indicate transfer control device?
YES >> Replace transfer control unit.
NO >> Inspection End.
Revision: April 20092010 QX56

P1820 ENGINE SPEED SIGNALDLN-53
< COMPONENT DIAGNOSIS > [ATX14B]
C
EF
G H
I
J
K L
M A
B
DLN
N
O P
P1820 ENGINE SPEED SIGNAL
DescriptionINFOID:0000000005148814
The ECM transmits the engine speed signal via CAN comm unication to the transfer control unit. DTC P1820
will set when either of the following occur:
• Malfunction is detected in engine speed signal that is output from the ECM.
• Improper signal is input while driving.
DTC LogicINFOID:0000000005148815
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Perform self-diagnosis.
Is DTC P1820 detected?
YES >> Perform diagnosis procedure. Refer to DLN-53, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000005148816
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 the 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
Drive the vehicle and then perform self-diagnosis.
Are the inspection results normal?
YES >> Inspection End.
NO >> Perform self-diagnosis with ECM again.
DTC CONSULT-III Diagnostic item is detected when... Reference
[P1820] ENGINE SPEED SIG • Malfunction is detected in engine
speed signal that is output from ECM
through CAN communication.
• Improper signal is input while driving. Refer to DLN-53
.
Revision: April 20092010 QX56

DLN-54
< COMPONENT DIAGNOSIS >[ATX14B]
P1822 CLUTCH PRESSURE SOLENOID
P1822 CLUTCH PRESSURE SOLENOID
DescriptionINFOID:0000000005148817
Proper voltage is not applied to the clutch pres
sure solenoid valve due to open or short circuit.
DTC LogicINFOID:0000000005148818
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Perform self-diagnosis.
Is DTC P1822 displayed?
YES >> Perform diagnosis procedure. Refer to DLN-54, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000005148819
Regarding Wiring Diagram information, refer to DLN-89, "Wiring Diagram - ALL-MODE 4WD SYSTEM -".
1.CHECK CLUTCH PRESSURE SIGNAL
With CONSULT-III1. Start engine.
2. Select DATA MONITOR mode for ALL MODE AWD/4WD with CONSULT-III.
3. Read out the value of DUTY SOLENOID.
Without CONSULT-III1. Start engine.
2. Check voltage between transfer control unit harness connector
terminal and ground.
DTC CONSULT-III Diagnostic item is detected when... Reference
[P1822] DUTY SOLENOID Proper voltage is not applied to clutch
pressure solenoid valve due to open or
short circuit.Refer to
DLN-54
.
Condition Display value
• Vehicle stopped
• Engine running
• A/T selector lever N position
• Brake pedal depressed 4WD shift switch: 2WD
4%
4WD shift switch: AUTO 96 - 4%
4WD shift switch: 4H or
4LO 4%
SDIA2719E
Revision: April 20092010 QX56

P1822 CLUTCH PRESSURE SOLENOIDDLN-55
< COMPONENT DIAGNOSIS > [ATX14B]
C
EF
G H
I
J
K L
M A
B
DLN
N
O P
Are the inspection results normal?
YES >> GO TO 7.
NO >> GO TO 2.
2.CHECK HARNESS BETWEEN TRANSFER CONT ROL UNIT AND CLUTCH PRESSURE SOLENOID
VA LV E
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector, tr ansfer terminal cord assembly harness connector
and transfer dropping resistor.
3. Check continuity between transfer control unit harness connec- tor E142 terminal 19 and transfer terminal cord assembly har-
ness connector F56 terminal 6.
4. Check continuity between transfer dropping resistor harness connector E135 terminal 2 and transfer terminal cord assembly
harness connector F56 terminal 6.
Also check harness for short to ground and short to power.
Are the inspection results normal?
YES >> GO TO 3.
NO >> Repair or replace damaged parts.
3.CHECK HARNESS BETWEEN TRAN SFER CONTROL UNIT AND TRANSFER DROPPING RESISTOR
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connecto r and transfer dropping resistor harness connector.
Connector TerminalConditionVoltage
(Approx.)
E142 10 -
Ground • Vehicle stopped
• Engine running
• A/T selector lever
N position
• Brake pedal de- pressed 4WD shift switch:
AUTO
4 - 14V
4WD shift switch:
2WD, 4H or 4LO Less than
1V
19 -
Ground • Vehicle stopped
• Engine running
• A/T selector lever
N position
• Brake pedal de-
pressed 4WD shift switch:
AUTO
1.5 - 3V
4WD shift switch:
2WD, 4H or 4LO Less than
1V
Continuity should exist.
SDIA2720E
Continuity should exist.
SDIA2721E
Revision: April 20092010 QX56