2014 INFINITI Q50 brake

5-106Starting and driving
BRAKING PRECAUTIONS
The brake system has two separate hy-
draulic circuits. If one circuit malfunctions,
you will still have braking at two wheels.
Vacuum assisted brakes
The brake booster aids braking by using
engine vacuum. If the engine stops, you
can stop the vehicle by depressing the
brake pedal. However, greater foot pres-
sure on the brake pedal will be required to
stop the vehicle and the stopping distance
will be longer.
Using the brakes
Avoid resting your foot on the brake pedal
while driving. This will cause overheating
of the brakes, wearing out the brake and
pads faster and reduce gas mileage.
To help save the brakes 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 brakes, drive the vehicle at a safe
speed while lightly tapping 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 drums/rotors are replaced,
in order to assure the best braking
performance.
This procedure is described in the vehicle
service manual and can be performed by
an INFINITI retailer.
BRAKE SYSTEM

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.
WARNING
The Brake Assist 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.
ANTI-LOCK BRAKING SYSTEM (ABS)
WARNING
.The Anti-lock Braking System (ABS) is a
sophisticated device, but it cannot pre-
vent accidents resulting from careless or
dangerous driving techniques. It can
help maintain vehicle control during
braking on slippery surfaces. Remember
that stopping distances on slippery
surfaces will be longer than on normal surfaces even with ABS. Stopping dis-
tances may also be longer on rough,
gravel or snow covered roads, or if you
are using tire chains. Always maintain a
safe distance from the vehicle in front of
you. Ultimately, the driver is responsible
for safety.
. Tire type and condition may also affect
braking effectiveness.
—When replacing tires, install the
specified size of tires on all four
wheels.
—When installing a spare tire, make sure that it is the proper size and
type as specified on the Tire and
Loading Information label. See “Tire
and loading information label” (P.9-
13) of this manual.
—For detailed information, see “Wheels and tires” (P.8-29) of this
manual.
The Anti-lock Braking System (ABS) con-
trols 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 pre-
venting 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
ABS will operate to prevent 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 ABS includes electronic sensors, elec-
tric 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 pulsa-
Starting and driving5-107
BRAKE ASSIST

5-108Starting and driving
tion 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 operates normally,
but without anti-lock assistance.
If the ABS warning light illuminates during
the self-test or while driving, have the
vehicle checked by an INFINITI retailer.
Normal operation
The ABS operates at speeds above 3 to 6
MPH (5 to 10 km/h).
When the ABS senses that one or more
wheels are close to locking up, the actuator
rapidly applies and releases hydraulic
pressure. 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 properly. How-
ever, the pulsation may indicate that road
conditions are hazardous and extra care is
required while driving.The Vehicle Dynamic Control (VDC) system
uses various sensors to monitor driver
inputs and vehicle motion. Under certain
driving conditions, the VDC system 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 func-
tion).
. Controls brake pressure at individual
wheels and engine output to help the
driver maintain control of the vehicle in
the following 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 condi-
tions).
The VDC system can help the driver to
maintain control of the vehicle, but it
cannot prevent loss of vehicle control in
all driving situations.
When the VDC system operates, the VDC
warning light
in the instrument panel flashes so 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.
See “Vehicle Dynamic Control (VDC) warn-
ing light” (P.2-17).
If a malfunction occurs in the system, the
VDC warning light
illuminates in the
instrument panel. The VDC system auto-
matically turns off.
The VDC OFF switch is used to turn off the
VDC system. The VDC off indicator light
illuminates to indicate the VDC system is
off. When the VDC switch is used to turn off
the system, the VDC system still operates
to prevent one drive wheel from slipping by
transferring power to a non slipping drive
wheel. The VDC warning light
flashes if
this occurs. All other VDC functions are off,
except for brake force distribution, and the
VDC warning light
will not flash. The
VEHICLE DYNAMIC CONTROL (VDC) SYSTEM

