2009 INFINITI QX56 check engine

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:0000000003772126
Proper voltage is not applied to the 2-4WD so lenoid valve due to an open or short circuit.
DTC LogicINFOID:0000000003772127
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:0000000003772128
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: December 20092009 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 Condition Voltage
(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 Condition
Voltage (Ap-
prox.)
M141 4 - ground 4WD shift switch: AUTO, 4H or 4LO Battery voltage
4WD shift switch: 2WD 0V
SDIA2729E
Revision: December 20092009 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:0000000003772130
Motor does not operate properly due to open or short ci rcuit in transfer motor or transfer motor relay.
DTC LogicINFOID:0000000003772131
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:0000000003772132
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: December 20092009 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 Condition Voltage (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: December 20092009 QX56

P1824 TRANSFER MOTORDLN-63
< COMPONENT DIAGNOSIS > [ATX14B]
C
EF
G H
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M A
B
DLN
N
O P
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 3 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 Condition Voltage (Approx.)
Connector Terminal Voltage (Approx.)
E153 2 - Ground 0V
E154 5 - Ground Battery voltage
WDIA0169E
Connector Terminal Voltage (Approx.)E153 2 - Ground Battery voltage
E154 5 - Ground
WDIA0170E
Revision: December 20092009 QX56

P1826 TRANSFER FLUID TEMPERATURE
DLN-67
< COMPONENT DIAGNOSIS > [ATX14B]
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G H
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M A
B
DLN
N
O P
P1826 TRANSFER FLUID TEMPERATURE
DescriptionINFOID:0000000003772134
Signal voltage from the transfer fluid temperature sens or is abnormally high (Transfer fluid temperature is
abnormally low) while driving.
DTC LogicINFOID:0000000003772135
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:0000000003772136
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-
DTC CONSULT-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 Condition Data
(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: December 20092009 QX56

DLN-70
< COMPONENT DIAGNOSIS >[ATX14B]
P1827 CLUTCH PRESSURE SWITCH
P1827 CLUTCH PRESSURE SWITCH
DescriptionINFOID:0000000003772138
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:0000000003772139
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:0000000003772140
1.CHECK CLUTCH PRESSURE SWITCH SIGNAL
With CONSULT-III1. Start engine.
2. Select DATA MONITOR mode for A LL 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 Condition Voltage
(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: December 20092009 QX56

P1828 LINE PRESSURE SWITCHDLN-73
< COMPONENT DIAGNOSIS > [ATX14B]
C
EF
G H
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J
K L
M A
B
DLN
N
O P
P1828 LINE PRESSURE SWITCH
DescriptionINFOID:0000000003772142
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:0000000003772143
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:0000000003772144
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: December 20092009 QX56