brake fluid INFINITI QX56 2011 Factory Repair Manual

NORMAL OPERATING CONDITIONBRC-133
< SYMPTOM DIAGNOSIS > [WITH VDC]
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NORMAL OPERATING CONDITION
DescriptionINFOID:0000000006222669
Symptom Result
Brake pedal slightly vibrates and operation sound (motor sound and sound from suspen-
sion) occurs when VDC function, TCS function, ABS function, EBD function, hill start assist
function and brake limited slip differential (BLSD) function operates. This is not a malfunction, The symptom
occurs VDC function
, TCS function, ABS
function, EBD function, hill start assist
function and brake limited slip differential
(BLSD) function that are normally operat-
ed.
Brake stopping distance may become longer than models without ABS function depending
on the road conditions, when
ABS function is operated on slip pery road like rough road,
gravel road or snowy road.
Brake pedal vibrates and operation sound occurs during sudden acceleration and corner-
ing, when VDC function, TCS function, hill start assist function and brake limited slip differ-
ential (BLSD) function is operated.
Brake pedal vibrates and motor sound from the engine room occurs, when the engine starts
or the vehicle starts just after starting the engine This is not a malfunction. The symptom
occurs during the brake fluid accumula-
tion in the accumulator and operational
check of the ABS actuator and electric
unit (control unit).
Acceleration may be felt insufficient depending on the road conditions. This is not a malfunction. The symptom occurs TCS function that puts the highest
priority to obtain the optimum traction
(stability).
TCS may operate momentarily, while driving on a road where friction coefficient varies, or
when downshifting or fully depressing accelerator pedal
ABS warning lamp and VDC warning lamp may turn ON, when the vehicle is on a rotating
turntable or is given a strong shaking or large vibrations on a ship while the engine is run-
ning.
In this case, restart the engine on a nor-
mal road. If the normal condition is re-
stored, there is no malfunction. In that
case, erase self-diagnosis result memory
for “ABS” with CONSULT-III.
VDC warning lamp may turn ON and VDC function, TCS function, hill start assist function
and brake limited slip differential (BLSD) function may not normally operate, when driving
on a special road the is extremely slanted (bank in a circuit course).
A malfunction in yaw rate/side/decel G sensor system may be detected when the vehicle
sharply turns during a spin turn, acceleration turn or drift driving while VDC function and
TCS function are OFF (VDC OFF switch is pressed and VDC OFF indicator lamp is in ON
status).
The vehicle speed does not increase, when the accelerator pedal is depressed while the
vehicle is on a 2-wheel chassis dynamometer for speedometer check.
This is not malfunction. (When checking
the vehicle on a chassis dynamometer,
operate VDC OFF switch so that TCS
function is OFF.)
The VDC warning lamp, ABS warn ing lamp and brake warning lamp turn ON and DTC
“C118E” may be detected in self-diagnosis resu lt of “ABS” when the brake pedal is exces-
sively operated, such as air bleeding. This is not a system malfunction because
this occurs due to the temporary de-
crease in accumulator fluid pressure. The
system returns to no
rmal condition when
the accumulator fluid pressure reaches
the specified pressure with the ignition
switch ON and the VDC warning lamp,
ABS warning lamp, a nd brake warning
lamp turn OFF. After these steps, ABS
self-diagnosis results are erased.
VDC OFF indicator lamp turns ON and TCS function is not operate when 4WD mode is “4L”.
(Models with 4WD system) This is not a malfunction. When the 4WD
mode becomes “4L” state, the TCS func-
tion is disabled. This function is enabled
when the 4WD mode becomes “AUTO”
or “4H”.
