2021 INFINITI QX50 brake

The brake system has two separate hydraulic
circuits. If one circuit malfunctions, you will
still have braking at two wheels.
BRAKE PRECAUTIONS
Vacuum assisted brakes
The brake booster aids braking by using en-
gine vacuum. If the engine stops, you can
stop the vehicle by depressing the brake
pedal. However, greater foot pressure on the
brake pedal will be required to stop the ve-
hicle and stopping distance will be longer.
Using the brakes
Avoid resting your foot on the brake pedal
while driving. This will overheat the brakes,
wear out the brake pads faster, and reduce
gas mileage.
To help reduce brake wear and to prevent the
brakes from overheating, reduce speed and
downshift to a lower gear before going down
a slope or long grade. Overheated brakes
may reduce braking performance and could
result in loss of vehicle control.
WARNING
• While driving on a slippery surface, be
careful when braking, accelerating or
downshifting. Abrupt braking or accel-
erating could cause the wheels to skid
and result in an accident.
• If the engine is not running or is turned
off while driving, the power assist for the
brakes will not work. Braking will be
harder.
Wet brakes
When the vehicle is washed or driven through
water, the brakes may get wet. As a result,
your braking distance will be longer and the
vehicle may pull to one side during braking.
To dry the brakes, drive the vehicle at a safe
speed while lightly pressing the brake pedal to
heat up the brakes. Do this until the brakes
return to normal. Avoid driving the vehicle at
high speeds until the brakes function correctly.
Parking brake break-in
Break in the parking brake shoes whenever
the stopping effect of the parking brake is
weakened or whenever the parking brake
shoes and/or rotors are replaced, in order to
assure the best brake performance. This procedure is described in the INFINITI
Service Manual. It is recommended that you
visit an INFINITI retailer for this service.
ANTI-LOCK BRAKING SYSTEM
(ABS)
WARNING
• The ABS is a sophisticated device, but it
cannot prevent accidents resulting from
careless or dangerous driving tech-
niques. It can help maintain vehicle con-
trol during braking on slippery surfaces.
Remember that stopping distances on
slippery surfaces will be longer than on
normal surfaces even with ABS. Stop-
ping distances may also be longer on
rough, gravel or snow covered roads, or
if you are using tire chains. Always main-
tain a safe distance from the vehicle in
front of you. Ultimately, the driver is re-
sponsible for safety.
• Tire type and condition may also affect
braking effectiveness.
– When replacing tires, install the
specified size of tires on all four
wheels.
BRAKE SYSTEM
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–When installing a spare tire, make
sure that it is the proper size and type
as specified on the Tire and Loading
Information label. For additional in-
formation, see “Tire and Loading In-
formation label” (P. 8-28).
– For additional information, see
“Wheels and tires” (P. 8-27).
The ABS controls the brakes so the wheels do
not lock during hard braking or when braking
on slippery surfaces. The system detects the
rotation speed at each wheel and varies the
brake fluid pressure to prevent each wheel
from locking and sliding. By preventing each
wheel from locking, the system helps the
driver maintain steering control and helps to
minimize swerving and spinning on slippery
surfaces.
Using the system
Depress the brake pedal and hold it down.
Depress the brake pedal with firm steady
pressure, but do not pump the brakes. The
Anti-lock Braking System will operate to pre-
vent the wheels from locking up. Steer the
vehicle to avoid obstacles.
WARNING
Do not pump the brake pedal. Doing so may
result in increased stopping distances.
Self-test feature
The Anti-lock Braking System (ABS) includes
electronic sensors, electric pumps, hydraulic
solenoids and a computer. The computer has
a built-in diagnostic feature that tests the
system each time you start the engine and
move the vehicle at a low speed in forward or
reverse. When the self-test occurs, you may
hear a “clunk” noise and/or feel a pulsation in
the brake pedal. This is normal and does not
indicate a malfunction. If the computer
senses a malfunction, it switches the ABS off
and illuminates the ABS warning light on the
instrument panel. The brake system then op-
erates normally but without anti-lock
assistance.
If the ABS warning light illuminates during
the self-test or while driving, have the vehicle
checked. It is recommended that you visit an
INFINITI retailer for this service.
