2011 INFINITI QX56 brake

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

COMPONENT PARTSBRC-151
< SYSTEM DESCRIPTION > [INTELLIGENT BRAKE ASSIST]
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NOTE:
Only IBA system uses
Combination meter ××××Performs the following operations using the signals received from
the ADAS control unit via the CAN communication
 Displays the ICC system operation status using the meter dis-
play signal
 Illuminates the ICC system warning lamp using the ICC warning
lamp signal
 Illuminates the IBA OFF indicator lamp using the IBA OFF indi- cator lamp signal
 Operates the buzzer (ICC warning chime) using the buzzer out- put signal
ICC steering switch ×× ICC steering switch allows the ON/OFF of the Intelligent Cruise
Control and the settings of a vehicle speed and distance be-
tween vehicles
 ICC steering switch signal is transmitted to ECM. ECM transmits the signal to the ADAS control unit via CAN communication
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 communi-
cation
 Stop lamp switch signal is in put 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
××××
ICC brake hold relay ××ICC brake hold relay activates the stop lamp by ICC brake hold re-
lay drive signal (stop lamp drive signal) outputted by the ADAS
control unit
Transfer control unit ××××Transfer control unit transmits a mode selection state of 4WD shift
switch to the ADAS control unit via CAN communication
IBA OFF switch ×
NoteIBA OFF switch signal is input to the ADAS control unit
Steering angle sensor ×Measures the rotation amount, rotation speed, and rotation direc-
tion of steering wheel, and then transmits them to ADAS control
unit via CAN communication
Component
Function
Description
Vehicle-to-vehicle distance control mode
Conventional (fixed speed) cruise control mode Intelligent Brake Assist (IBA)
Brake Assist (with preview function)
Revision: 2010 May2011 QX56

BRC-152
< SYSTEM DESCRIPTION >[INTELLIGENT BRAKE ASSIST]
SYSTEM
SYSTEM
INTELLIGENT BRAKE ASSIST
INTELLIGENT BRAKE ASSIST : System DescriptionINFOID:0000000006228299
FUNCTION DESCRIPTION
Intelligent Brake Assist (IBA) syst
em warns the driver by a vehicle ahead detection indicator and chime when
there is a risk of a collision with the vehicle ahead in the traveling lane and the driver must take avoidance
action immediately. The system helps reduce the rear -end collision speed by applying the brakes when it
judges a collision can not be avoided.
CAUTION:
The IBA system is a not collision avoidance system. It is the driver ′s responsibility to stay alert, drive
safely and be in control of the vehicle at all times. As there is a performance limit, it may not provide a
warning or brake in certain conditions.
NOTE:
 The IBA system shares component parts and diagnosis wi th the Intelligent Cruise Control (ICC) system.
New parts added to the IBA system is the IBA OFF indica tor lamp in the combination meter and the IBA OFF
switch on the instrument driver lower panel.
 The ICC sensor integrated unit shares the parts with the ICC, but the IBA system will operate even when the
ICC system is turned to OFF.
OPERATION DESCRIPTION
The IBA system uses an ICC sensor located below t he front bumper to measure the distance to a vehicle
ahead. When the system judges that the distance gets shorter, the vehicle ahead detection indicator on the
combination meter blinks and the warning chime sounds.
To turn the system OFF/ON, push and hold the IBA OFF switch after starting the engine for more than 1 sec-
ond.
NOTE:
 The system ON/OFF condition will be memorized even if the ignition switch turns OFF.
 The IBA system operates under the following conditions.
- The IBA system will function when the vehicle is driv en at speeds of approximately 15 km/h (10 MPH) and
above, and when the vehicle ′s speed is approximately 15 km/h (10 MPH) faster than that of the vehicle
ahead.
Switch and Indicators
Temporary unavailable indication
1. IBA OFF switch 2. Vehicle ahead detection indicator 3. IBA OFF indicator lamp
A. Under side of Instrument lower panel
(LH) B. On the combination meter
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Revision: 2010 May2011 QX56