Revision: 2010 May2011 QX56

COMPONENT PARTSBRC-143
< SYSTEM DESCRIPTION > [BRAKE ASSIST (WITH PREVIEW FUNCTION)]
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Component DescriptionINFOID:0000000006248457
× : Applicable
13. Steering angle sensor
Refer to BRC-10, "
Component Parts
Location"
14. ADAS control unit
Refer to DAS-13, "
Component Parts
Location"
A. Back side of engine room (RH) B. Front bumper (center) C. Upper side of brake pedal
D. Under side of instrument lower driver
panel
Component Function
Description
Vehicle-to-vehicle distance control mode
Conventional (fixed speed) cruise control mode Intelligent Brake Assist (IBA)
Brake Assist (with preview function)
ADAS control unit ×××× ADAS control unit calculates a target distance between vehicles
and a target speed, based on signals received from each sensor
and switch to transmit an engine torque command value to ECM
and a brake fluid pressure cont rol signal to ABS actuator and
electric unit (control unit) via CAN communication
 ADAS control unit transmits buzzer output signal to combination
meter via CAN communication
ICC sensor ×××× ICC sensor detects light reflected from a vehicle ahead by irra-
diating laser forward and calculates a distance from the vehicle
ahead and a relative speed, based on the detected signal
 ICC sensor transmits the presence/absence of vehicle ahead and the distance from the vehicle to ADAS control unit via ITS
communication
ECM ×××× ECM transmits the accelerator pedal position signal, ICC brake
switch signal, stop lamp switch signal, ICC steering switch sig-
nal, etc. to ADAS control unit via CAN communication
 ECM controls the electric throttle control actuator based on the engine torque demand received from the ADAS control unit via
CAN communication
ABS actuator and electric unit
(control unit) ×××× ABS actuator and electric unit (c
ontrol unit) transmits the vehicle
speed signal (wheel speed), stop lamp signal and VDC/TCS/
ABS system operation condition to ADAS control unit via CAN
communication
 ABS actuator and electric unit (c ontrol unit) controls the brake,
based on a brake fluid pressure control signal received from the
ADAS control unit via CAN communication
BCM ×BCM transmits the front wiper request signal to ADAS control unit
via CAN communication
TCM ××TCM transmits the signal related to A/T control to ADAS control
unit via CAN communication
Revision: 2010 May2011 QX56

BRC-150
< SYSTEM DESCRIPTION >[INTELLIGENT BRAKE ASSIST]
COMPONENT PARTS
Component Description
INFOID:0000000006248459
× : Applicable
13. Steering angle sensor
Refer to BRC-10, "
Component Parts
Location"
14. ADAS control unit
Refer to DAS-13, "
Component Parts
Location"
A. Back side of engine room (RH) B. Front bumper (center) C. Upper side of brake pedal
D. Under side of inst rument lower driver
panel
Component Function
Description
Vehicle-to-vehicle distance control mode
Conventional (fixed speed) cruise control mode Intelligent Brake Assist (IBA)
Brake Assist (with preview function)
ADAS control unit ×××× ADAS control unit calculates a target distance between vehicles
and a target speed, based on signals received from each sensor
and switch to transmit an engine torque command value to ECM
and a brake fluid pres sure control signal to ABS actuator and
electric unit (control unit) via CAN communication
 ADAS control unit transmits buzzer output signal to combination
meter via CAN communication
ICC sensor ×××× ICC sensor detects light reflected from a vehicle ahead by irra-
diating laser forward and calculates a distance from the vehicle
ahead and a relative speed, based on the detected signal
 ICC sensor transmits the presence/absence of vehicle ahead and the distance from the vehicle to ADAS control unit via ITS
communication
ECM ×××× ECM transmits the accelerator pedal position signal, ICC brake
switch signal, stop lamp switch signal, ICC steering switch sig-
nal, etc. to ADAS control unit via CAN communication
 ECM controls the electric throttle control actuator based on the engine torque demand received from the ADAS control unit via
CAN communication
ABS actuator and electric unit
(control unit) ×××× ABS actuator and electric unit (control unit) transmits the vehicle
speed signal (wheel speed), stop lamp signal and VDC/TCS/
ABS system operation condition to ADAS control unit via CAN
communication
 ABS actuator and electric unit (control unit) controls the brake, based on a brake fluid pressure control signal received from the
ADAS control unit via CAN communication
BCM ×BCM transmits the front wiper request signal to ADAS control unit
via CAN communication
TCM ××TCM transmits the signal related to A/T control to ADAS control
unit via CAN communication
Revision: 2010 May2011 QX56

CCS-10
< SYSTEM DESCRIPTION >[ICC]
COMPONENT PARTS
Component Description
INFOID:0000000006224266