Normal operation
The Anti-lock Braking System (ABS) operates
at speeds above3-6mph(5-10km/h). The
speed varies according to road conditions.
When the ABS senses that one or more
wheels are close to locking up, the actuator
rapidly applies and releases hydraulic pres-
sure. This action is similar to pumping the
brakes very quickly. You may feel a pulsation
in the brake pedal and hear a noise from
under the hood or feel a vibration from the
actuator when it is operating. This is normal
and indicates that the ABS is operating prop-
erly. However, the pulsation may indicate
that road conditions are hazardous and extra
care is required while driving.
BRAKE ASSIST
When the force applied to the brake pedal
exceeds a certain level, the Brake Assist is
activated generating greater braking force
than a conventional brake booster even with
light pedal force.
Starting and driving5-153

WARNING
The Brake Assist is only an aid to assist
braking operation and is not a collision
warning or avoidance device. It is the driv-
er’s responsibility to stay alert, drive safely
and be in control of the vehicle at all times. The VDC system uses various sensors to
monitor driver inputs and vehicle motion. Un-
der certain driving conditions, the VDC sys-
tem helps to perform the following functions:
• Controls brake pressure to reduce wheel
slip on one slipping drive wheel so power is
transferred to a non-slipping drive wheel
on the same axle.
• Controls brake pressure and engine output to reduce drive wheel slip based on vehicle
speed (traction control function).
• Controls brake pressure at individual wheels and engine output to help the driver
maintain control of the vehicle in the fol-
lowing conditions:
Understeer (vehicle tends to not follow the
steered path despite increased steering input)
Oversteer (vehicle tends to spin due to certain
road or driving conditions)
The VDC system can help the driver to main-
tain control of the vehicle, but it cannot pre-
vent loss of vehicle control in all driving
situations.
When the VDC system operates, the
indicator light in the instrument panel flashes
to note the following:
• The road may be slippery or the system may determine some action is required to help
keep the vehicle on the steered path. • You may feel a pulsation in the brake pedal
and hear a noise or vibration from under the
hood. This is normal and indicates that the
VDC system is working properly.
• Adjust your speed and driving to the road conditions.
For additional information, see “Slip indicator
light” (P. 2-16) and ”Vehicle Dynamic Control
(VDC) OFF indicator light” (P. 2-17).
If a malfunction occurs in the system, the
andindicator lights come on in the
instrument panel. The VDC system automati-
cally turns off when these indicator lights are
on.
The lower display is used to turn off the VDC
system. When the VDC system is turned off,
the
indicator light, the RAB system
warning light, and the FEB with Pedestrian
Detection system warning light illuminate to
indicate the VDC, FEB with Pedestrian De-
tection, and RAB systems are off.
When the lower display is used to turn off the
system, the VDC system still operates to pre-
vent one drive wheel from slipping by trans-
ferring power to a non-slipping drive wheel.
The
indicator light flashes if this occurs.
All other VDC functions are off and the
indicator light will not flash.
VEHICLE DYNAMIC CONTROL (VDC)
SYSTEM
5-154Starting and driving

The VDC system is automatically reset to on
when the ignition switch is placed in the OFF
position then back to the ON position.
The computer has a built-in diagnostic fea-
ture that tests the system each time you start
the engine and move the vehicle forward or in
reverse at a slow speed. When the self-test
occurs, you may hear a clunk noise and/or
feel a pulsation in the brake pedal. This is
normal and is not an indication of a
malfunction.
WARNING
• The VDC system is designed to help the
driver maintain controllability but does
not prevent accidents due to abrupt
steering operation at high speeds or by
careless or dangerous driving tech-
niques. Reduce vehicle speed and be es-
pecially careful when driving and corner-
ing on slippery surfaces and always drive
carefully. •
Do not modify the vehicle's suspension.
If suspension parts such as shock ab-
sorbers, struts, springs, stabilizer bars,
bushings and wheels are not INFINITI
recommended for your vehicle or are ex-
tremely deteriorated, the VDC system
may not operate properly. This could ad-
versely affect vehicle handling perfor-
mance, and the
indicator light may
flash or both theandindicator
lights may illuminate.
