2008 INFINITI QX56 Stop

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
I
J
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
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 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

DLN-80
< ECU DIAGNOSIS >[ATX14B]
TRANSFER CONTROL UNIT
ECU DIAGNOSIS
TRANSFER CONTROL UNIT
Reference ValueINFOID:0000000001737179
VALUE ON THE DIAGNOSIS TOOL
CONSULT-III data monitor item
Monitored item [Unit]
Content ConditionDisplay value
VHCL/S SEN·FR [km/h]
or [mph] Wheel speed (Front
wheel) Vehicle stopped
0 km/h (0 mph)
Vehicle running
CAUTION:
Check air pressure of tire under standard condition. Approximately
equal to the indica-
tion on speedome-
ter (Inside of
±
10%)
VHCL/S SEN·RR [km/h]
or [mph] Wheel speed (Rear
wheel) Vehicle stopped
0 km/h (0 mph)
Vehicle running
CAUTION:
Check air pressure of tire under standard condition. Approximately
equal to the indica-
tion on speedome-
ter (Inside of
±
10%)
ENGINE SPEED [rpm] Engine speed Engine stopped
(Engine speed: Less than 400 rpm)
0 rpm
Engine running
(Engine speed: 400 rpm or more) Approximately
equal to the indica-
tion on tachometer
THRTL POS SEN [V] Accelerator
pedal posi-
tion (APP) sensor signal
voltage Accelerator pedal: Released
Approx. 0.5V
Accelerator pedal: Fully depressed Approx. 4.0V
FLUID TEMP SE [V] Transfer fluid tempera-
ture signal voltage Transfer fluid temperature approx. 20 - 80
°C (68 - 176 °F) Approx. 1.1 - 0.3V
BATTERY VOLT [V] Power supply voltage for
transfer control unit Ignition switch: ON
Battery voltage
2WD SWITCH [ON/OFF] Input condition from 4WD
shift switch 4WD shift switch: 2WD
ON
4WD shift switch: AUTO, 4H or 4LO OFF
AUTO SWITCH [ON/
OFF] Input condition from 4WD
shift switch 4WD shift switch: AUTO
ON
4WD shift switch: 2WD, 4H or 4LO OFF
LOCK SWITCH [ON/
OFF] Input condition from 4WD
shift switch 4WD shift switch: 4H
ON
4WD shift switch: 2WD, AUTO or 4LO OFF
4L SWITCH [ON/OFF] Input condition from 4WD
shift switch 4WD shift switch: 4LO
ON
4WD shift switch: 2WD, AUTO or 4H OFF
N POSI SW TF [ON/
OFF] Condition of neutral-4LO
switch • Vehicle stopped
• Engine running
• A/T selector lever N posi-
tion
• Brake pedal depressed 4WD shift switch: 2WD,
AUTO or 4H
OFF
4WD shift switch: 4H to
4LO (While actuator mo-
tor is operating.) OFF
→ON
4WD shift switch: 4LO to
4H (While actuator motor
is operating.) ON
→OFF
4WD shift switch: 4LO ON
Revision: March 2010 2008 QX56

