engine INFINITI QX56 2008 Factory Service Manual

DLN-52
< COMPONENT DIAGNOSIS >[ATX14B]
P1820 ENGINE SPEED SIGNAL
P1820 ENGINE SPEED SIGNAL
DescriptionINFOID:0000000001737140
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:0000000001737141
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-52, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000001737142
1.CHECK DTC WITH ECM
Perform self-diagnosis with ECM. Refer to EC-63, "
CONSULT-III Function (ENGINE)".
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-80, "
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
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-52
.
Revision: March 2010 2008 QX56

P1822 CLUTCH PRESSURE SOLENOIDDLN-53
< COMPONENT DIAGNOSIS > [ATX14B]
C
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B
DLN
N
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P1822 CLUTCH PRESSURE SOLENOID
DescriptionINFOID:0000000001737143
Proper voltage is not applied to the clutch pressure solenoid valve due to open or short circuit.
DTC LogicINFOID:0000000001737144
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-53, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000001737145
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-53
.
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%
Connector Terminal
ConditionVoltage
(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
SDIA2719E
Revision: March 2010
2008 QX56

P1823 2-4 SOLENOIDDLN-57
< COMPONENT DIAGNOSIS > [ATX14B]
C
EF
G H
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M A
B
DLN
N
O P
P1823 2-4 SOLENOID
DescriptionINFOID:0000000001737147
Proper voltage is not applied to the 2-4WD solenoid valve due to an open or short circuit.
DTC LogicINFOID:0000000001737148
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Perform self-diagnosis.
Is DTC P1823 displayed?
YES >> Perform diagnosis procedure. Refer to DLN-57, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000001737149
1.CHECK 4WD SHIF T SWITCH SYSTEM
Perform self-diagnosis. Refer to DLN-18, "
CONSULT-III Function (ALL MODE AWD/4WD)".
Is the 4WD MOD SW [P1814] (with CO NSULT-III) or Flickering pattern: 16 (without CONSULT-III) detected?
YES >> Perform trouble diagnosis for 4WD shift switch. Refer to DLN-31, "Diagnosis Procedure".
NO >> GO TO 2.
2.CHECK 2-4WD SHIFT SOLENOID 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 2-4WD SOL and 2-4WD SOL MON.
DTC CONSULT-III Diagnostic item is detected when... Reference
[P1823] 2-4WD SOLENOID Proper voltage is not applied to 2-4WD
solenoid valve due to open or short cir-
cuit.Refer to DLN-57
.
Monitored
item Condition Display
value
2-4WD SOL • Vehicle stopped
• Engine running
• A/T selector lever N
position
• Brake pedal de- pressed 4WD shift switch: 2WD OFF
4WD shift switch: AUTO
ON
4WD shift switch: 4H
4WD shift switch: 4LO
4WD shift switch: AUTO
(Wait function is operating.) OFF
4WD shift switch: 4H (Wait
function is operating.) OFF
Revision: March 2010
2008 QX56

DLN-58
< COMPONENT DIAGNOSIS >[ATX14B]
P1823 2-4 SOLENOID

Without CONSULT-III
1. Start engine.
2. Check voltage between transfer control unit harness connector
terminal and ground.
Are the inspection results normal?
YES >> GO TO 7.
NO >> GO TO 3.
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.
Are the inspection results normal?
YES >> GO TO 4.
NO >> Check 4WD shift switch. Refer to DLN-33, "
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.
2-4WD SOL
MON • Vehicle stopped
• Engine running
• A/T selector lever N
position
• Brake pedal de- pressed 4WD shift switch: 2WD OFF
4WD shift switch: AUTO
ON
4WD shift switch: 4H
4WD shift switch: 4LO
4WD shift switch: AUTO
(Wait function is operating.) OFF
4WD shift switch: 4H (Wait
function is operating.) OFF
Monitored
item Condition Display
value
Connector Terminal ConditionVoltage
(Approx.)
E142 1 -
Ground • Vehicle stopped
• Engine running
• A/T selector lever
N position
• Brake pedal de-
pressed 4WD shift switch: 2WD 0V
4WD shift switch: AU-
TO, 4H or 4LO
Battery
voltage
SDIA2728E
Connector Terminal
ConditionVoltage (Ap-
prox.)
M141 4 - ground 4WD shift switch: AUTO, 4H or 4LO Battery voltage
4WD shift switch: 2WD
0V
SDIA2729E
Revision: March 2010 2008 QX56

P1824 TRANSFER MOTORDLN-61
< COMPONENT DIAGNOSIS > [ATX14B]
C
EF
G H
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K L
M A
B
DLN
N
O P
P1824 TRANSFER MOTOR
DescriptionINFOID:0000000001737151
Motor does not operate properly due to open or short circuit in transfer motor or transfer motor relay.
DTC LogicINFOID:0000000001737152
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Perform self-diagnosis.
Is DTC P1824 displayed?
YES >> Perform diagnosis procedure. Refer to DLN-61, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000001737153
1.CHECK TRANSFER MOTOR RELAY 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 MOTOR RELAY and MOTOR RELAY MON.
DTC CONSULT-III Diagnostic item is detected when... Reference
[P1824] MOTOR RELAY Motor does not operate properly due to
open or short circuit in transfer motor or
transfer motor relay.Refer to DLN-61
.
Monitored
item Condition Display value
(Approx.)
MOTOR
RELAY • Accelerator ped-
al depressed
• Vehicle stopped
• Engine running
• Brake pedal de- pressed 4WD 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 se-
lector 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
Revision: March 2010
2008 QX56