× : Applicable
13. Steering angle sensor
Refer to BRC-10, "
Component Parts
Location"
14. ADAS control unit
Refer to DAS-13, "
Component Parts
Location"
A. Back side of engine room (RH) B. Front bumper (center) C. Upper side of brake pedal
D. Under side of inst rument lower driver
panel
Component Function
Description
Vehicle-to-vehicle distance control mode
Conventional (fixed speed) cruise control mode Intelligent Brake Assist (IBA)
Brake Assist (with preview function)
ADAS control unit ×××× ADAS control unit calculates a target distance between vehicles
and a target speed, based on signals received from each sensor
and switch to transmit an engine torque command value to ECM
and a brake fluid pres sure control signal to ABS actuator and
electric unit (control unit) via CAN communication
 ADAS control unit transmits buzzer output signal to combination
meter via CAN communication
ICC sensor ×××× ICC sensor detects light reflected from a vehicle ahead by irra-
diating laser forward and calculates a distance from the vehicle
ahead and a relative speed, based on the detected signal
 ICC sensor transmits the presence/absence of vehicle ahead and the distance from the vehicle to ADAS control unit via ITS
communication
ECM ×××× ECM transmits the accelerator pedal position signal, ICC brake
switch signal, stop lamp switch signal, ICC steering switch sig-
nal, etc. to ADAS control unit via CAN communication
 ECM controls the electric throttle control actuator based on the engine torque demand received from the ADAS control unit via
CAN communication
ABS actuator and electric unit
(control unit) ×××× ABS actuator and electric unit (control unit) transmits the vehicle
speed signal (wheel speed), stop lamp signal and VDC/TCS/
ABS system operation condition to ADAS control unit via CAN
communication
 ABS actuator and electric unit (control unit) controls the brake, based on a brake fluid pressure control signal received from the
ADAS control unit via CAN communication
BCM ×BCM transmits the front wiper request signal to ADAS control unit
via CAN communication
TCM ××TCM transmits the signal related to A/T control to ADAS control
unit via CAN communication
Revision: 2010 May2011 QX56

CCS-14
< SYSTEM DESCRIPTION >[ICC]
SYSTEM
Output Signal Item
DESCRIPTION
Intelligent Cruise Control
The Intelligent Cruise Control (ICC) system maintains a se
lected distance from the vehicle in front of own vehi-
cle within the speed range of 0 to 144 km/h (0 to 90 MPH) up to the set speed.
The set speed can be selected by the driver between 32 to 144 km/h (20 to 90 MPH).
The vehicle travels at a set speed when the road ahead is clear.
The ICC system can be set to one of two cruise control modes:
CAUTION:
Never set the cruise speed exceed ing the posted speed limit.
Vehicle-to-vehicle Distance Control Mode
ICC sensorITS com-
munica-
tionICC sensor signal
Receives detection results, such as the presence or ab-
sence of a leading vehicle and distance from the vehicle
IBA OFF switch IBA OFF switch signal Receives an ON/OFF state of the IBA OFF switch Transmit unit Signal name Description
Reception unit Signal name Description
ECM CAN commu-
nicationICC operation signal
Transmits an ICC operation signal necessary for Intel-
ligent Cruise Control
TCM CAN commu-
nicationICC operation signal Transmits an ICC operation signal necessary for Intel-
ligent Cruise Control via ECM
ABS actuator
and electric
unit (control
unit) CAN commu-
nication
Brake fluid pressure control signal
Transmits a brake fluid pressure control signal to acti-
vates the brake
Combination
meter CAN commu-
nicationMeter display
signal Own vehicle indicator
signal
Transmits a signal to display a state of the system on
the information display
Vehicle ahead detec-
tion indicator signal
Set vehicle speed indi-
cator signal
Set distance indicator
signal
SET switch indicator
signal
MAIN switch indicator
signal
ICC warning lamp signal Transmits an ICC warning lamp signal to turn ON the
ICC system warning lamp
IBA OFF indicator lamp signal  Transmits a signal to turn ON the IBA OFF indicator
lamp
 Transmits an ON/OFF state of the intelligent brake
assist
Buzzer output signal Transmits a buzzer output signal to turn ON the buzz-
er of the following systems:
 Intelligent Cruise Control (ICC)
 Intelligent Brake Assist (IBA)
ICC sensor ITS commu-
nication
Vehicle speed signal Transmits a vehicle speed calculated by the ADAS
control unit
ICC brake hold
relay ICC brake hold relay drive signal
Activates the brake hold relay and turns ON the stop
lamp
Revision: 2010 May2011 QX56

CCS
SYSTEMCCS-17
< SYSTEM DESCRIPTION > [ICC]
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With ICC system, the driver can maintain the same speed as other vehicles without the constant need to
adjust the set speed as driver would with a normal cruise control system.
