Infiniti QX56 (Z62). Manual - part 165

SYSTEM

BRC-145

< SYSTEM DESCRIPTION >

[BRAKE ASSIST (WITH PREVIEW FUNCTION)]

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SYSTEM

BRAKE ASSIST (WITH PREVIEW FUNCTION)

BRAKE ASSIST (WITH PREVIEW FUNCTION) : System Description

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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 operation and is not a collision warning or avoidance
device. It is the driver

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s responsibility to stay alert, drive safely and be in control of the vehicle at all

times.

OPERATION DESCRIPTION

• The system detects the distance to the vehicle in front with the ICC sensor of ICC and judges the necessity

of emergency braking. 

• The system detects the accelerator pedal release operation 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 necessary 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 approximately 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 accelerator pedal or the brake pedal.

2.

If the driver does not operate the accelerator pedal or brake pedal within approximately 1 second.

BRC-146

< DTC/CIRCUIT DIAGNOSIS >

[BRAKE ASSIST (WITH PREVIEW FUNCTION)]

BRAKE ASSIST (WITH PREVIEW FUNCTION)

DTC/CIRCUIT DIAGNOSIS

BRAKE ASSIST (WITH PREVIEW FUNCTION)

Diagnosis Procedure

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PREVIEW FUNCTION DIAGNOSIS

When the preview function is not operating properly, the buzzer sounds and the preview function warning lamp
will come on. 
NOTE:
The preview function warning lamp shares the ICC system warning lamp.

>> Go to ICC. Refer to 

CCS-69, "Work Flow"

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NORMAL OPERATING CONDITION

BRC-147

< SYMPTOM DIAGNOSIS >

[BRAKE ASSIST (WITH PREVIEW FUNCTION)]

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SYMPTOM DIAGNOSIS

NORMAL OPERATING CONDITION

Description

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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

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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 System 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 temporarily 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 temporarily 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

BRC-148

< PRECAUTION >

[INTELLIGENT BRAKE ASSIST]

PRECAUTIONS

PRECAUTION

PRECAUTIONS

Precautions for IBA System Service

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CAUTION:

• Never look straight into the laser beam discharger when adjusting laser beam aiming.
• Never use the ICC sensor removed from vehicle. Never disassemble or remodel.
• Erase DTC when replacing parts of ICC system. Then check the operation of ICC system after adjust-

ing laser beam aiming if necessary.

• Never change IBA system state ON/OFF without the consent of the customer.
NOTE:
IBA system automatically returns to ON, when erasing self-diagnosis result of “ICC/ADAS” with CONSULT-III.