SYSTEM
BRC-153
< SYSTEM DESCRIPTION > [INTELLIGENT BRAKE ASSIST]
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Fail-safe Indication
NOTE:
When the IBA turns OFF, the IBA OFF indicator lamp will illuminate.
Condition Description Indication on the combination meter
When the 4WD shift switch is in the 4H or
4L position The system is temporary unavailable.
(Without the warning chime)
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Condition Description Indication on the combination meter
 When the sensor window is dirty
 When the system malfunction The system will be cancelled automatically
with a beep sound.
When driving into a strong light
(i.e. sunlight) The system is temporary unavailable.
(Without the warning chime)
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Revision: 2010 May2011 QX56

BRC-154
< DTC/CIRCUIT DIAGNOSIS >[INTELLIGENT BRAKE ASSIST]
INTELLIGENT BRAKE ASSIST
DTC/CIRCUIT DIAGNOSIS
INTELLIGENT BRAKE ASSIST
Diagnosis ProcedureINFOID:0000000006228300
1.INTELLIGENT BRAKE ASSIST DIAGNOSIS
 The system will be cancelled automatically with a beep sound and IBA OFF indicator lamp on the combina-
tion meter will illuminate, when the system will not operate properly.
 When the IBA OFF indicator lamp continues to illumi nate even if the IBA system is turned on after the engine
restarts, perform the trouble-diagnosis.
NOTE:
IBA system automatically returns to ON, when erasing self-diagnosis result of “ICC/ADAS” with CONSULT-III.
>> Go to ICC. Refer to CCS-69, "
Work Flow".
Revision: 2010 May2011 QX56

SWITCH DOES NOT TURN ON / SWITCH DOES NOT TURN OFF
BRC-155
< SYMPTOM DIAGNOSIS > [INTELLIGENT BRAKE ASSIST]
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SYMPTOM DIAGNOSIS
SWITCH DOES NOT TURN ON / SWITCH DOES NOT TURN OFF
Symptom TableINFOID:0000000006228301
CAUTION:
Perform the self-diagnosis with CONS ULT-III before the symptom diagnosis. Perform the trouble diag-
nosis if any DTC is detected.
DescriptionINFOID:0000000006228302
IBA system does not turn ON/OFF.
 IBA OFF indicator lamp does not illuminate even if the IBA OFF switch is depressed when IBA OFF indicator
lamp is not illuminated.
 IBA OFF indicator lamp does not turn off even if t he IBA OFF switch is depressed when IBA OFF indicator
lamp is illuminated.
NOTE:
 To turn the system OFF ⇔ON, push and hold the IBA OFF switch after starting the engine for more than 1
second.
 The system ON/OFF condition will be memoriz ed even if the ignition switch turns OFF.
Diagnosis ProcedureINFOID:0000000006228303
1.PERFORM THE SELF-DIAGNOSIS
1. Perform “All DTC Reading” with CONSULT-III.
2. Check if the DTC is detected in self-diagnosis results for “ICC/ADAS” with CONSULT-III. Refer to CCS-50,
"DTC Index".
Is any DTC detected?
YES >> GO TO 6.
NO >> GO TO 2.
2.IBA OFF SWITCH INSPECTION
1. Start the engine.
2. Check that “IBA SW” operates normally in “D ATA MONITOR” for “ICC/ADAS” with CONSULT-III.
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 5.
3.CHECK IBA OFF INDICATOR CIRCUIT
1. Start the engine.
2. Select the active test item “METE R LAMP” for “ICC/ADAS” with CONSULT-III.
3. Check if the IBA OFF indicator lamp illuminates when the test item is operated.
Is the inspection result normal?
YES >> Refer to CCS-69, "Work Flow".
NO >> GO TO 4.
4.CHECK DATA MONITOR OF COMBINATION METER
Check that “BA W/L” operates normally in “DATA MO NITOR” for “METER/M&A” with CONSULT-III, when the
IBA OFF switch is pushed and hold for more than 1 second.
Is the inspection result normal?
YES >> Replace the combination meter. Refer to MWI-85, "Removal and Installation".
NO >> Replace the ADAS control unit. Refer to DAS-63, "
Removal and Installation".
Symptom Inspection item/Reference page
IBA system does not turn ON/OFF IBA OFF indicator lamp is not turned
ON
⇔OFF when operating IBA OFF switch BRC-155, "
Diagnosis Procedure"
Revision: 2010 May2011 QX56