The following items are controlled in the vehicle-to-vehicle distance control mode
 When there are no vehicles traveling ahead, the vehi cle-to-vehicle distance control mode maintains the
speed set by the driver. The set speed range is between approximately 32 and 144 km/h (20 and 90 MPH).
 When there is a vehicle traveling ahead, the vehicle- to-vehicle distance control mode adjusts the speed to
maintain the distance, selected by driver, from a vehicle ahead. The adjusting speed range is up to the set
speed.
 When the vehicle traveling ahead has moved out from its lane of travel, the vehicle-to-vehicle distance con-
trol mode accelerates and maintains vehicle speed up to the set speed.
CAUTION:
If the vehicle ahead comes to stop, the vehicle decel erates to a standstill within the limitations of the
system. The system will cancel once it judges that the vehicle has come to a standstill and sound a
warning chime.
To prevent the vehicle from moving, th e driver must depress the brake pedal.
NOTE:
When the accelerator pedal is depressed, the brake oper ation and the warning are not performed by the ICC
system.
OPERATION DESCRIPTION
Quickly push (less than 1.5 seconds) and release the MAIN switch ON.
The MAIN switch indicator, set distance indicator, own vehicle indicator, and set vehicle speed indicator come
on and ICC system is set to a standby state.
ADAS control unit performs the control as per the following:
Set Condition
Under a standby state, pushing down the SET/ COAST switch will start system control.
 When vehicle speed is between approximately 32 km/h and 144 km/h (20 MPH and 90 MPH).
 When vehicle speed is below approximately 32 km/h ( 20 MPH) if the vehicle ahead is detected. The set
vehicle speed becomes 32 km/h (20 MPH).
If the system is canceled by conditi ons 1-6 below, the system will resume c ontrol at the last set cruising speed
by pushing up the RESUME/ACCELERATE switch.
NOTE:
 When the SET/COAST switch is pushed under the following condi- tions, the system cannot be set and the set vehicle speed indicator
will blink for approximately 2 seconds.
- When traveling below 32 km/h (20 MPH) and the vehicle ahead is not detected.
- When the selector lever is not in the “D” position or manual mode.
- When the front wipers are operating at HI.
(If the vehicle is equipped with a rain sensing auto-wiper, the sys-
tem may cancel when the wipers are set to AUTO)
- When the parking brakes are applied.
- When the brakes are operated by the driver.
Constant
speed Comparing the set vehicle speed with the current vehicle speed, transmit the command to ECM via CAN communication
to reach the set vehicle speed, and controls the electric throttle control actuator
Decelera-
tion When a vehicle ahead (slower than driver set vehicle speed) appears or when a vehicle ahead slows down, the system
controls the electric throttle control actuator into the close direction and decelerates the vehicle. If greater deceleration
is necessary, the system
transmits the brake fluid pressure control signal to the ABS actuator and electric unit (control
unit) via CAN communication and operates the brake
Following The system controls the electric throttle control actuator and the brake fluid pressure to keep the proper distance between
the vehicles according to the vehicle speed change of the vehicle ahead
Accelera-
tion When a vehicle ahead is not detected because of it changes lanes or own vehicle changes lanes during the following
driving, the system controls the electric throttle control actu
ator in the open direction and accelerates the vehicle to the
set vehicle speed slowly
JPOIA0222ZZ
Revision: 2010 May2011 QX56

CCS-38
< SYSTEM DESCRIPTION >[ICC]
DIAGNOSIS SYSTEM (ADAS CONTROL UNIT)
STOP LAMP
ICC BUZZER
BRAKE ACTUATOR
NOTE:
The test can be performed only when the engine is running.
