check engine light CADILLAC XTS 2018 User Guide

Cadillac XTS Owner Manual (GMNA-Localizing-U.S./Canada-11354412) -
2018 - crc - 11/16/17
134 INSTRUMENTS AND CONTROLS
When the Light Is On Steady
This indicates that one or more of the
tires are significantly underinflated.
A Driver Information Center (DIC) tire
pressure message may also display.
Stop as soon as possible, and inflate
the tires to the pressure value shown
on the Tire and Loading Information
label. SeeTire Pressure 0274.
When the Light Flashes First and
Then Is On Steady
If the light flashes for about a minute
and then stays on, there may be a
problem with the TPMS. If the
problem is not corrected, the light will
come on at every ignition cycle. See
Tire Pressure Monitor Operation 0277.
Engine Oil Pressure Light
Caution
Lack of proper engine oil
maintenance can damage the
engine. Driving with the engine oil
low can also damage the engine.
(Continued)
Caution (Continued)
The repairs would not be covered
by the vehicle warranty. Check the
oil level as soon as possible. Add oil
if required, but if the oil level is
within the operating range and the
oil pressure is still low, have the
vehicle serviced. Always follow the
maintenance schedule for changing
engine oil.
This light should come on briefly as
the engine is started. If it does not
come on, have the vehicle serviced by
your dealer.
If the light comes on and stays on, it
means that oil is not flowing through
the engine properly. The vehicle could
be low on oil and might have some
other system problem. See your dealer.
Low Fuel Warning Light
This light is near the fuel gauge and
comes on briefly when the ignition is
turned on as a check to show it is
working. For vehicles with a
reconfigurable cluster, this light is in
the display area and may not come on
when the ignition is turned on.
It also comes on when the fuel tank is
low on fuel. The light turns off when
fuel is added. If it does not, have the
vehicle serviced.
Security Light

Cadillac XTS Owner Manual (GMNA-Localizing-U.S./Canada-11354412) -
2018 - crc - 11/16/17
174 DRIVING AND OPERATING
{Warning
Wet brakes can cause crashes. They
might not work as well in a quick
stop and could cause pulling to one
side. You could lose control of the
vehicle.
After driving through a large puddle
of water or a car/vehicle wash,
lightly apply the brake pedal until
the brakes work normally.
Flowing or rushing water creates
strong forces. Driving through
flowing water could cause the
vehicle to be carried away. If this
happens, you and other vehicle
occupants could drown. Do not
ignore police warnings and be very
cautious about trying to drive
through flowing water.
Hydroplaning
Hydroplaning is dangerous. Water can
build up under the vehicle's tires so
they actually ride on the water. This
can happen if the road is wet enoughand you are going fast enough. When
the vehicle is hydroplaning, it has
little or no contact with the road.
There is no hard and fast rule about
hydroplaning. The best advice is to
slow down when the road is wet.
Other Rainy Weather Tips
Besides slowing down, other wet
weather driving tips include:
.
Allow extra following distance.
. Pass with caution.
. Keep windshield wiping equipment
in good shape.
. Keep the windshield washer fluid
reservoir filled.
. Have good tires with proper tread
depth. See Tires0267.
. Turn off cruise control.
Hill and Mountain Roads
Driving on steep hills or through
mountains is different than driving on
flat or rolling terrain. Tips include:
.Keep the vehicle serviced and in
good shape. .
Check all fluid levels and brakes,
tires, cooling system, and
transmission.
. Shift to a lower gear when going
down steep or long hills.
{Warning
Using the brakes to slow the vehicle
on a long downhill slope can cause
brake overheating, can reduce brake
performance, and could result in a
loss of braking. Shift the
transmission to a lower gear to let
the engine assist the brakes on a
steep downhill slope.
{Warning
Coasting downhill in N (Neutral) or
with the ignition off is dangerous.
This can cause overheating of the
brakes and loss of steering assist.
Always have the engine running
and the vehicle in gear.

