2011 INFINITI QX56 engine

DLN-2
Work Procedure ......................................................47
CONFIGURATION (TRANSFER CONTROL
UNIT) ..................................................................
48
Description ........................................................... ...48
Work Procedure ......................................................48
DTC/CIRCUIT DIAGNOSIS ...................... ...51
P1802, P1803, P1804, P1809 TRANSFER
CONTROL UNIT ............................................. ...
51
DTC Logic ............................................................ ...51
Diagnosis Procedure ..............................................51
P1807 OUT PUT SHAFT SPEED SENSOR ......52
DTC Logic ............................................................ ...52
Diagnosis Procedure ..............................................52
P1808 WHEEL SPEED SENSOR ......................53
DTC Logic ............................................................ ...53
Diagnosis Procedure ..............................................53
P180C SENSOR POWER SUPPLY (5V) ..........54
Description ........................................................... ...54
DTC Logic ...............................................................54
Diagnosis Procedure ..............................................54
P180D TRANSFER ROTARY POSITION
SENSOR ............................................................
57
DTC Logic ............................................................ ...57
Diagnosis Procedure ..............................................57
P180E SENSOR POWER SUPPLY (8V) ...........59
Description ........................................................... ...59
DTC Logic ...............................................................59
Diagnosis Procedure ..............................................59
P180F TRANSFER INTERNAL SPEED SEN-
SOR ....................................................................
61
DTC Logic ............................................................ ...61
Diagnosis Procedure ..............................................61
P1811 POWER SUPPLY CIRCUIT FOR
TRANSFER CONTROL UNIT ............................
64
Description ........................................................... ...64
DTC Logic ...............................................................64
Diagnosis Procedure ..............................................64
P1813 4WD MODE SWITCH .............................67
DTC Logic ............................................................ ...67
Diagnosis Procedure ..............................................67
Component Inspection ............................................68
P1816 PARKING/NEUTRAL POSITION
SWITCH .............................................................
69
DTC Logic ............................................................ ...69
Diagnosis Procedure ..............................................69
P1817 TRANSFER MOTOR ..............................70
DTC Logic ............................................................ ...70
Diagnosis Procedure ..............................................70
Component Inspection ......................................... ...71
P181A TRANSFER MOTOR TEMPERATURE
SENSOR ............................................................
72
DTC Logic ............................................................ ...72
Diagnosis Procedure ...............................................72
Component Inspection ............................................73
P181B INCOMPLETE SELFSHUT ....................74
DTC Logic ............................................................ ...74
Diagnosis Procedure ...............................................74
P181C TRANSFER MOTOR POWER SUP-
PLY ....................................................................
76
Description ........................................................... ...76
DTC Logic ...............................................................76
Diagnosis Procedure ...............................................76
P181E STEERING ANGLE SENSOR ...............77
DTC Logic ............................................................ ...77
Diagnosis Procedure ...............................................77
P181F INCOMPLETE CALIBRATION ..............78
DTC Logic ............................................................ ...78
Diagnosis Procedure ...............................................78
P1820 ENGINE SPEED SIGNAL ......................79
DTC Logic ............................................................ ...79
Diagnosis Procedure ...............................................79
P1826 TRANSFER FLUID TEMPERATURE ....80
DTC Logic ............................................................ ...80
Diagnosis Procedure ...............................................80
Component Inspection ............................................81
P1829 ACCELERATOR PEDAL POSITION
SENSOR ............................................................
82
DTC Logic ............................................................ ...82
Diagnosis Procedure ...............................................82
P182A TRANSFER HI-LO POSITION SEN-
SOR ...................................................................
83
DTC Logic ............................................................ ...83
Diagnosis Procedure ...............................................83
P182B TRANSFER LOCK POSITION SEN-
SOR ...................................................................
85
DTC Logic ............................................................ ...85
Diagnosis Procedure ...............................................85
P1830 ABS OPERATION SIGNAL ...................88
DTC Logic ............................................................ ...88
Diagnosis Procedure ...............................................88
P1831 VDC OPERATION SIGNAL ...................89
DTC Logic ............................................................ ...89
Diagnosis Procedure ...............................................89
P1832 TCS OPERATION SIGNAL ....................90
DTC Logic ............................................................ ...90
Diagnosis Procedure ...............................................90
Revision: 2010 May2011 QX56