NOTE:
The test is finished in 10 seconds after starting
Te s t i t e mOper-
ation Description  MAIN switch indicator
 ICC system warning lamp
 IBA OFF indicator lamp
METER LAMP Off
Stops sending the following signals to exit from the test
 Meter display signal
 ICC warning lamp signal
 IBA OFF indicator lamp signal OFF
On Transmits the following signals to the combination meter via
CAN communication
 Meter display signal
 ICC warning lamp signal
 IBA OFF indicator lamp signal
ON
Te s t i t e m
Oper-
ation Description Stop lamp
STOP LAMP Off
Stops transmitting the ICC brake hold relay drive signal be-
low to end the test OFF
On Transmits the ICC brake hold relay drive signal ON
Test item Operation Description ICC warning chime operation
sound
ICC BUZZER MODE1
Transmits the buzzer output signals to the combination
meter via CAN communication Intermittent beep sound
Test start Starts the tests of “MODE1” — Reset Stops transmitting the buzzer output signal below to end
the test —
End Returns to the “SELECT TEST ITEM” screen —
Test item Operation Description “PRESS SENS” value
BRAKE ACTUATOR MODE1
Transmits the brake fluid pressure control signal to the
ABS actuator and electric unit (control unit) via CAN
communication 10 bar
MODE2 20 bar
MODE3 30 bar
Test start Starts the tests of “MODE1”, “MODE2” and “MODE3” —
Reset Stops transmitting the brake fluid pressure control signal
below to end the test —
End Returns to the “SELECT TEST ITEM” screen —
PKIB1767J
Revision: 2010 May2011 QX56

DAS-16
< SYSTEM DESCRIPTION >[ADAS CONTROL UNIT]
SYSTEM
Output Signal Item
AV control unitCAN com-
munica-
tionSystem selection signal
Receives a selection state of each item in “Driver Assis-
tance” selected with the navigation system
A/C auto amp. CAN com-
munica-
tion
Ambient temperature signal Receives ambient temperature signal
Transfer control
unit CAN com-
munica-
tion
Current 4WD mode signal Receives a mode selection state of the 4WD shift switch
ICC sensor ITS com-
munica-
tionICC sensor signal
Receives detection results, such as the presence or ab-
sence of a vehicle ahead and distance from the vehicle
Lane camera
unit ITS com-
munica-
tion
Detected lane condition signal Receives detection results of lane marker
Accelerator
pedal actuator ITS com-
munica-
tionAccelerator pedal actuator operation status
signal
Receives an operational state of accelerator pedal ac-
tuator
Side radar LH,
RH ITS com-
munica-
tion
Vehicle detection signal Receives vehicle detection condition of detection zone
IBA OFF switch IBA OFF switch signal Receives an ON/OFF state of the IBA OFF switch
Warning sys-
tems switch Warning systems switch signal
Receives an ON/OFF state of the warning systems
switch
Transmit unit Signal name Description
Reception unit Signal name Description
ECM CAN commu-
nicationICC operation signal Transmits an ICC operation signal necessary for intel-
ligent cruise control
TCM CAN commu-
nication
ICC operation signal Transmits an ICC operation signal necessary for intel-
ligent cruise control via ECM
ABS actuator
and electric
unit (control
unit) CAN commu-
nication
Brake fluid pressure control signal
Transmits a brake fluid pressure control signal to acti-
vates the brake
Target yaw moment signal Transmits a target yaw moment signal to generate
yaw moment to the vehicle
Revision: 2010 May2011 QX56

DAS-28
< SYSTEM DESCRIPTION >[ADAS CONTROL UNIT]
DIAGNOSIS SYSTEM (ADAS CONTROL UNIT)
STOP LAMP
ICC BUZZER
BRAKE ACTUATOR
NOTE:
The test can be performed only when the engine is running.