VDC system is automatically reset to on
when the ignition switch is placed in the off
position then back to the on position.
See“Vehicle Dynamic Control (VDC) warn-
ing light” (P.2-17) and “Vehicle Dynamic
Control (VDC) off indicator light” (P.2-19).
The computer has a built-in diagnostic
feature 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.
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.
WARNING
. The VDC system is designed to help the
driver maintain stability but does not
prevent accidents due to abrupt steering
operation at high speeds or by careless
or dangerous driving techniques. Reduce
vehicle speed and be especially careful when driving and cornering on slippery
surfaces and always drive carefully.
. The brake force distribution system may
not be effective depending on the driv-
ing condition. Always drive carefully and
attentively.
. Do not modify the vehicle’s suspension.
If suspension parts such as shock
absorbers, struts, springs, stabilizer
bars, bushings and wheels are not
INFINITI recommended for your vehicle
or are extremely deteriorated, the VDC
system may not operate properly. This
could adversely affect vehicle handling
performance, and the VDC warning light
may illuminate.
. If brake related parts such as brake
pads, rotors and calipers are not INFINITI
recommended or are extremely deterio-
rated, the VDC system may not operate
properly and the VDC warning light
may illuminate.
. If engine control related parts are not
INFINITI recommended or are extremely
deteriorated, the VDC warning light
may illuminate.
. When driving on extremely inclined
surfaces such as higher banked corners, the VDC system may not operate prop-
erly and the VDC warning light
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 VDC warning light
may
illuminate. This is not a malfunction.
Restart the engine after driving 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 VDC warning light
may illumi-
nate.
. The VDC system is not a substitute for
winter tires or tire chains on a snow
covered road.
Starting and driving5-109

5-110Starting and driving
This system senses driving based on the
driver’s steering and acceleration/braking
patterns, and controls brake pressure at
individual wheels to help smooth vehicle
response.
When the SPORT mode is selected by the
INFINITI Drive Mode Selector, the amount of
brake control provided by the active trace
control is reduced.
When the PERSONAL mode is selected, the
active trace control can be set to ON
(enabled) or OFF (disabled). See“INFINITI
Drive Mode Selector” (P.5-21).
When the VDC OFF switch is used to turn off
the VDC system, the active trace control is
also turned off.
JVS0249X
When the active trace control is operated
and the “Chassis Control” mode is selected
in the trip computer, the active trace
control graphics are shown in the vehicle
information display. (See “Trip computer”
(P.2-28).)
If the chassis control warning message
appears in the vehicle information display,
it may indicate that the active trace control
is not functioning properly. Have the
system checked by an INFINITI retailer.
(See “26. Chassis control warning” (P.2-
24).)
WARNING
The active trace control may not be effective
depending on the driving condition. Always
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.
Even if the active trace control is set to OFF,
some functions will remain on to assist the
ACTIVE TRACE CONTROL

driver (for example, avoidance scenes).WARNING
.Never rely solely on the hill start assist
system to prevent the vehicle from
moving 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
designed to hold the vehicle at a
standstill on a hill. Depress the brake
pedal when the vehicle is stopped on a
steep hill. Failure 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
prevent the vehicle from rolling back-
wards on a hill under all load or road
conditions. Always be prepared to de-
press the brake pedal to prevent the
vehicle from rolling backwards. Failure to
do so may result in a collision or serious
personal injury.
The hill start assist system automatically
keeps the brakes applied to help prevent
the vehicle from rolling backwards in the
time it takes the driver to release the brake
pedal and apply the accelerator when the
vehicle is stopped on a hill.
The hill start assist system will operate
automatically under the following condi-
tions:
.The transmission is shifted to a forward
or reverse gear.
. The vehicle is stopped completely on a
hill by applying the brake.
The maximum holding 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 transmission is shifted to the N
(Neutral) or P (Park) position or on a flat
and level road.
Starting and driving5-111
HILL START ASSIST SYSTEM

