Engine control INFINITI Q50 2019 Repair Manual

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.
Starting and driving5-133
VEHICLE DYNAMIC CONTROL
(VDC) SYSTEM

5-134Starting and driving
.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.2-15).
If a malfunction occurs in the system, the
VDC warning light
illuminates in the
instrument panel. The VDC system automa-
tically 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
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.2-15) and “Vehicle Dynamic
Control (VDC) off indicator light” (P.2-18).
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.
VDC operation is reduced when the INFINITI
Drive Mode Selector is used to select the
SPORT+ mode (if so equipped). The VDC
system may not operate in the same circum-
stances when compared to operation in the
standard mode. To help prevent accidents
drive carefully, avoid careless or dangerous
driving techniques and be especially careful
when driving and cornering on slippery
surfaces.
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 driving condition. Always drive
carefully and attentively.
. 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,
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 extre-
mely deteriorated, the VDC system
may not operate properly and the
VDC warning light
may illumi-
nate.
. If engine control related parts are not
INFINITI recommended or are extre-
mely deteriorated, the VDC warning
light
may illuminate.

.When driving on extremely inclined
surfaces such as higher banked cor-
ners, the VDC system may not oper-
ate properly 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 oper-
ate properly and the VDC warning
light
may illuminate.
. The VDC system is not a substitute
for winter tires or tire chains on a
snow covered road. 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.5-22).
When the VDC OFF switch is used to turn
off the VDC system, the active trace control
is also turned off.
Starting and driving5-135
ACTIVE TRACE CONTROL

5-138Starting and driving
The Idling Stop System activates to prevent
unnecessary fuel consumption, exhaust
emissions and noise.
.When you fully depress the brake pedal
to stop the vehicle, the engine is turned
off automatically.
. When you release the brake pedal to
begin moving again, the engine is turned
on automatically.
WARNING
The engine restarts if the vehicle moves
at approximately 1 MPH (2 km/h) or
more (on a downhill grade, etc.), while
the engine is turned off by the Idling
Stop System. Depress the brake pedal
immediately to stop the vehicle to pre-
vent an accident.
CAUTION
At the end of the journey the engine
must be stopped and ignition switch be
turned off. Lock the vehicle as normal.
Turning the ignition switch OFF will shut
down all electrical systems. Failure to do
this may result in a discharged battery. NOTE:
The Idling Stop System will not activate
under the following conditions:
.
when the engine is kept idling without
the vehicle being driven after the engine
is turned on.
. when the engine coolant temperature is
low.
. when the battery capacity is low.
. when the battery temperature is low or
extremely high.
. when the vehicle is moving.
. when a negative pressure booster de-
creases.
. when the engine hood is opened with the
engine running.
. when the engine is turned on with the
engine hood open.
. when the driver’s seat belt is not fas-
tened.
. when the driver’s door is open.
. when the steering wheel is operated.
. when the angle of steering wheel is not
straight.
. when the Idling Stop System indicator
blinks at a low speed.
. when the fan speed control is in any
position other than “OFF” (0) while the
air flow control is in the front defroster
position. .
when the front defroster switch is on.
. when the rear window defroster switch
is on.
. When the temperature inside the vehicle
is lower than approximately 68°F
(20°C).
. When the temperature inside the vehicle
is higher than approximately 86°F
(30°C). (When the air conditioner is
off, the Idling Stop System will operate.)
. When the fan speed of the air condi-
tioner is set to the maximum speed.
. when the Idling Stop OFF switch is
turned on.
. when the power consumption is large.
. when the vehicle is traveling at altitudes
higher than 8,203 ft (2,500 m).
. when the accelerator pedal is depressed.
. when the shift lever is in the R (Reverse)
position.
. when the brake pedal is not firmly
depressed.
. when stopping the vehicle on steep
sloping roads.
NOTE:
The engine will not restart even if the brake
pedal is released while the Idling Stop
System is activated when the shift lever is
in the P (Park) position.
IDLING STOP SYSTEM (if so equipped)

NOTE:
It may take some time until the Idling Stop
System activates under the following con-
ditions:
.when the battery is discharged.
. when the outside temperature is low or
high.
. when the battery is replaced or the
battery terminal is disconnected for
extended periods and then reconnected.
NOTE:
When the Idling Stop System indicator light
illuminates, the engine starts running auto-
matically under at least one of the following
conditions:
. The brake pedal is released with the shift
lever in the D (Drive) or N (Neutral)
position.
. The shift lever is placed in the D (Drive)
or R (Reverse) position from the N
(Neutral) or P (Park) position.
. The driver’s seat belt is unfastened, or
the driver’s door is open.
. The battery voltage becomes low (due to
electrical load from other vehicle sys-
tems like headlights, heaters, etc., or
auxiliary devices connected to the 12
volt socket inside the vehicle).
. The vehicle speed is above about 1 MPH
(2 km/h). .
The front defroster is operated.
. The rear window defroster is operated.
. When the temperature inside the vehicle
is lower than approximately 68°F
(20°C).
. When the temperature inside the vehicle
is higher than approximately 86°F
(30°C). (When the air conditioner is
off, the Idling Stop System will operate.)
. When the front defroster is turned on.
(The engine may not starts depending
on the outside temperature.)
. When more than 3 minutes have elapsed
since the Idling Stop System was active.
. When the accelerator pedal is depressed.
. When the steering wheel is operated.
(The steering wheel operation may be-
come heavy, but this is not a malfunc-
tion.)
. When the battery capacity is low.
. When the power consumption is high.
. When the shift lever is placed in the R
(Reverse) position.
NOTE:
The following condition will prevent the
Idling Stop System from automatically re-
starting the engine. Starting the engine
with the ignition switch operation is then
necessary: .
The hood is open.
Use this system while waiting at stoplight,
etc. When the vehicle is stopped for long
periods of time, turn off the engine.
When the engine is stopped by the Idling
Stop System, heating, cooling and dehumi-
difying functions will be deactivated. To
avoid the air conditioning functions from
being deactivated, turn off the Idling Stop
mode by pushing the Idling Stop OFF switch.
RETROGRADE MOVEMENT
CONTROL FUNCTION
This system is designed to reduce the retro-
grade movement that occurs while the
driver’s foot changes from depressing the
brake pedal to the accelerator pedal when
moving the vehicle while the Idling Stop
System is active on a hilly road.
IDLING STOP SYSTEM DISPLAY
The status of the Idling Stop System can be
checked in the vehicle information display.
Starting and driving5-139

