service INFINITI Q50 2018 Workshop Manual

5-128Starting and driving
the vehicle, but the steering will be much
harder to operate.
The hydraulic pump electric power steering
is designed to provide power assistance
while driving to operate the steering wheel
with light force.
When the steering wheel is operated re-
peatedly or continuously while parking or
driving at a very low speed, the power assist
for the steering wheel will be reduced. This is
to prevent overheating of the hydraulic
pump electric power steering and protect it
from getting damaged. While the power
assist is reduced, steering wheel operation
will become heavy. If the steering wheel
operation is still performed, the power
steering may stop and the power steering
warning light will illuminate. Stop the engine
and place the ignition switch in the OFF
position. The temperature of the hydraulic
pump electric power steering will go down
and the power assist level will return to
normal after starting the engine. The power
steering warning light will go off. Avoid
repeating such steering wheel operations
that could cause the hydraulic pump electric
power steering to overheat.
You may hear a noise from the front of the
vehicle when the steering wheel is operated.
This is not a malfunction. If the power steering warning light illumi-
nates while the engine is running, it may
indicate the hydraulic pump electric power
steering is not functioning properly and may
need servicing. It is recommended you have
the hydraulic pump electric power steering
checked by an INFINITI retailer.
When the power steering warning light
illuminates with the engine running, the
power assist for the steering will cease
operation but you will still have control of
the vehicle. At this time, greater steering
efforts are required to operate the steering
wheel, especially in sharp turns and at low
speeds.
DIRECT ADAPTIVE STEERING
TYPE
WARNING
.
When the power steering warning
light illuminates with the engine run-
ning, the power assist for the steer-
ing will cease operation. You will still
have control of the vehicle, but the
steering will be harder to operate.
. If wheels or tires other than the
INFINITI recommended ones are
used, Direct Adaptive Steering may
not operate properly and the power steering warning light may illumi-
nate.
. Do not modify the vehicle’s suspen-
sion. If suspension parts such as
shock absorbers, struts, springs, sta-
bilizer bars, bushings and wheels are
not INFINITI recommended for your
vehicle or are extremely deteriorated,
Direct Adaptive Steering may not
operate properly and the power
steering warning light may illumi-
nate.
. Do not modify the vehicle’s steering.
If steering parts are not INFINITI
recommended for your vehicle or are
extremely deteriorated, Direct Adap-
tive Steering may not operate prop-
erly and the power steering warning
light may illuminate.
. If the VDC warning light illuminates,
the power steering warning light may
also illuminate at the same time. Stop
the vehicle in a safe location, turn the
engine off and restart the engine. If
the power steering warning light
continues to illuminate, have the
system checked. It is recommended
you visit an INFINITI retailer for this
service. For VDC system, see “Vehicle
Dynamic Control (VDC) system”
(P.5-132).

5-130Starting and driving
a straight road for a period of time.
. After the engine is started, the steering
wheel may move if the steering wheel
was turned to the fully locked position
while the ignition switch was in the OFF
position.
. After the vehicle is tested on the 4-wheel
dynamometer, the steering wheel may
turn slightly even when driving on a
straight road. To return the steering
wheel to the normal position, drive the
vehicle on a straight road for a period of
time.
You may hear a noise under the following
conditions. However, this is not a malfunc-
tion.
. When the engine is started or stopped.
. When the steering wheel is turned in the
full lock position.BRAKING PRECAUTIONS
The brake system has two separate hydrau-
lic 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 pressure 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
accelerating 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 perfor-
mance.
This procedure is described in the vehicle
service manual. It is recommended you visit
BRAKE SYSTEM

an INFINITI retailer for this service.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 prevent accidents resulting
from careless or dangerous driving
techniques. It can help maintain ve-
hicle control during braking on slip-
pery surfaces. Remember that
stopping distances on slippery sur- faces will be longer than on normal
surfaces even with ABS. Stopping
distances 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 la-
bel” (P.10-16) of this manual.
— For detailed information, see “Wheels and tires” (P.8-32) of
this manual.
The Anti-lock Braking System (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
Starting and driving5-131
BRAKE ASSIST

5-132Starting and driving
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 dis-
tances.
Self-test feature
The 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 mal-function, 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. It is recommended you visit
an INFINITI retailer for this service.
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 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
properly. However, the pulsation may indi-
cate 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 out-
put 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 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 conditions).
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.
VEHICLE DYNAMIC CONTROL
(VDC) SYSTEM