tread pattern on all four wheels.
SPECIAL WINTER EQUIPMENT
It is recommended that the following items
be carried in the vehicle during winter:
.A scraper and stiff-bristled brush to
remove ice and snow from the windows
and wiper blades.
. A sturdy, flat board to be placed under
the jack to give it firm support.
. A shovel to dig the vehicle out of
snowdrifts.
. Extra window washer fluid to refill the
reservoir tank.
DRIVING ON SNOW OR ICE
WARNING
. Wet ice (328F, 0 8C and freezing rain),
very cold snow or ice can be slick and
very hard to drive on. The vehicle will
have much less traction or “grip”under
these conditions. Try to avoid driving on
wet ice until the road is salted or
sanded.
. Whatever the condition, drive with cau-
tion. Accelerate and slow down with
care. If accelerating or downshifting too fast, the drive wheels will lose even
more traction.
. Allow more stopping distance under
these conditions. Braking should be
started sooner than on dry pavement.
. Allow greater following distances on
slippery roads.
. Watch for slippery spots (glare ice).
These may appear on an otherwise clear
road in shaded areas. If a patch of ice is
seen ahead, brake before reaching it. Try
not to brake while on the ice, and avoid
any sudden steering maneuvers.
. Do not use the cruise control on slippery
roads.
. Snow can trap dangerous exhaust gases
under your vehicle. Keep snow clear of
the exhaust pipe and from around your
vehicle.
ENGINE BLOCK HEATER (if so
equipped)
Engine block heaters are used to assist in
cold temperature starting.
The engine block heater should be used
when the outside temperature is 208 F
(−78C) or lower.
To use the engine block heater
1. Turn the engine off.
2. Open the hood and unwrap the engine block heater cord.
3. Plug the engine block heater cord into a grounded 3-wire, 3-pronged extension
cord.
4. Plug the extension cord into a Ground Fault Interrupt (GFI) protected,
grounded 110-volt AC (VAC) outlet.
5. The engine block heater must be plugged in for at least 2 - 4 hours,
depending on outside temperatures, to
properly warm the engine coolant. Use
an appropriate timer to turn the engine
block heater on.
6. Before starting the engine, unplug and properly store the cord to keep it away
from moving parts.
Starting and driving5-113

6-4In case of emergency
proper operation of the TPMS.
. Do not inject any tire liquid or aerosol
tire sealant into the tires, as this may
cause a malfunction of the tire pressure
sensors.
RUN-FLAT TIRES
Run-flat tires are those tires that can be
used temporarily if they are punctured. See
“Run-flat tires” (P.8-36).
Also, refer to “Important Tire Safety In-
formation” (US) or“Tire Safety Informa-
tion” (Canada) in the INFINITI Warranty
Information Booklet.
WARNING
. Although you can continue driving with a
punctured run-flat tire, remember that
vehicle handling stability is reduced,
which could lead to an accident and
personal injury. Also, driving a long
distance at high speeds may damage
the tires.
. Do not drive at speeds above 50 MPH
(80 km/h) and do not drive more than
approximately 93 miles (150 km) with a punctured run-flat tire. The actual dis-
tance the vehicle can be driven on a flat
tire depends on outside temperature,
vehicle load, road conditions and other
factors.
. Drive safely at reduced speeds. Avoid
hard cornering or braking, which may
cause you to lose control of the vehicle.
. If you detect any unusual sounds or
vibrations while driving with a punctured
run-flat tire, pull off the road to a safe
location and stop the vehicle as soon as
possible. The tire may be seriously
damaged and need to be replaced.
CAUTION
.Never install tire chains on a punctured
run-flat tire, as this could damage your
vehicle.
. Avoid driving over any projection or
pothole, as the clearance between the
vehicle and the ground is smaller than
normal.
. Do not enter an automated car wash with
a punctured run-flat tire. .
Have the punctured tire inspected by an
INFINITI retailer or other authorized
repair shop. Replace the tire as soon
as possible if the tire is seriously
damaged.
CHANGING A FLAT TIRE
If you have a flat tire, follow the instruc-
tions in this section to replace the tire with
a spare tire (if so equipped). For the
vehicles with run-flat tires, you can con-
tinue driving to a safe location even if they
are punctured. (See “Run-flat tires”(P.6-4)
and “Run-flat tires” (P.8-36).)
This section also contains the information
about the vehicle jack-up procedures.
Stopping the vehicle
1. Safely move the vehicle off the road and away from traffic.
2. Turn on the hazard warning flashers.
3. Park on a level surface and apply the parking brake. Move the shift lever to
the P (Park) position.
4. Turn off the engine.
5. Raise the hood to warn other traffic, and to signal professional road assis-