DLN-6
< PRECAUTION >[TRANSFER: ATX90A]
PRECAUTIONS
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint S
ystem (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000006222209
The Supplemental Restraint System such as “A IR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severi ty of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and w hether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the “SRS AIR BAG” and “SEAT BELT” of this
Service Manual.
WARNING:
• To avoid rendering the SRS inopera tive, which could increase the risk of personal injury or death in
the event of a collision that would result in air bag inflation, all maintenance must be performed by
an authorized NISS AN/INFINITI dealer.
 Improper maintenance, including in correct removal and installation of the SRS, can lead to personal
injury caused by unintent ional activation of the system. For re moval of Spiral Cable and Air Bag
Module, see the “SRS AIR BAG”.
 Do not use electrical test equipmen t on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identi fied by yellow and/or orange harnesses or har-
ness connectors.
PRECAUTIONS WHEN USING POWER TOOLS (AIR OR ELECTRIC) AND HAMMERS
WARNING:
 When working near the Air Bag Diagnosis Sensor Unit or other Air Bag System sensors with the ignition ON or engine running, DO NOT use air or electric power tools or strike near the sensor(s)
with a hammer. Heavy vibration could activate the sensor(s) and deploy the air bag(s), possibly
causing serious injury.
 When using air or electric power tools or hammers , always switch the ignition OFF, disconnect the
battery, and wait at least 3 minu tes before performing any service.
Precaution Necessary for Steering W heel Rotation after Battery Disconnect
INFOID:0000000006222210
NOTE:
 Before removing and installing any control units, first tu rn the push-button ignition switch to the LOCK posi-
tion, then disconnect bot h battery cables.
 After finishing work, confirm that all control unit connectors are connected properly, then re-connect both
battery cables.
 Always use CONSULT-III to perform self-diagnosis as a part of each function inspection after finishing work.
If a DTC is detected, perform trouble diagnos is according to self-diagnosis results.
For vehicle with steering lock unit, if the battery is disconnected or discharged, the steering wheel will lock and
cannot be turned.
If turning the steering wheel is required with the bat tery disconnected or discharged, follow the operation pro-
cedure below before starting the repair operation.
OPERATION PROCEDURE
1. Connect both battery cables. NOTE:
Supply power using jumper cables if battery is discharged.
2. Turn the push-button ignition switch to ACC position. (At this time, the steering lock will be released.)
3. Disconnect both battery cables. The steering lock wi ll remain released with both battery cables discon-
nected and the steering wheel can be turned.
4. Perform the necessary repair operation.
Revision: 2010 May2011 QX56

COMPONENT PARTSDLN-11
< SYSTEM DESCRIPTION > [TRANSFER: ATX90A]
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Component DescriptionINFOID:0000000006222215
Transfer Control UnitINFOID:0000000006222216
 Transfer control unit operates transfer control act uator, 4WD warning lamp and 4WD mode indicator lamp
according to input signal from 4WD shift switch and each sensor and control unit.
 When 4WD system is malfunctioning, 4WD warning la mp turns ON and fail-safe status activates.
 When protection is necessary, 4WD warning la mp blinks and protection status activates.
Transfer Control ActuatorINFOID:0000000006222217
Transfer control actuator integrates transfer motor, transfer internal position sensor, and transfer motor tem-
perature sensor, and switches 4WD mode (AUTO ⇔4H ⇔4L).
TRANSFER MOTOR
Transfer motor operates according to signal from transfer control unit and switches 4WD mode
(AUTO ⇔4H ⇔4L). It also performs front and rear distri bution of traction force during AUTO mode.
TRANSFER INTERNAL SPEED SENSOR
Transfer internal speed sensor detects rotation status of transfer motor and transmits signal to transfer control
unit.
TRANSFER MOTOR TEMPERATURE SENSOR
 Transfer motor temperature sensor m easures temperature of transfer motor.
Component parts Reference/Function
Transfer control unit DLN-11, "
Transfer Control Unit"
Transfer control actua-
torTransfer motor
DLN-11, "
Transfer Control Actuator"
Transfer internal speed
sensorDLN-11, "Transfer Control Actuator"
Transfer motor temper-
ature sensor
DLN-11, "Transfer Control Actuator"
Transfer Hi-Lo position sensor
DLN-12, "Transfer Hi-Lo Position Sensor"
Transfer rotary position sensorDLN-12, "Transfer Rotary Position Sensor"
Transfer lock position sensorDLN-12, "Transfer Lock Position Sensor"
Transfer fluid temperature sensorDLN-12, "Transfer Fluid Temperature Sensor"
4WD mode switchDLN-18, "4WD SYSTEM : System Description"
4WD indicator lampDLN-18, "4WD SYSTEM : System Description"
4WD warning lampDLN-18, "4WD SYSTEM : System Description"
AT P w a r n i n g l a m pDLN-18, "4WD SYSTEM : System Description"
ABS actuator and electric unit (control unit)Transmits the following signals via CAN communication line to transfer control unit.
 Vehicle speed signal (ABS)
 Stop lamp switch signal (brake signal)
 ABS operation signal
 VDC operation signal
 TCS operation signal
Steering angle sensor Transmits the following signals via CAN communication line to transfer control unit.
 Steering angle sensor signal
ECM Transmits the following signals via CAN communication line to transfer control unit.
 Accelerator pedal position signal
 Engine speed signal
 Engine torque signal
TCM Transmits the following signals via CAN communication line to transfer control unit.
 Shift position signal
 Gear position signal
 Output shaft revolution signal
Revision: 2010 May2011 QX56