DLN-62
< COMPONENT DIAGNOSIS >[ATX14B]
P1824 TRANSFER MOTOR

Without CONSULT-III
1. Start engine.
2. Check voltage between transfer control unit harness connector
terminal and ground.
MOTOR
RELAY
MON • Accelerator ped-
al depressed
• Vehicle stopped
• Engine running
• Brake pedal de- pressed 4WD 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 se-
lector 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
Monitored
item Condition Display value
(Approx.)
Connector Terminal ConditionVoltage (Approx.)
E142 14 -
Ground • Accelera-
tor pedal
depressed
• Vehicle
stopped
•Engine running
•Brake pedal de-
pressed 4WD 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 (Ex-
cept 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 se-
lector lever P posi-
tion) 0V
SDIA2735E
Revision: March 2010
2008 QX56

P1824 TRANSFER MOTORDLN-63
< COMPONENT DIAGNOSIS > [ATX14B]
C
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G H
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M A
B
DLN
N
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Are the inspection results normal?
YES >> GO TO 7.
NO >> GO TO 2.
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.
Are the inspection results normal?
YES >> GO TO 3.
NO >> Check the following. If any items are damaged, repair or replace damaged parts.
• 20A fuse (No. 58 located in the fuse and relay box).
• 10A fuse (No. 26 located in the fuse and fusible link box).
• Harness for short or open between battery and transfer motor relay harness connector E154 ter- minal 5.
• Harness for short or open between transfer shut off relay harness connector E69 terminal 5 and transfer motor relay harness connector E153 terminal 2.
E143 41 -
Ground • Accelera-
tor pedal
depressed
• Vehicle
stopped
•Engine running
•Brake pedal de-
pressed 4WD shift switch:
2WD
0V
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 (Ex-
cept 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 se-
lector lever P posi-
tion) Battery voltage
Connector Terminal
ConditionVoltage (Approx.)
Connector Terminal Voltage (Approx.)
E153 2 - Ground 0V
E154 5 - Ground Battery voltage
WDIA0169E
ConnectorTerminal Voltage (Approx.)
E153 2 - Ground
Battery voltage
E154 5 - Ground
WDIA0170E
Revision: March 2010 2008 QX56

P1826 TRANSFER FLUID TEMPERATUREDLN-67
< COMPONENT DIAGNOSIS > [ATX14B]
C
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G H
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M A
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DLN
N
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P1826 TRANSFER FLUID TEMPERATURE
DescriptionINFOID:0000000001737155
Signal voltage from the transfer fluid temperature sens or is abnormally high (Transfer fluid temperature is
abnormally low) while driving.
DTC LogicINFOID:0000000001737156
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Perform self-diagnosis.
Is DTC P1826 displayed?
YES >> Perform diagnosis procedure. Refer to DLN-67, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000001737157
1.CHECK TRANSFER FLUID TE MPERATURE SENSOR 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 FLUID TEMP SE.
Without CONSULT-III
1. Start engine.
2. Check voltage between transfer control unit harness connector
terminals and ground.
Are inspection results normal?
YES >> GO TO 4.
NO >> GO TO 2.
2.CHECK HARNESS BETWEEN TRANSF ER CONTROL UNIT AND TRANSFER TERMINAL CORD AS-
DTCCONSULT-III Diagnostic item is detected when... Reference
[P1826] OIL TEMP SEN Signal voltage from transfer fluid temper-
ature sensor is abnormally high (Trans-
fer fluid temperature is abnormally low)
while driving.Refer to DLN-67
.
Condition
Display value
(Approx.)
Transfer fluid temperature approx. 20 - 80 °C (68 - 176° F) 1.1 - 0.3V
Connector Terminal ConditionData
(Approx.)
E143 28 -
Ground Always
0V
31 -
Ground Ignition switch:
ON Transfer fluid temperature
approx. 20
°C (68 °F) 1.1V
Transfer fluid temperature
approx. 80 °C (176 °F) 0.3V
SDIA2742E
Revision: March 2010
2008 QX56

DLN-70
< COMPONENT DIAGNOSIS >[ATX14B]
P1827 CLUTCH PRESSURE SWITCH
P1827 CLUTCH PRESSURE SWITCH
DescriptionINFOID:0000000001737159
Improper signal from the clutch pressure switch is i
nput due to open or short circuit. Also, a malfunction may
have occured in clutch pressure switch or hydraulic circuit.
DTC LogicINFOID:0000000001737160
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-70, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000001737161
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.
2. Check voltage between transfer control unit harness connector
terminals and ground.
Are inspection results normal?
DTC CONSULT-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-70
.
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
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
Revision: March 2010
2008 QX56

P1828 LINE PRESSURE SWITCHDLN-73
< COMPONENT DIAGNOSIS > [ATX14B]
C
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G H
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M A
B
DLN
N
O P
P1828 LINE PRESSURE SWITCH
DescriptionINFOID:0000000001737163
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:0000000001737164
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-73, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000001737165
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.
2. Check voltage between transfer control unit harness connector
terminals and ground.
DTC CONSULT-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-73
.
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
SDIA2751E
Revision: March 2010
2008 QX56