Intelligent All-Wheel Drive (AWD)
models
If you install snow tires, they must also be
the same size, brand, construction and 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 (32°F, 0°C 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
caution. Accelerate and slow down
with care. If accelerating or down-
shifting 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 pave-
ment.
. 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 steer-
ing 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 20°F
(−7°C) 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 driving5-143

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.8-40).
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.8-40).)
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.

6-16In case of emergency
Do not attempt to start the engine by
pushing.
CAUTION
.Automatic Transmission (AT) models
cannot be push-started or tow-
started. Attempting to do so may
cause transmission damage.
. Three-way catalyst equipped models
should not be started by pushing
since the three-way catalyst may be
damaged.
. Never try to start the vehicle by
towing it; when the engine starts,
the forward surge could cause the
vehicle to collide with the tow vehi-
cle.
CAUTION
.Do not continue to drive if your
vehicle overheats. Doing so could
cause engine damage or a vehicle fire.
. To avoid the danger of being scalded,
never remove the radiator cap while
the engine is still hot. When the
radiator cap is removed, pressurized
hot water will spurt out, possibly
causing serious injury.
. Do not open the hood if steam is
coming out.
If your vehicle is overheating (indicated by an
extremely high temperature gauge reading),
or if you feel a lack of engine power, detect
abnormal noise, etc., take the following
steps:
1. Move the vehicle safely off the road, apply the parking brake and move the
shift lever to the P (Park) position.
Do not stop the engine.
2. Turn off the climate control. Open all the windows, move the heater or air condi-
tioner temperature control to maximum
hot and fan control to high speed.
3. If engine overheating is caused by climb- ing a long hill on a hot day, run 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
PUSH STARTING IF YOUR VEHICLE OVERHEATS

8 Do-it-yourself
Maintenance precautions ............................................... 8-3
Engine compartment check locations ......................... 8-4VR30DDTT engine ..................................................... 8-4
2.0L turbo gasoline engine ...................................... 8-5
Engine cooling system (for VR30DDTT
engine models) ................................................................... 8-6
Checking engine coolant level ................................ 8-7
Changing engine coolant .......................................... 8-7
Engine cooling system (for 2.0L turbo gasoline
engine models) ................................................................... 8-8
Checking engine coolant level ................................. 8-8
Changing engine coolant .......................................... 8-9
Intercooler cooling system (for VR30DDTT
engine models) ................................................................... 8-9 Checking intercooler coolant level ...................... 8-10
Changing intercooler coolant ............................... 8-10
Engine oil ........................................................................\
.. 8-10 Checking engine oil level ......................................... 8-11
Changing engine oil and filter ................................ 8-11
Automatic Transmission Fluid (ATF) ........................ 8-14
Power steering fluid (models with hydraulic pump
electric power steering) ................................................ 8-14
Brake fluid ........................................................................\
. 8-15
Window washer fluid .................................................... 8-15 Battery ........................................................................\
...... 8-16
Main battery location ............................................ 8-17
Auxiliary battery location (for 2.0L turbo
gasoline engine models) ........................................ 8-17
Checking battery fluid level .................................. 8-18
Jump starting ........................................................... 8-19
Variable voltage control system ................................ 8-19
Drive belts ........................................................................\
8-19
Spark plugs ..................................................................... 8-20 Replacing spark plugs ............................................ 8-21
Air cleaner ........................................................................\
8-21
Windshield wiper blades .............................................. 8-22 Cleaning ..................................................................... 8-22
Replacing ................................................................... 8-22
Brakes ........................................................................\
........ 8-23 Self-adjusting brakes ............................................. 8-23
Brake pad wear warning ....................................... 8-23
Fuses ........................................................................\
.......... 8-23 Engine compartment ............................................. 8-24
Passenger compartment ....................................... 8-25
Intelligent Key battery replacement ......................... 8-26
Lights ........................................................................\
......... 8-29 Headlights ................................................................. 8-29
Exterior and interior lights ................................... 8-30

JUMP STARTING
If jump starting is necessary, see “Jump
starting” (P.6-9). If the engine does not start
by jump starting, the battery may have to be
replaced. It is recommended you visit an
INFINITI retailer for this service.CAUTION
.Do not ground accessories directly to
the battery terminal. Doing so will
bypass the variable voltage control
system and the vehicle battery may
not charge completely.
. Use electrical accessories with the
engine running to avoid discharging
the vehicle battery.
The variable voltage control system mea-
sures the amount of electrical discharge
from the battery and controls voltage gen-
erated by the generator.
JVM0655X
VR30DDTT engine
1. Water pump
2. Alternator
3. Drive belt auto-tensioner
4. Crankshaft pulley
5. Air conditioner compressor
Do-it-yourself8-19
VARIABLE VOLTAGE CONTROL SYSTEMDRIVE BELTS