TRANSFER CONTROL UNITDLN-81
< ECU DIAGNOSIS > [ATX14B]
C
EF
G H
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K L
M A
B
DLN
N
O P
ATP SWITCH [ON/OFF] Condition of ATP switch • Vehicle stopped
• Engine running
• A/T selector lever N posi-
tion
• Brake pedal depressed 4WD shift switch
: 4H to 4LO or 4LO to 4H
(While actuator motor is
operating.)
ON
Except the above OFF
WAIT DETCT SW [ON/
OFF] Condition of wait detec-
tion switch • Vehicle stopped
• Engine running
• A/T selector lever N posi-
tion
• Brake pedal depressed 4WD shift switch: 2WD,
AUTO or 4H
OFF
4WD shift switch: 4H to
4LO (While actuator mo-
tor is operating.) OFF
→ON
4WD shift switch: 4LO to
4H (While actuator motor
is operating.) ON
→OFF
4WD shift switch: 4LO ON
LINE PRES SW [ON/
OFF] Condition of line pres-
sure switch • 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
CL PRES SW [ON / OFF] Condition of clutch pres-
sure switch • Vehicle stopped
• Engine running
• A/T selector lever D position
• 4WD shift switch: AUTO or 4H (Wait function is not op-
erating.) ON
• Vehicle stopped
• Engine running
• 4WD shift switch: 2WD (Wait function is not operating.) OFF
N POSI SW AT [ON/
OFF] Input condition from A/T
transmission range
switch • Vehicle stopped
• Engine running
• Brake pedal depressed A/T selector lever posi-
tion: N
ON
Except the above OFF
R POSI SW AT [ON/
OFF] Input condition from A/T
transmission range
switch • Vehicle stopped
• Engine running
• Brake pedal depressed A/T selector lever posi-
tion: R
ON
Except the above OFF
P POSI SW AT [ON/OFF] Input condition from A/T
transmission range
switch • Vehicle stopped
• Engine running
• Brake pedal depressed A/T selector lever posi-
tion: P
ON
Except the above OFF
ABS OPER SW [ON/
OFF] Condition of ABS operat-
ing ABS is operating.
ON
ABS is not operating. OFF
VDC OPE R
SW [O

N/
OFF] Condition of VDC operat-
ing VDC is operating.
ON
VDC is not operating. OFF
TCS OPER SW [ON/
OFF] Condition of TCS operat-
ing TCS is operating.
ON
TCS is not operating. OFF
THROTTLE POSI [0.0/8] Condition of throttle
opening When depressing accelerator pedal
(Value rises gradually in response to throttle position.)
0.0/8 - 8.0/8
4WD MODE [AUTO/
LOCK/2WD/4L] Control status of 4WD
(Output condition of 4WD
shift indicator lamp and
4LO indicator lamp) • Vehicle stopped
• Engine running
• A/T selector lever N posi-
tion
• Brake pedal depressed 4WD shift switch: 2WD
2WD
4WD shift switch: AUTO AUTO
4WD shift switch: 4H LOCK
4WD shift switch: 4LO 4L
Monitored item [Unit]
Content ConditionDisplay value
Revision: March 2010 2008 QX56

DLN-82
< ECU DIAGNOSIS >[ATX14B]
TRANSFER CONTROL UNIT
VHCL/S COMP [km/h] or
[mph]Vehicle speed Vehicle stopped
0 km/h (0 mph)
Vehicle running
CAUTION:
Check air pressure of tire under standard condition. Approximately
equal to the indica-
tion on speedome-
ter (Inside of
±
10%)
COMP CL TORQ [kgm] Condition of control
torque • Vehicle stopped
• Engine running
• A/T selector lever N posi-
tion
• Brake pedal depressed 4WD shift switch: 2WD 0 kg-m
4WD shift switch: AUTO
39 - 1,353 N·m
(4 - 138 kg-m, 29 - 998 ft-lb)
4WD shift switch: 4H or
4LO 1,353 N·m
(138 kg-m, 998 ft-
lb)
DUTY SOLENOID [%] Condition of clutch pres-
sure solenoid • Vehicle stopped
• Engine running
• A/T selector lever N posi-
tion
• Brake pedal depressed 4WD shift switch: 2WD
4%
4WD shift switch: AUTO 96 - 4%
4WD shift switch: 4H or
4LO 4%
2-4WD SOL [ON/OFF] Condition of 2-4WD shift
solenoid valve • Vehicle stopped
• Engine running
• A/T selector lever N posi-
tion
• Brake pedal depressed 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 operat-
ing.) OFF
4WD shift switch: 4H
(Wait function is operat-
ing.) OFF
2-4WD SOL MON [ON/
OFF] Check signal for transfer
control unit signal output • Vehicle stopped
• Engine running
• A/T selector lever N posi-
tion
• Brake pedal depressed 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 operat-
ing.) OFF
4WD shift switch: 4H
(Wait function is operat-
ing.) OFF
MOTOR RELAY [ON/
OFF] Condition of transfer mo-
tor relay • Accelerator pedal de-
pressed
• Vehicle stopped
• Engine running
• Brake pedal depressed 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 se-
lector lever P or N posi-
tion) ON
4WD shift switch: 4H (A/T
selector lever P position) OFF
(ON fo r appro
x
. 2
sec. after shifting to P.)
4WD shift switch: 4H (Ex-
cept for A/T selector lever
P position) ON
Monitored item [Unit]
Content ConditionDisplay value
Revision: March 2010 2008 QX56

