2011 INFINITI QX56 ABS

BRC-144
< SYSTEM DESCRIPTION >[BRAKE ASSIST (WITH PREVIEW FUNCTION)]
COMPONENT PARTS
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 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
St op la mp sw i tc h
××××
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

SYSTEM
BRC-145
< SYSTEM DESCRIPTION > [BRAKE ASSIST (WITH PREVIEW FUNCTION)]
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SYSTEM
BRAKE ASSIST (WITH PREVIEW FUNCTION)
BRAKE ASSIST (WITH PREVIEW F UNCTION) : System DescriptionINFOID:0000000006228293
FUNCTION DESCRIPTION
When the Preview Function identifies the need to apply emergency braking by sensing a vehicle ahead in the
same lane and the distance and relative speed from it, it applies the brake pre-pressure before the driver
depress the brake pedal and helps improve brake response by reducing pedal free play.
The Preview Function shares component parts and diagnosis with the Intelligent Cruise Control (ICC) system.
CAUTION:
This system is only an aid to assist braking oper ation and is not a collision warning or avoidance
device. It is the driver ′s responsibility to stay aler t, drive safely and be in control of the vehicle at all
times.
OPERATION DESCRIPTION
 The system detects the distance to the vehicle in fr ont with the ICC sensor of ICC and judges the necessity
of emergency braking.
 The system detects the accelerator pedal release operati on of the driver by the accelerator pedal position
sensor and estimates the driver's brake operation intention.
 If the system is judged that the emergency braking is nec essary and that the driver has the intention to oper-
ate the brake, the ABS actuator and electric unit (control unit) applies pre-pressure to reduce brake pedal
play.
NOTE:
This system will not operate under the following conditions:
 When the vehicle is moving at approx imately 32 km/h (20 MPH) or less.
 When the 4WD shift switch is in the 4H or 4L position.
END OF OPERATION
The pre-pressure function ceases when the following conditions are met:
1. When the driver depresses the acce lerator pedal or the brake pedal.
2. If the driver does not operate the accelerator pedal or brake pedal within approximately 1 second.
Revision: 2010 May2011 QX56

NORMAL OPERATING CONDITIONBRC-147
< SYMPTOM DIAGNOSIS > [BRAKE ASSIST (WITH PREVIEW FUNCTION)]
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SYMPTOM DIAGNOSIS
NORMAL OPERATING CONDITION
DescriptionINFOID:0000000006228295
PRECAUTIONS FOR PREVIEW FUNCTION
 This system is only an aid to assist braking operation and is not a collision warning or avoidance device. 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 to the Preview Function, never rely solely on this system. This system does
not correct careless inattentive or absent-minded driving, or overcome poor visibility in rain, fog, or other bad
weather. Reduce vehicle speed by depressing the brake pedal , in order to maintain a safe distance between
vehicles.
 The system may not detect a vehicle ahead, depending on road or weather conditions. While the vehicle still
travels and the Brake Assist Syst em operates under normal conditions, the Preview Function may operate
improperly under the following conditions:
- When rain, snow or dirt adhere to the system sensor
- When strong light (for example, at sunrise or sunset ) is directly shining on the front of the vehicle
- Winding or hilly roads may cause the sensor to tem porarily not detect a vehicle in the same lane or may
detect objects or vehicles in other lanes.
- Vehicle position in the lane may cause the sensor to te mporarily not detect a vehicle in the same lane or may
detect objects or vehicles in other lanes.
 The system will not detect:
- Pedestrians or objects in the roadway
- Oncoming vehicles in the same lane
- Motorcycles traveling offset in the travel lane as illustrated
 When the Preview Function operates, the brake pedal may move slightly and may make a small noise. This is not a system malfunc-
tion.
JSFIA0390ZZ
Revision: 2010 May2011 QX56

COMPONENT PARTSBRC-149
< SYSTEM DESCRIPTION > [INTELLIGENT BRAKE ASSIST]
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SYSTEM DESCRIPTION
COMPONENT PARTS
Component Parts LocationINFOID:0000000006248458
1. ICC steering switch 2. Information display, ICC system warning lamp, IBA OFF indicator
lamp, buzzer
(On the combination meter)3. BCM
Refer to BCS-4, "
BODY CONTROL
SYSTEM : Compon ent Parts Loca-
tion"
4. Transfer control unit
Refer to DLN-10, "
Component Parts
Location"
5. ICC brake hold relay 6. ECM
Refer to EC-16, "
Component Parts
Location"
7. ICC sensor 8. TCM
Refer to TM-10, "
A/T CONTROL
SYSTEM : Compon ent Parts Loca-
tion"
9. ABS actuator and electric unit (con-
trol unit)
Refer to BRC-10, "
Component Parts
Location"
10. Stop lamp switch 11. ICC brake switch 12. IBA OFF switch
JSOIA0362ZZ
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