• If brake related parts such as brake pads,
rotors and calipers are not INFINITI rec-
ommended or are extremely deterio-
rated, the VDC system may not operate
properly and both the
and theindicator lights may illuminate.
• If engine control related parts are not
INFINITI recommended or are extremely
deteriorated, both the
andindicator lights may illuminate.
• When driving on extremely inclined sur-
faces such as higher banked corners, the
VDC system may not operate properly
and the
indicator light may flash or
both theandindicator lights
may illuminate. Do not drive on these
types of roads. •
When driving on an unstable surface
such as a turntable, ferry, elevator or
ramp, the
indicator light may flash
or both theandindicator
lights may illuminate. This is not a mal-
function. Restart the engine after driv-
ing onto a stable surface.
• If wheels or tires other than the INFINITI
recommended ones are used, the VDC
system may not operate properly and
the
indicator light may flash or both
theandindicator lights may
illuminate.
• The VDC system is not a substitute for
winter tires or tire chains on a snow cov-
ered road.
BRAKE FORCE DISTRIBUTION
During braking while driving through turns,
the system optimizes the distribution of force
to each of the four wheels depending on the
radius of the turn.
Starting and driving5-155

WARNING
• The VDC system is designed to help the
driver maintain controllability but does
not prevent accidents due to abrupt
steering operation at high speeds or by
careless or dangerous driving tech-
niques. Reduce vehicle speed and be es-
pecially careful when driving and corner-
ing on slippery surfaces and always drive
carefully.
• Do not modify the vehicle’s suspension.
If suspension parts such as shock ab-
sorbers, struts, springs, stabilizer bars,
bushings and wheels are not INFINITI
recommended for your vehicle or are ex-
tremely deteriorated, the VDC system
may not operate properly. This could ad-
versely affect vehicle handling perfor-
mance, and the
indicator light may
flash or both theandindicator
lights may illuminate.
• If brake related parts such as brake pads,
rotors and calipers are not INFINITI rec-
ommended or are extremely deterio-
rated, the VDC system may not operate
properly and both the
and theindicator lights may illuminate. •
If engine control related parts are not
INFINITI recommended or are extremely
deteriorated, both the
andindicator lights may illuminate.
• When driving on extremely inclined sur-
faces such as higher banked corners, the
VDC system may not operate properly
and the
indicator light may flash or
both theandindicator lights
may illuminate. Do not drive on these
types of roads.
• When driving on an unstable surface
such as a turntable, ferry, elevator or
ramp, the
indicator light may flash
or both theandindicator
lights may illuminate. This is not a mal-
function. Restart the engine after driv-
ing onto a stable surface.
• If wheels or tires other than the INFINITI
recommended ones are used, the VDC
system may not operate properly and
the
indicator light may flash or both
theandindicator lights may
illuminate.
• The VDC system is not a substitute for
winter tires or tire chains on a snow cov-
ered road. The chassis control is an electric control mod-
ule that includes the following functions:
• Active Trace Control
• Active Engine Brake
• Active Ride Control
ACTIVE TRACE CONTROL
This system senses driving based on the driv-
er’s steering and acceleration/braking pat-
terns, and controls brake pressure at indi-
vidual wheels to help smooth vehicle
response.
When the lower display is used to turn off the
Vehicle Dynamic Control system, the Active
Trace Control system is also turned off.
The Active Trace Control can be set to on
(enabled) or off (disabled) through the lower
display “Drive Mode Selector” menu option.
CHASSIS CONTROL
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When the Active Trace Control is operated
and the “Chassis Control” mode is selected in
the vehicle information display, the Active
Trace Control graphics are shown in the ve-
hicle information display.
If the chassis control warning message ap-
pears in the vehicle information display, it
may indicate that the Active Trace Control is
not functioning properly. Have the system
checked as soon as possible by an INFINITI
dealer.WARNING
The Active Trace Control may not be effec-
tive depending on the driving condition. Al-
ways drive carefully and attentively.
When the Active Trace Control is operating,
you may feel a pulsation in the brake pedal
and hear a noise. This is normal and indicates
that the Active Trace Control is operating
properly.
You may also feel deceleration when the Ac-
tive Trace Control is operating. However, this
is not a malfunction. Even if the Active Trace Control is set to OFF,
some functions will remain on to assist the
driver (for example: avoidance scenes).