BRC-156
< SYMPTOM DIAGNOSIS >[INTELLIGENT BRAKE ASSIST]
SWITCH DOES NOT TURN ON /
SWITCH DOES NOT TURN OFF
5.CHECK IBA OFF SWITCH
Check IBA OFF switch. Refer to CCS-127, "
Component Inspection (IBA OFF Switch)".
Is the inspection result normal?
YES >> GO TO 7.
NO >> GO TO 6.
6.REPAIR OR REPLACE MALFUNCTIONING PARTS
Repair or replace malfunctioning parts.
>> GO TO 7.
7.CHECK IBA SYSTEM
Check that IBA OFF indicator lamp turned ON ⇔OFF, when operating IBA OFF switch.
>> INSPECTION END
Revision: 2010 May2011 QX56

NORMAL OPERATING CONDITIONBRC-157
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NORMAL OPERATING CONDITION
DescriptionINFOID:0000000006228304
PRECAUTIONS FOR INTELLIGENT BRAKE ASSIST
 The IBA system is a not collision avoidance system. It is the driver′s responsibility to stay alert, drive safely
and be in control of the vehicle at all times.
 As there is a performance limit, it may not prov ide a warning or brake in certain conditions.
 The system will not detect the following objects:
- Pedestrians, animals, or obstacles in the roadway
- Oncoming vehicles in the same lane
 The system will not detect under the following conditions:
- When the sensor gets dirty and it is impossibl e to detect the distance from the vehicle ahead.
- When driving into a strong light (i.e. sunlight)
 The sensor generally detects the signals returned from the reflectors on a vehicle ahead. Therefore, the sys-
tem may not function properly under the following conditions:
- When the reflectors of the vehicle ahead are positioned high or close each other (including a small vehicle
such as motorcycles).
- When the sensor gets dirty or and it is impossi ble to detect the distance from the vehicle ahead.
- When the reflectors on the vehicle ahead is missing, damaged or covered.
- When the reflector of the vehicle ahead is covered with dirt, snow and road spray.
- When visibility is low (such as rain, fog, snow, etc.).
- When snow or road spray from traveling vehicles are raised up.
- When dense exhaust or other smoke (black smoke) fr om vehicles reduces the sensor visibility.
- When excessively heavy baggage is loaded in the rear seat or the luggage room of vehicle.
- When abruptly accelerating or decelerating.
- On steep downhill or roads with sharp curves.
- When there is a highly reflective object near the vehicle ahead (i.e. very close to other vehicle, signboard,
etc.).
- While towing a trailer or other vehicle.
 Depending on certain road conditions (curved, beginning of a curve), vehicle conditions (steering position,
vehicle position), or preceding vehicle ′s conditions (position in lane, etc. ), the system may not function prop-
erly.
 The system may not function in offset conditions.
 The system may not function when the distanc e to the vehicle ahead is extremely close.
 The system detect highly reflective objects such as reflectors, signs, white markers, and other stationary objects on the road or
near the traveling lane, and when in extreme conditions, detection
of these objects may caus e the system to function.
 The system is designed to automatically check the sensor ′s func-
tionality. If the sensor is covered with ice, a transparent or translu-
cent plastic bag, etc., the system may not detect them. In these
instances the system may not be able to warn properly. Be sure to
check and clean the sensor regularly.
 Excessive noise will interfere with the warning chime sound, and the chime may not be heard.
 Never step in under the brake pedal to avoid an accident when IBA
system turns ON.
 Sudden appearance of the vehicle in front (i.e. it abrupt ly cuts in) may not be detected and the system may
not warn soon enough.
 The system will be cancelled automatically with a beep sound and the IBA OFF indicator lamp will illuminate
under the following conditions:
- When the sensor window is dirty
- When the system malfunctions
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Revision: 2010 May2011 QX56