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

BRM-4
< PRECAUTION >
REPAIRING HIGH STRENGTH STEEL
PRECAUTION
REPAIRING HIGH STRENGTH STEEL
High Strength Steel (HSS)INFOID:0000000006248484
High strength steel is used for body panels in order to reduce vehicle weight.
Accordingly, precautions in repairing automotive bodies made of high strength steel are described below:
Read the following precautions when repairing HSS:
1. Additional points to consider
Tensile strength Major applicable parts 440 - 780 MPa  Rear floor reinforcement
 2nd seat mounting member assembly
 Front seat mounting rear crossmember assembly
 Front floor reinforcement
 2nd crossmember (Lower)
 Side radiator core support
 Radiator core support main assembly
 Front side member assembly
 4th crossmember
 2nd seat mounting crossmember
 Rear side member
 Rear crossmember
 Inner side roof rail
 Upper inner front pillar
 Inner center pillar
 Upper front pillar reinforcement
 Lower center pillar brace
 Front pillar brace
 Outer sill reinforcement
 Front roof rail
 Rear roof rail
 Radiator guard crossmember assembly
 2nd crossmember assembly
 2nd crossmember reinforcement
 Front side member assembly
 Front bound bumper bracket assembly
 Lower front link mounting bracket assembly
 Center side member assembly
 Fuel tank protector assembly
 Rear suspension mounting bracket assembly
 Rear shock absorber bracket assembly
 Rear side member assembly
 Rear end gusset
 Rear end crossmember assembly
980 - 1350 MPa  Lower dash center reinforcement
(Lower dash Component part)
 Inner sill
 Rear seat crossmember
(2nd seat mounting crossmember component part)
 Inner center pillar (Upper)
 Upper outer center pillar reinforcement
(Lower center pillar brace component part)
 Front bumper crossmember assembly
Revision: 2010 May2011 QX56

BRM-14
< PREPARATION >
BODY COMPONENT PARTS
NOTE:
 For the parts without a number described in the figure, it is supplied only with the assembly part that the part is included with.
 Tensile strength column shows the largest strength value of a part in the component part.
CAUTION:
If the high strength steel (ultra high strength steel) of this is broken, replace by assembly for the supply part. No. Parts name
Tensile strength
(MPa) Both sided anti-corrosive
precoated steel sections
1. Frame assembly Refer to No.2−36
2. Front bumper crossmember assembly T=1.8 mm
(0.071 in)
980
caution—
3. 2nd crossmember assembly 440 —
4. 2nd crossmember reinforcement (RH & LH) 440 —
5. 1st cab mounting bracket (RH & LH) Under 440 —
6. Front side member assembly (RH & LH) 540 —
7. Front suspension bracket assembly (RH & LH) Under 440 —
8. Engine mounting bracket assembly (RH & LH) Under 440 —
9. 2nd cab mounting bracket assembly (RH & LH) Under 440 —
10. 3way connector bracket assembly (RH & LH) Under 440 —
11. Piping bracket assembly (RH & LH) Under 440 —
12. Front bound bumper bracket assembly (RH & LH) 540 —
13. Lower front link mounting bracket assembly (RH & LH) 440 —
14. Diagonal member complete (RH & LH) 540 —
15. Rear engine mounting gusset assembly Under 440 —
16. Rear engine mounting member complete Under 440 —
17. Front fuel tank protector (RH & LH) Under 440 —
18. 3rd cab mounting bracket assembly (RH & LH) Under 440 —
19. Center side member assembly (RH & LH) 540 —
20. 6th crossmember assembly Under 440 —
21. Exhaust bracket (Front) Under 440 —
22. Fuel tank protector (RH & LH Rear) Under 440 —
23. Heat insulator bracket Under 440 —
24. Fuel tank protector assembly (RH & LH) 540 —
25. Rear suspension mounting bracket assembly (RH & LH) 540 —
26. 4th cab body mounting bracket assembly (RH & LH) Under 440 —
27. Rear brake hose bracket (RH & LH) Under 440 —
28. Rear shock absorber bracket assembly (RH & LH) 540 —
29. Rear side member assembly (RH & LH) 540 —
30. 5th cab body bracket (RH & LH) Under 440 —
31. 7th crossmember assembly Under 440 —
32. Exhaust bracket (Rear) Under 440 —
33. Spare wheel crossmember assembly Under 440 —
34. Front under cover bracket assembly Under 440 —
35. Rear end gusset (RH & LH) 440 —
36. Rear end crossmember assembly 540 —
Revision: 2010 May2011 QX56