DLN-18
< SYSTEM DESCRIPTION >[TRANSFER: ATX90A]
SYSTEM
SYSTEM
4WD SYSTEM
4WD SYSTEM : System DescriptionINFOID:0000000006222224
 In AUTO mode, distribution of traction force is cont
rolled from 2WD status (0:100) to 4WD status (50:50)
according to signal from each sensor and switch.
 In accordance with fail-safe function, when system is malfunctioning, 4WD warning lamp on combination meter turns ON and 4WD control stops. For fail-safe function, refer to DLN-20, "
4WD SYSTEM : Fail-Safe".
 When a high load status continues for transfer assembly (transfer control actuator or transfer fluid), 4WD
control temporarily becomes 4H or 2WD status, according to protection function.
NOTE:
4WD system is not malfunctioning.
SYSTEM DIAGRAM
INPUT/OUTPUT SIGNAL
It transmits/receives each signal from the followi ng transfer control unit via CAN communication line.
JPDIE0272GB
Component parts Control signal
ABS actuator and electric unit (control unit) Transmits the following signals via CAN communication line to transfer control unit.
 Vehicle spee
d signal (ABS)
 Stop lamp switch signal (brake signal)
 ABS operation signal
 VDC operation signal
 TCS operation signal
ECM Transmits the following signals via CAN communication line to transfer control unit.
 Accelerator pedal position signal
 Engine speed signal
 Engine torque signal
Revision: 2010 May2011 QX56

SYSTEMDLN-19
< SYSTEM DESCRIPTION > [TRANSFER: ATX90A]
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4WD SHIFT SWITCH AND 4WD SHIFT INDICATOR LAMP
*1: Blinking 2 times/1 second
*2: “4HI” and “4LO” blink alternately.
CONDITION FOR TURN ON THE WARNING LAMP
TCM Transmits the following signals via CAN communication line to transfer control unit.
 Shift position signal
 Gear position signal
 Output shaft revolution signal
Steering angle sensor Transmits the following signals via CAN communication line to transfer control unit.
 Steering angle sensor signal
Combination meter Receives the following signals via CAN communication line from transfer control unit.
 4WD warning lamp signal
 ATP warning lamp signal
 4WD mode indicator signal
Component parts Control signal
4WD shift switch 4WD shift indicator lamp (in Information display) 4WD shift procedure
AUTO
1. Start the engine.
2. Turn the 4WD shift switch.
NOTE:
Mode can be switched between AU-
TO⇔4H while driving straight.
4H
↓↑
4WD status: 4H ⇔4L (Blinking)
*1*2
1. Start the engine.
2. Never drive the vehicle.
3. Shift A/T shift selector to N position.
4. Press and rotate 4WD shift switch
while depressing brake pedal.
CAUTION:
4WD mode does not switch when 4WD
shift switch is operated while the vehi-
cle is running or A/T shift selector is
shifted to any position other than neu-
tral.
4L
JPDIE0230ZZJPDIE0234ZZ
JPDIE0231ZZJPDIE0235ZZ
JPDIE0231ZZ
JPDIE0233ZZ
JPDIE0236ZZ
JPDIE0233ZZJPDIE0237ZZ
Revision: 2010 May2011 QX56

DLN-20
< SYSTEM DESCRIPTION >[TRANSFER: ATX90A]
SYSTEM
4WD Warning Lamp
 Turns ON when there is a malfunction in 4WD system. 4W
D warning lamp indicates the vehicle is in fail-safe
mode.
 Also turns ON when ignition switch is turned ON, fo r the purpose of lamp check. Turns OFF approximately
for 1 second after the engine starts if system is normal.
ATP Warning Lamp
When the A/T shift selector is in P position, the vehicle may move if the transfer case in neutral. ATP warning
lamp is turned on to indicate this condition to the driver.
CONDITION FOR OPERATE WARNING BUZZER
For preventing an incorrect operation during 4H ⇔4L switching, warning buzzer sounds from inside of transfer
control unit and warns the driver, when certain conditions are satisfied.
4WD SYSTEM : Fail-SafeINFOID:0000000006303692
 If any malfunction occurs in 4WD electrical system, and control unit detects the malfunction, 4WD warning
lamp on combination meter turns ON to indicate system malfunction.
 When 4WD warning lamp is ON, vehicle changes to rear-wheel drive or shifts to 4-wheel drive (front-wheels
still have some driving torque).
Condition 4WD warning lamp
Lamp check Turns ON when ignition switch is turned ON. Turns OFF ap-
prox. 1 second after the engine start.
4WD system malfunction ON
Protection function is activated due to heavy load to transfer assem-
bly. (4WD system is not malfunctioning.) Quick blinking: 2 times/second
(Blinking in approx. 1 minute and then turning OFF)
Large difference in diameter of front/rear tires Slow blinking: 1 time/2 seconds
(Continuing to blink until turning ignition switch OFF)
Other than above (system normal) OFF
Condition Warning buzzer
4WD shift status A/T shift selector Engine speed
4H⇔4L N range 350
− 1.600 rpm OFF
Under 350 rpm or over 1.600 rpm ON
Except N range Always
Revision: 2010 May2011 QX56