Cadillac XTS Owner Manual (GMNA-Localizing-U.S./Canada-11354412) -
2018 - crc - 11/16/17
192 DRIVING AND OPERATING
The vehicle has an Electric Parking
Brake (EPB). The EPB can always be
activated, even if the ignition is off. To
prevent draining the battery, avoid
repeated cycles of the EPB system
when the engine is not running.
The system has a
Yor PARK
Electric Parking Brake light, and a
8
Service Parking Brake light.
See Electric Parking Brake Light 0130
and Service Electric Parking Brake Light
0 130.
Before leaving the vehicle, check for
the
Yor PARK light to ensure that
the parking brake is applied.
EPB Apply
To apply the EPB:
1. Be sure the vehicle is at a complete stop.
2. Press the EPB switch momentarily.
The
Yor PARK light will flash and
then stay on once the EPB is fully
applied. If the
Yor PARK light
flashes continuously, then the EPB is only partially applied or there is a
problem with the EPB. A DIC message
will display. Release the EPB and try
to apply it again. If the light does not
come on, or keeps flashing, have the
vehicle serviced. Do not drive the
vehicle if the
Yor PARK light is
flashing. See your dealer. See Electric
Parking Brake Light 0130.
If the
8light is on, press the EPB
switch and hold it. Continue to hold
the switch until the
Yor PARK light
remains on. If the
8light remains on,
see your dealer.
If the EPB is applied while the vehicle
is moving, the vehicle will decelerate
as long as the switch is pressed. If the
switch is pressed until the vehicle
comes to a stop, the EPB will remain
applied.
The vehicle may automatically apply
the EPB in some situations when the
vehicle is not moving. This is normal,
and is done to periodically check the
correct operation of the EPB system.
If the EPB fails to apply, block the rear
wheels to prevent vehicle movement.
EPB Release
To release the EPB:
1. Turn the ignition on or to ACC/ ACCESSORY.
2. Apply and hold the brake pedal.
3. Press the EPB switch momentarily.
The EPB is released when the
Yor
PARK light is off.
If the
8light is on, release the EPB by
pressing and holding the EPB switch.
Continue to hold the switch until
the
Yor PARK light is off. If either
light stays on after release is
attempted, see your dealer.
Caution
Driving with the parking brake on
can overheat the brake system and
cause premature wear or damage to
brake system parts. Make sure that
the parking brake is fully released
and the brake warning light is off
before driving.

Cadillac XTS Owner Manual (GMNA-Localizing-U.S./Canada-11354412) -
2018 - crc - 11/16/17
194 DRIVING AND OPERATING
pressure at any one of the vehicle's
brakes to help steer the vehicle in the
direction which you are steering.
If cruise control is being used and
traction control or StabiliTrak begins
to limit wheel spin, cruise control will
disengage. Cruise control may be
turned back on when road conditions
allow.
Both systems come on automatically
when the vehicle is started and begins
to move. The systems may be heard or
felt while they are operating or while
performing diagnostic checks. This is
normal and does not mean there is a
problem with the vehicle.
It is recommended to leave both
systems on for normal driving
conditions, but it may be necessary to
turn TCS off if the vehicle gets stuck
in sand, mud, ice, or snow. SeeIf the
Vehicle Is Stuck 0176 and “Turning
the Systems Off and On ”later in this
section.
The indicator light for both systems is
in the instrument cluster. This
light will:
. Flash when TCS is limiting
wheel spin.
. Flash when StabiliTrak is
activated.
. Turn on and stay on when either
system is not working.
If either system fails to turn on or to
activate, a message may display in the
Driver Information Center (DIC), and
dcomes on and stays on to indicate
that the system is inactive and is not
assisting the driver in maintaining
control. The vehicle is safe to drive,
but driving should be adjusted
accordingly.
If
dcomes on and stays on:
1. Stop the vehicle. 2. Turn the engine off and wait
15 seconds.
3. Start the engine.
Drive the vehicle. If
dcomes on and
stays on, the vehicle may need more
time to diagnose the problem. If the
condition persists, see your dealer.
Turning the Systems Off and On
The button for TCS and StabiliTrak is
on the center stack.