NOTE:
The test is finished in 10 seconds after starting
Te s t i t e mOper-
ation Description  MAIN switch indicator
 ICC system warning lamp
 IBA OFF indicator lamp
METER LAMP Off
Stops sending the following signals to exit from the test
 Meter display signal
 ICC warning lamp signal
 IBA OFF indicator lamp signal OFF
On Transmits the following signals to the combination meter via
CAN communication
 Meter display signal
 ICC warning lamp signal
 IBA OFF indicator lamp signal
ON
Te s t i t e m
Oper-
ation Description Stop lamp
STOP LAMP Off
Stops transmitting the ICC brake hold relay drive signal be-
low to end the test OFF
On Transmits the ICC brake hold relay drive signal ON
Test item Operation Description ICC warning chime operation
sound
ICC BUZZER MODE1
Transmits the buzzer output signals to the combination
meter via CAN communication Intermittent beep sound
Test start Starts the tests of “MODE1” — Reset Stops transmitting the buzzer output signal below to end
the test —
End Returns to the “SELECT TEST ITEM” screen —
Test item Operation Description “PRESS SENS” value
BRAKE ACTUATOR MODE1
Transmits the brake fluid pressure control signal to the
ABS actuator and electric unit (control unit) via CAN
communication 10 bar
MODE2 20 bar
MODE3 30 bar
Test start Starts the tests of “MODE1”, “MODE2” and “MODE3” —
Reset Stops transmitting the brake fluid pressure control signal
below to end the test —
End Returns to the “SELECT TEST ITEM” screen —
PKIB1767J
Revision: 2010 May2011 QX56

DAS
COMPONENT PARTSDAS-67
< SYSTEM DESCRIPTION > [DCA]
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Component DescriptionINFOID:0000000006223499
Component Description
ADAS control unit  ADAS control unit calculates a target distance between vehicles and a target speed,
based on signals received from each sensor and switch to transmit a brake fluid pres-
sure control signal to ABS actu ator and electric unit (control unit) via CAN communica-
tion
 ADAS control unit transmits the buzzer output signal to the combination meter via CAN communication
 ADAS control unit transmits an accelerator pedal feedback force control signal to the accelerator pedal actuator via ITS communication
ICC sensor  ICC sensor detects light reflected from a vehicle ahead by irradiating laser forward and
calculates a distance from the vehicle ahead and a relative speed, based on the detect-
ed signal
 ICC sensor transmits the presence/absence of vehicle ahead and the distance from the vehicle to ADAS control unit via ITS communication
ECM ECM transmits the accelerator pedal position signal, ICC brake switch signal, stop lamp
switch signal, ICC steering switch signal, etc. to ADAS control unit via CAN communica-
tion
ABS actuator and electric unit (control
unit)  ABS actuator and electric unit (control unit
) transmits the vehicle speed signal (wheel
speed), stop lamp signal and VDC/TCS/ABS system operat ion condition to ADAS con-
trol unit via CAN communication
 ABS actuator and electric unit (control unit ) controls the brake, based on a brake fluid
pressure control signal received from ADAS control unit via CAN communication
TCM TCM transmits the signal related to A/T control to ADAS control unit via CAN communi-
cation
Combination meter Performs the following operations using the signals received from the ADAS control unit
via the CAN communication
 Displays the DCA system operation status using the meter display signal
 Illuminates the ICC system warning lamp using the ICC warning lamp signal
 Operates the buzzer (ICC warning chime) using the buzzer output signal
Dynamic driver assistance switch
(On the ICC steering switch) ECM receives an ICC steering switch (dynamic driver assistance switch) signal and trans-
mits the signal to ADAS control unit via CAN communication
ICC brake hold relay ICC brake hold relay activates the stop lamp by ICC brake hold relay drive signal (stop
lamp drive signal) outputted by the ADAS control unit
ICC brake switch  ICC brake switch is turned OFF and stop lamp switch is turned ON, when depressing the brake pedal
 ICC brake switch signal is input to ECM. These signals are transmitted from ECM to ADAS control unit via CAN communication
 Stop lamp switch signal is input to ECM and ABS actuator and electric unit (control unit). These signals are transmitted from ECM and ABS actuator and electric unit (control
unit) to ADAS control unit via CAN communication
Stop lamp switch
Transfer control unit
Transfer control unit transmits a mode selection state of 4WD shift switch to the ADAS
control unit via CAN communication
AV control unit AV control unit transmits the system selection signal to the ADAS control unit via CAN
communication
Steering angle sensor Measures the rotation amount, rotation speed, and rotation direction of steering wheel,
and then transmits them to ADAS control unit via CAN communication
Accelerator pedal actuator Accelerator pedal actuator receives an accelerator pedal feedback force control signal
from the ADAS control unit via ITS communication and pushes back the accelerator pedal
Revision: 2010 May2011 QX56