6-2In case of emergency
SIC2574
Push the switch on to warn other drivers
when you must stop or park under emer-
gency conditions. All turn signal lights will
flash.
WARNING
.If stopping for an emergency, be sure
to move the vehicle well off the road.
. Do not use the hazard warning
flashers while moving on the highway
unless unusual circumstances force
you to drive so slowly that your
vehicle might become a hazard to
other traffic. .
Turn signals do not work when the
hazard warning flasher lights are on.
The flasher can be actuated with the ignition
switch in any position.
When an impact that could activate the
supplemental air bags is detected, the
hazard warning flasher lights blink automa-
tically. If the hazard warning flasher switch is
pushed, the hazard warning flashers will turn
off.
WARNING
Do not turn the hazard warning flasher
switch to off until you can make sure
that it is safe to do so. Also, the hazard
flasher warning may not blink automa-
tically depending on the force of impact.
Some state laws may prohibit the use of the
hazard warning flasher switch while driving. In the event of a roadside emergency,
Roadside Assistance Service is available to
you. Please refer to your Warranty Informa-
tion Booklet (U.S.) or Warranty & Roadside
Assistance Information Booklet (Canada) for
details.
HAZARD WARNING FLASHER SWITCHROADSIDE ASSISTANCE PROGRAM

6-4In case of emergency
is recommended you visit an INFINITI
retailer for these services.
. Replacing tires with those not origin-
ally specified by INFINITI could affect
the 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 pres-
sure sensors.
RUN-FLAT TIRES (if so equipped)
Run-flat tires are those tires that can be
used temporarily if they are punctured. See
“Run-flat tires” (P.8-39).
Also, refer to “Important Tire Safety Infor-
mation” (US) or “Tire Safety Information”
(Canada) in the INFINITI Warranty Informa-
tion Booklet.
WARNING
.Although you can continue driving
with a punctured run-flat tire, re-
member that vehicle handling stabi-
lity 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 distance 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 punc-
tured 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 punctu-
red 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.
. It is recommended you 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 instructions
in this section to replace the tire with a spare
tire (if so equipped). For the vehicles with
run-flat tires, you can continue driving to a
safe location even if they are punctured. (See
“Run-flat tires” (P.6-4) and “Run-flat tires”
(P.8-39).)
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.

at a fast idle (approximately 1,500 rpm)
until the temperature gauge indication
returns to normal.
4. Get out of the vehicle. Look and listen for steam or coolant escaping from the
radiator before opening the hood. (If
steam or coolant is escaping, turn off the
engine.) Do not open the hood further
until no steam or coolant can be seen.
5. Open the engine hood.
WARNING
If steam or water is coming from the
engine, stand clear to prevent getting
burned.
6. Visually check drive belts for damage or looseness. Also check if the cooling fan is
running. The radiator hoses and radiator
should not leak water. If coolant is
leaking or the cooling fan does not run,
stop the engine.
WARNING
Be careful not to allow your hands, hair,
jewelry or clothing to come into contact
with, or get caught in, engine belts or the
engine cooling fan. The engine cooling fan can start at any time.
7. After the engine cools down, check the coolant level in the reservoir tank with
the engine running. Add coolant to the
reservoir tank if necessary. Have your
vehicle repaired. It is recommended you
visit an INFINITI retailer for this service. When towing your vehicle, all State (Pro-
vincial in Canada) and local regulations for
towing must be followed. Incorrect towing
equipment could damage your vehicle. Tow-
ing instructions are available from an
INFINITI retailer. Local service operators
are familiar with the applicable laws and
procedures for towing. To assure proper
towing and to prevent accidental damage to
your vehicle, INFINITI recommends that you
have a service operator tow your vehicle. It is
advisable to have the service operator care-
fully read the following precautions.
WARNING
.
Never ride in a vehicle that is being
towed.
. Never get under your vehicle after it
has been lifted by a tow truck.
CAUTION
.When towing, make sure that the
transmission, axles, steering system
and powertrain are in working con-
dition. If any unit is damaged, dollies
must be used.
. Always attach safety chains before
In case of emergency6-17
TOWING YOUR VEHICLE

6-20In case of emergency
designed specifically for vehicle recovery.
Always follow the manufacturer’s instruc-
tions for the recovery device.
Rocking a stuck vehicle
If your vehicle is stuck in sand, snow, mud,
etc., use the following procedure:
1. Turn off the Vehicle Dynamic Control(VDC) system.
2. Make sure the area in front and behind the vehicle is clear of obstructions.
3. Turn the steering wheel right and left to clear an area around the front tires.
4. Slowly rock the vehicle forward and backward.
.Shift back and forth between R (Re-verse) and D (Drive).
.Apply the accelerator as little aspossible to maintain the rocking mo-
tion.
.Release the accelerator pedal before shifting between R and D.
.Do not spin the tires above 35 MPH(55 km/h).
5. If the vehicle cannot be freed after a few tries, contact a professional towing
service to remove the vehicle.
WARNING
.Stand clear of a stuck vehicle.
. Do not spin your tires at high speed.
This could cause them to explode and
result in serious injury. Parts of your
vehicle could also overheat and be
damaged.