Cadillac XTS Owner Manual (GMNA-Localizing-U.S./Canada-11354412) -
2018 - crc - 11/16/17
DRIVING AND OPERATING 223
Caution (Continued)
.For vehicles which are not
FlexFuel, fuel labeled greater
than 15% ethanol by volume,
such as mid-level ethanol
blends (16 –50% ethanol),
E85, or FlexFuel.
. Fuel with any amount of
methanol, methylal, and
aniline. These fuels can
corrode metal fuel system
parts or damage plastic and
rubber parts.
. Fuel containing metals such
as methylcyclopentadienyl
manganese tricarbonyl
(MMT), which can damage
the emissions control system
and spark plugs.
. Fuel with a posted octane
rating of less than the
recommended fuel. Using this
fuel will lower fuel economy
and performance, and may
decrease the life of the
emissions catalyst.
California Fuel
Requirements
If the vehicle is certified to meet
California Emissions Standards, it is
designed to operate on fuels that meet
California specifications. See the
underhood emission control label.
If this fuel is not available in states
adopting California Emissions
Standards, the vehicle will operate
satisfactorily on fuels meeting federal
specifications, but emission control
system performance may be affected.
The malfunction indicator lamp could
turn on and the vehicle may not pass
a smog-check test. See Malfunction
Indicator Lamp (Check Engine Light)
0 128. If this occurs, return to your
authorized dealer for diagnosis. If it is
determined that the condition is
caused by the type of fuel used,
repairs may not be covered by the
vehicle warranty.
Fuels in Foreign Countries
The U.S., Canada, and Mexico post
fuel octane ratings in anti-knock index
(AKI). For fuel not to use in a foreign
country, see “Prohibited Fuels” inFuel
0 222.
Fuel Additives
To keep fuel systems clean, TOP TIER
detergent gasoline is recommended.
See Fuel 0222.
If TOP TIER detergent gasoline is not
available, one bottle of GM Fuel
System Treatment Cleaner added to
the fuel tank at every engine oil
change, can help. GM Fuel System
Treatment Cleaner is the only gasoline
additive recommended by General
Motors. It is available at your dealer.

Cadillac XTS Owner Manual (GMNA-Localizing-U.S./Canada-11354412) -
2018 - crc - 11/16/17
230 DRIVING AND OPERATING
.The rear bumper on the vehicle is
not intended for hitches. Do not
attach rental hitches or other
bumper-type hitches to it. Use
only a frame-mounted hitch that
does not attach to the bumper.
. Will any holes be made in the
body of the vehicle when the
trailer hitch is installed? If so, seal
the holes when the hitch is
removed. If the holes are not
sealed, dirt, water, and deadly
carbon monoxide (CO) from the
exhaust can get into the vehicle.
See Engine Exhaust 0187.
Safety Chains
Always attach chains between the
vehicle and the trailer. Cross the safety
chains under the tongue of the trailer
to help prevent the tongue from
contacting the road if it becomes
separated from the hitch. Leave
enough slack so the rig can turn.
Never allow safety chains to drag on
the ground.
Trailer Brakes
Does the trailer have its own brakes?
State and local regulations may
require the trailer to have its own
braking system if loaded above a
certain threshold. Trailer brake
requirements vary from state to state.
Be sure to read and follow the
instructions for the trailer brakes so
they are installed, adjusted, and
maintained properly.
Because the vehicle has antilock
brakes, do not tap into the vehicle's
brake system. If this is done, both
brake systems will not work well or
at all
Conversions and
Add-Ons
Add-On Electrical
Equipment
{Warning
The Data Link Connector (DLC) is
used for vehicle service and
Emission Inspection/Maintenance
testing. See Malfunction Indicator
Lamp (Check Engine Light) 0128.
A device connected to the DLC —
such as an aftermarket fleet or
driver-behavior tracking device —
may interfere with vehicle systems.
This could affect vehicle operation
and cause a crash. Such devices
may also access information stored
in the vehicle’s systems.