TRANSFER CONTROL UNITDLN-83
< ECU DIAGNOSIS > [ATX14B]
C
EF
G H
I
J
K L
M A
B
DLN
N
O P
MOTOR RELAY MON
[ON/OFF] Check signal for transfer
control unit signal output • Accelerator pedal de-
pressed
• Vehicle stopped
• Engine running
• Brake pedal depressed 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 se-
lector lever P or N posi-
tion) ON
4WD shift switch: 4H (A/T
selector lever P position) OFF
(ON for approx. 2
sec. after shifting to P.)
4WD shift switch: 4H (Ex-
cept for A/T selector lever
P position) ON
4WD FAIL LAMP [ON/
OFF] Condition of 4WD warn-
ing lamp 4WD warning lamp: ON
ON
4WD warning lamp: OFF OFF
2WD IND [ON/OFF] Condition of 4WD shift in-
dicator lamp (2WD indi-
cator lamp) 2WD indicator lamp of 4WD shift indicator lamp: OFF
OFF
2WD indicator lamp of 4WD shift indicator lamp: ON ON
AUTO IND [ON/OFF] Condition of 4WD shift in-
dicator lamp (AUTO indi-
cator lamp) AUTO indicator lamp of 4WD shift indicator lamp: OFF
OFF
AUTO indicator lamp of 4WD shift indicator lamp: ON ON
LOCK IND [ON/OFF] Condition of 4WD shift in-
dicator lamp
(Lock indi-
cator lamp) Lock indicator lamp of 4WD shift indicator lamp: OFF
OFF
Lock indicator lamp of 4WD shift indicator lamp: ON ON
4L IND [ON/OFF] Condition of 4LO indica-
tor lamp condition 4LO indicator lamp: OFF
OFF
4LO indicator lamp: ON ON
ATP IND [ON/OFF] Condition of ATP indica-
tor lamp ATP indicator lamp: ON
ON
ATP indicator lamp: OFF OFF
SHIFT POS SW1 [ON/
OFF] Condition of actuator po-
sition switch 1
(Low) • Vehicle stopped
• Engine running
• A/T selector lever N posi-
tion
• Brake pedal depressed 4WD shift switch: 4LO
ON
4WD shift switch: 2WD,
AUTO or 4H OFF
SHIFT POS SW2 [ON/
OFF] Condition of actuator po-
sition switch 2
(High) • Vehicle stopped
• Engine running
• A/T selector lever N posi-
tion
• Brake pedal depressed 4WD shift switch: 4H,
AUTO or 2WD
ON
4WD shift switch: 4LO OFF
SHIFT ACT1 [ON/OFF] Output condition to actu-
ator motor (High) • Vehicle stopped
• Engine running
• A/T selector lever N posi-
tion
• Brake pedal depressed 4WD shift switch: 4H to
4LO (Wait function is op-
era
ti
ng.

) ON
Except the above OFF
SHIFT AC MON1 [ON/
OFF] Check signal for transfer
control unit signal output • Vehicle stopped
• Engine running
• A/T selector lever N posi-
tion
• Brake pedal depressed 4WD shift switch: 4H to
4LO (Wait function is op-
erating.)
ON
Except the above OFF
SHIFT ACT2 [ON/OFF] Output condition to actu-
ator motor (Low) • Vehicle stopped
• Engine running
• A/T selector lever N posi-
tion
• Brake pedal depressed 4WD shift switch: 4LO to
4H (Wait function is oper-
ating.)
ON
Except the above OFF
Monitored item [Unit]
Content ConditionDisplay value
Revision: March 2010 2008 QX56