ACTIVE ENGINE BRAKE
The Active Engine Brake function adds subtle
deceleration by controlling Continuously
Variable Transmission (CVT) gear ratio, de-
pending on the cornering condition calcu-
lated from the driver's steering input and plu-
ral sensors. This benefit is for easier
traceability and less workload of adjusting
speed with braking at corners.
The Active Engine Brake also enhances brak-
ing feel by adding subtle deceleration with
CVT gear ratio control according to the driv-
er's brake pedal operation
The Active Engine Brake can be set to on
(enabled) or off (disabled) through the lower
display “Drive Mode Selector” menu option.
LSD2185
Starting and driving5-157

When the Active Engine Brake is operated at
corners and the “Chassis Control” mode is
selected in the vehicle information display,
the Active Engine Brake graphics are shown
in the vehicle information display.
If the chassis control warning message ap-
pears in the vehicle information display, it
may indicate that the Active Engine Brake is
not functioning properly. Have the system
checked as soon as possible. It is recom-
mended that you visit an INFINITI retailer for
this service.WARNING
The Active Engine Brake may not be effec-
tive depending on the driving condition. Al-
ways drive carefully and attentively.
When the Active Engine Brake is operating,
the needle of the tachometer will rise up and
you may hear an engine noise. This is normal
and indicates that the Active Engine Brake is
operating properly.
You may also feel deceleration when the Ac-
tive Engine Brake is operating. However, this
is not a malfunction.
ACTIVE RIDE CONTROL
This system senses upper body motion
(based on wheel speed information) and con-
trols four wheel brake pressure. This will en-
hance ride comfort in an effort to restrain
uncomfortable upper body movement when
passing over undulated road surfaces.
When the lower display is used to turn off the
VDC system, the Active Ride Control is also
turned off.
When the Active Ride Control is operated
and the “Chassis Control” mode is selected in
the vehicle information display, the Active
Ride Control graphics are shown in the ve-
hicle information display.
LSD2185
5-158Starting and driving

If the chassis control system error warning
message appears in the vehicle information
display, it may indicate that the Active Ride
Control is not functioning properly. Have the
system checked as soon as possible. It is rec-
ommended that you visit an INFINITI retailer
for this service.
When the Active Ride Control is operating,
you may hear noise and sense slight decel-
eration. This is normal and indicates that the
Active Ride Control is operating properly.
WARNING
• Never rely solely on the hill start assist
system to prevent the vehicle from mov-
ing backward on a hill. Always drive
carefully and attentively. Depress the
brake pedal when the vehicle is stopped
on a steep hill. Be especially careful when
stopped on a hill on frozen or muddy
roads. Failure to prevent the vehicle
from rolling backwards may result in a
loss of control of the vehicle and possible
serious injury or death.
• The hill start assist system is not de-
signed to hold the vehicle at a standstill
on a hill. Depress the brake pedal when
the vehicle is stopped on a steep hill. Fail-
ure to do so may cause the vehicle to roll
backwards and may result in a collision or
serious personal injury.
• The hill start assist system may not pre-
vent the vehicle from rolling backwards
on a hill under all load or road conditions.
Always be prepared to depress the brake
pedal to prevent the vehicle from rolling
backwards. Failure to do so may result in
a collision or serious personal injury. When the vehicle is stopped on a hill, the hill
start assist system automatically keeps the
brakes applied to help prevent the vehicle
from rolling backward in the time it takes the
driver to release the brake pedal and apply
the accelerator.
The hill start assist system will operate auto-
matically under the following conditions:
• The transmission is shifted to a forward or
reverse gear.
• The vehicle is stopped completely on a hill by applying the brake. The maximum hold-
ing time is 2 seconds. After 2 seconds the
vehicle will begin to roll back and the hill
start assist system will stop operating
completely.
The hill start assist system will not operate
when the shift lever is placed in the N (Neu-
tral), the Park button is pressed to place the
vehicle in the P (Park) position or on a flat and
level road.
The Hill Start Assist function status can be
checked in the “Chassis Control” mode in the
vehicle information display. For additional in-
formation, see “Vehicle information display”
(P. 2-19).
LSD3922
HILL START ASSIST SYSTEM
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