Cadillac XTS Owner Manual (GMNA-Localizing-U.S./Canada-11354412) -
2018 - crc - 11/16/17
232 VEHICLE CARE
Vehicle Care
General Information
General Information . . . . . . . . . . . . . 233
California Proposition65 Warning . . . . . . . . . . . . . . . . . . . . . 233
California Perchlorate Materials Requirements . . . . . . . . . . . . . . . . . . . 234
Accessories and Modifications . . . . . . . . . . . . . . . . . . . 234
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . . . . . . 234
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . . . . . . 236
Engine Cover . . . . . . . . . . . . . . . . . . . . . . 239
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . 240
Engine Oil Life System . . . . . . . . . . . 242
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243
Engine Air Cleaner/Filter . . . . . . . . . 243
Cooling System . . . . . . . . . . . . . . . . . . . 245
Engine Overheating . . . . . . . . . . . . . . 249
Overheated Engine Protection Operating Mode . . . . . . . . . . . . . . . . . 250
Power Steering Fluid (LFX with FWD) . . . . . . . . . . . . . . . . . . . . . . 250 Power Steering Fluid (LF3 and
LFX with AWD) . . . . . . . . . . . . . . . . . 250
Washer Fluid . . . . . . . . . . . . . . . . . . . . . 251
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . 253
Battery - North America . . . . . . . . . 254
All-Wheel Drive . . . . . . . . . . . . . . . . . . 254
Starter Switch Check . . . . . . . . . . . . . 254
Automatic Transmission Shift Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255
Park Brake and P (Park) Mechanism Check . . . . . . . . . . . . . . 255
Wiper Blade Replacement . . . . . . . 255
Windshield Replacement . . . . . . . . 256
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . 256
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . . . . . 258
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . . . . . 258
LED Lighting . . . . . . . . . . . . . . . . . . . . . 258
Back-Up Lamps . . . . . . . . . . . . . . . . . . . 258
License Plate Lamp . . . . . . . . . . . . . . 259
Electrical System
Electrical System Overload . . . . . . 259
Fuses and Circuit Breakers . . . . . . 260
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260 Instrument Panel Fuse Block . . . . 263
Rear Compartment Fuse
Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267
All-Season Tires . . . . . . . . . . . . . . . . . . 268
Winter Tires . . . . . . . . . . . . . . . . . . . . . . 268
Low-Profile Tires . . . . . . . . . . . . . . . . . 268
Summer Tires . . . . . . . . . . . . . . . . . . . . 269
Tire Sidewall Labeling . . . . . . . . . . . 269
Tire Designations . . . . . . . . . . . . . . . . . 271
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . . . . . . . 272
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . 274
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . . . . . . 276
Tire Pressure Monitor System . . . 276
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . . . . . . . . 277
Tire Inspection . . . . . . . . . . . . . . . . . . . 280
Tire Rotation . . . . . . . . . . . . . . . . . . . . . 280
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281
Buying New Tires . . . . . . . . . . . . . . . . 282
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . . . . . . . . 283
Uniform Tire Quality Grading . . . 284
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . . . . . . . . 285
Wheel Replacement . . . . . . . . . . . . . . 285

Cadillac XTS Owner Manual (GMNA-Localizing-U.S./Canada-11354412) -
2018 - crc - 11/16/17
VEHICLE CARE 249
The CAC bottle pressure cap can be
removed when the Charged Air
Coolant cooling system, including the
CAC bottle pressure cap, is no
longer hot.
1. Turn the pressure cap slowlycounterclockwise and remove it.
2. Fill the CAC bottle with the proper mixture to the cold fill
mark pointed to on the front of
the CAC bottle.
3. Replace the pressure cap tightly.
Caution
If the pressure cap is not tightly
installed, coolant loss and engine
damage may occur. Be sure the cap
is properly and tightly secured.
Engine Overheating
The vehicle has an engine coolant
temperature gauge and an engine
temperature light to warn of engine
overheating.
There are also engine hot messages
that may display in the Driver
Information Center (DIC).
If the decision is made not to lift the
hood when one of these warnings
appears, but get service help right
away. See Roadside Service 0338.
If the decision is made to lift the
hood, make sure the vehicle is parked
on a level surface.
Then check to see if the engine
cooling fans are running. If the engine
is overheating, the fans should be
running. If they are not, do not
continue to run the engine. Have the
vehicle serviced.Caution
Do not run the engine if there is a
leak in the engine cooling system.
This can cause a loss of all coolant
and can damage the system and
vehicle. Have any leaks fixed
right away.
If Steam Is Coming from the
Engine Compartment
{Warning
Steam and scalding liquids from a
hot cooling system are under
pressure. Turning the pressure cap,
even a little, can cause them to
come out at high speed and you
could be burned. Never turn the cap
when the cooling system, including
the pressure cap, is hot. Wait for
the cooling system and pressure
cap to cool.