DIAGNOSIS SYSTEM (TRANSFER CONTROL UNIT)
DLN-23
< SYSTEM DESCRIPTION > [TRANSFER: ATX90A]
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WORK SUPPORT
*: “LOCK SLEEVE SENSOR” means transfer lock position sensor.
VHCL/S SEN-RR [km/h] X Wheel speed (rear) average calculated by
transfer control.
ENG SPEED [rpm] X Engine status via CAN communication line is
displayed.
INTERNL SPEED SEN [count] X Transfer internal speed sensor status is dis-
played.
TRANSFER TORQUE [Nm] X Commanded transfer communication torque is
displayed.
UNIT PARAMETER [A1 - A9, B1 - B9, C1 - C9, D1
- D9, E1 - E9, F1 - F9, G1 - G9, H1 - H9, J1 - J9] Unit parameter of transfer recognized by trans-
fer control unit is displayed.
Monitor item (Unit)
SELECT MONITOR ITEM
Remarks
ECU INPUT
SIGNALS MAIN SIG-
NALS
Function Description
UNIT CHARACTERISTIC WRITE Writes the unit parameter of transfer to transfer control unit.
START CALIBRATION Perform initial calibration of transfer control unit.
LOCK SLEEVE SENSOR
* INITIALIZE Format learning the transfer lock position sensor written to transfer control unit.
LOCK SLEEVE SENSOR
* LEARNING Perform learning the transfer lock position sensor.
OIL DETERIORATION INFO RESET Format the transfer fl uid viscosity written to transfer control unit.
Revision: 2010 May2011 QX56

DLN-26
< ECU DIAGNOSIS INFORMATION >[TRANSFER: ATX90A]
TRANSFER CONTROL UNIT
*1: 4WD shift swich (2WD) is not equipped, but it is displayed.
*2: This indicator is not equipped, but it is displayed.
*3: This switch is not equipped, but it is displayed.
TERMINAL LAYOUT
PHYSICAL VALUES
COMPR VHCL SPEEDVehicle stopped 0.00 km/h (0.00 mph)
Vehicle driving
CAUTION:
Check air pressure of tire under standard condition. Approx. equal to the indication
on speedometer (inside of ±10
%)
VHCL/S SEN-FR Vehicle stopped 0.00 km/h (0.00 mph)
Vehicle driving
CAUTION:
Check air pressure of tire under standard condition. Approx. equal to the indication
on speedometer (inside of ±10
%)
VHCL/S SEN-RR Vehicle stopped 0.00 km/h
Vehicle driving
CAUTION:
Check air pressure of tire under standard condition. Approx. equal to the indication
on speedometer (inside of ±10
%)
ENGINE SPEED Engine running Approx. equal to the indication
on tachometer (inside of ±10 %)
INTRNL SPEED SEN 4WD mode: AUTO
A/T shift selector: DDepress the accelerator pedal several
times.
Value is changing
TRANSFER TORQUE 4WD shift switch: AUTO 0 - 2250 N·m
4WD shift switch: 4H 0 - 2250 N·m
4WD shift switch: 4L 0 Nm
UNIT PARAMETER Always A1 - A9
B1 - B9
C1 - C9
D1 - D9
E1 - E9F1 - F9
G1 - G9 H1 - H9 J1 - J9
Monitor item Condition Value/Status
JPDIE0229ZZ
Te r m i n a l N o .
(Wire color) Description
Condition Value (Approx.)
+ - Signal name Input/
Output
6
(BR) Ground Hi-Lo position sensor 1 Input/
Output Engine run-
ning
(Never
drive the
vehicle.) 4WD mode: AUTO or 4H 0 V
4WD mode: Shifting 0 V
4WD mode: 4L 5 V
Revision: 2010 May2011 QX56