When performing any inspection or main-
tenance work on your vehicle, always take
care to prevent serious accidental injury to
yourself or damage to the vehicle. The
following are general precautions which
should be closely observed.
WARNING
.Park the vehicle on a level surface,
apply the parking brake securely and
block the wheels to prevent the
vehicle from moving. Move the shift
lever to P (Park).
. Be sure the ignition switch is in the
OFF or LOCK position when per-
forming any parts replacement or
repairs.
. Never connect or disconnect the
battery or any transistorized compo-
nent while the ignition switch is in the
ON position.
. Never leave the engine or automatic
transmission related component har-
nesses disconnected while the igni-
tion switch is in the ON position.
. If you must work with the engine
running, keep your hands, clothing,
hair and tools away from moving
fans, belts and any other moving parts.
. It is advisable to secure or remove
any loose clothing and remove any
jewelry, such as rings, watches, etc.
before working on your vehicle.
. Always wear eye protection when-
ever you work on your vehicle.
. If you must run the engine in an
enclosed space such as a garage, be
sure there is proper ventilation for
exhaust gases to escape.
. Never get under the vehicle while it is
supported only by a jack. If it is
necessary to work under the vehicle,
support it with safety stands.
. Keep smoking materials, flame and
sparks away from fuel tank and the
battery.
. Your vehicle is equipped with an
automatic engine cooling fan. It may
come on at any time without warn-
ing, even if the ignition key is in the
OFF position and the engine is not
running. To avoid injury, always dis-
connect the negative battery cable
before working near the fan.
. Because the fuel lines are under high
pressure even when the engine is off,
it is recommended you visit an
INFINITI retailer for service of the fuel filter or fuel lines.
CAUTION
.
Do not work under the hood while the
engine is hot. Turn the engine off and
wait until it cools down.
. Avoid direct contact with used en-
gine oil and coolant. Improperly dis-
posed engine oil, coolant, and/or
other vehicle fluids can damage the
environment. Always conform to lo-
cal regulations for disposal of vehicle
fluid.
This “8. Do-it-yourself” section gives in-
structions regarding only those items which
are relatively easy for an owner to perform.
A genuine INFINITI Service Manual is also
available. (See “Owner’s Manual/Service
Manual order information” (P.10-26).)
You should be aware that incomplete or
improper servicing may result in operating
difficulties or excessive emissions, and could
affect your warranty coverage. If in doubt
about any servicing, it is recommended you
have it done by an INFINITI retailer.
Do-it-yourself8-3
MAINTENANCE PRECAUTIONS

JVM0652X
CHECKING ENGINE COOLANT
LEVEL
Check the coolant level in the reservoir tank
when the engine is running and after it
reaches normal operating temperature. If
the coolant level is below MIN level
, add
coolant up to the MAX level. If the
reservoir tank is empty, check the coolant
level in the radiator when the engine is cold.
If there is insufficient coolant in the radiator,
fill the radiator with coolant up to the filler
cap above the radiator upper hose opening
and also add it to the reservoir tank up to the
MAX level
. Put on the filler cap above the
radiator upper hose and with the reservoir
cap open, start the engine. Run the engine until it reaches normal operating tempera-
ture. Add coolant up to the MAX level
.
Tighten the cap securely after adding engine
coolant.
If the cooling system requires coolant fre-
quently, have it checked. It is recommended
you visit an INFINITI retailer for this
service.
CHANGING ENGINE COOLANT
It is recommended that major cooling system
repairs be performed by an INFINITI retailer.
The service procedures can be found in the
appropriate INFINITI Service Manual.
Improper servicing can result in reduced
heater performance and engine overheat-
ing.
WARNING
. To avoid the danger of being scalded,
never change the coolant when the
engine is hot.
. Never remove the radiator cap when
the engine is hot. Serious burns could
be caused by high pressure fluid
escaping from the radiator.
. Avoid direct skin contact with used
coolant. If skin contact is made, wash
thoroughly with soap or hand cleaner as soon as possible.
. Keep coolant out of reach of children
and pets.
Engine coolant must be disposed of prop-
erly. Check your local regulations.
Do-it-yourself8-7