Cadillac XTS Owner Manual (GMNA-Localizing-U.S./Canada-11354412) -
2018 - crc - 11/16/17
250 VEHICLE CARE
If No Steam Is Coming from the
Engine Compartment
If an engine overheat warning is
displayed but no steam can be seen or
heard, the problem may not be too
serious. Sometimes the engine can get
a little too hot when the vehicle:
.Climbs a long hill on a hot day.
. Stops after high-speed driving.
. Idles for long periods in traffic.
. Tows a trailer.
If the overheat warning is displayed
with no sign of steam: 1. Turn the air conditioning off.
2. Turn the heater on to the highest temperature and to the highest
fan speed. Open the windows as
necessary.
3. When it is safe to do so, pull off the road, shift to P (Park) or
N (Neutral), and let the
engine idle.
If the temperature overheat gauge is
no longer in the overheat zone or an
overheat warning no longer displays,
the vehicle can be driven. Continue to drive the vehicle slow for about
10 minutes. Keep a safe vehicle
distance from the car in front of you.
If the warning does not come back on,
continue to drive normally and have
the cooling system checked for proper
fill and function.
If the warning continues, pull over,
stop, and park the vehicle right away.
If there is no sign of steam, idle the
engine for three minutes while parked.
If the warning is still displayed, turn
off the engine until it cools down.
Also, see
“Overheated Engine
Protection Operating Mode ”next in
this section.
Overheated Engine
Protection Operating Mode
This emergency operating mode
allows the vehicle to be driven to a
safe place in an emergency situation.
If an overheated engine condition
exists, an overheat protection mode,
which alternates firing groups of
cylinders, helps prevent engine damage. In this mode, there is
significant loss in power and engine
performance.
The engine coolant temperature
warning light comes on in the
instrument cluster, to indicate the
vehicle has entered overheated engine
protection operating mode. The
temperature gauge also indicates an
overheat condition exists. Driving
extended distances and/or towing a
trailer in the overheat protection
mode should be avoided.
Power Steering Fluid (LFX
with FWD)
The vehicle has electric power steering
and does not use power steering fluid.
Power Steering Fluid
(LF3 and LFX with AWD)

Cadillac XTS Owner Manual (GMNA-Localizing-U.S./Canada-11354412) -
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VEHICLE CARE 253
many other ways if the wrong
replacement brake parts are installed
or if parts are improperly installed.
Brake Fluid
The brake master cylinder reservoir is
filled with GM approved DOT 3 brake
fluid as indicated on the reservoir cap.
SeeEngine Compartment Overview
0 236 for the location of the reservoir.
Checking Brake Fluid
With the vehicle in P (Park) on a level
surface, the brake fluid level should be
between the minimum and maximum
marks on the brake fluid reservoir.
There are only two reasons why the
brake fluid level in the reservoir may
go down:
. Normal brake lining wear. When
new linings are installed, the fluid
level goes back up. .
A fluid leak in the brake hydraulic
system. Have the brake hydraulic
system fixed. With a leak, the
brakes will not work well.
Always clean the brake fluid reservoir
cap and the area around the cap
before removing it.
Do not top off the brake fluid. Adding
fluid does not correct a leak. If fluid is
added when the linings are worn,
there will be too much fluid when
new brake linings are installed. Add or
remove fluid, as necessary, only when
work is done on the brake hydraulic
system.
{Warning
If too much brake fluid is added, it
can spill on the engine and burn,
if the engine is hot enough. You or
others could be burned, and the
vehicle could be damaged. Add
brake fluid only when work is done
on the brake hydraulic system. When the brake fluid falls to a low
level, the brake warning light comes
on. See
Brake System Warning Light
0 129.
Brake fluid absorbs water over time
which degrades the effectiveness of
the brake fluid. Replace brake fluid at
the specified intervals to prevent
increased stopping distance. See
Maintenance Schedule 0317.
What to Add
Use only GM approved DOT 3 brake
fluid from a clean, sealed container.
See Recommended Fluids and
Lubricants 0326.
{Warning
The wrong or contaminated brake
fluid could result in damage to the
brake system. This could result in
the loss of braking leading to a
possible injury. Always use the
proper GM approved brake fluid.