2018 CADILLAC XTS check engine light

Cadillac XTS Owner Manual (GMNA-Localizing-U.S./Canada-11354412) -
2018 - crc - 11/16/17
INSTRUMENTS AND CONTROLS 129
If the light continues to flash, find a
safe place to park. Turn the vehicle off
and wait at least 10 seconds before
restarting the engine. If the light is
still flashing, follow the previous
guidelines and see your dealer for
service as soon as possible.
If the light is on steady :A
malfunction has been detected.
Diagnosis and service may be
required.
Check the following:
. If fuel has been added to the
vehicle using the capless fuel
funnel adapter, make sure that it
has been removed. See “Filling the
Tank with a Portable Gas Can ”
under Filling the Tank 0224. The
diagnostic system can detect if the
adapter has been left installed in
the vehicle, allowing fuel to
evaporate into the atmosphere.
A few driving trips with the
adapter removed may turn off the
light.
. Poor fuel quality can cause
inefficient engine operation and
poor driveability, which may go away once the engine is warmed
up. If this occurs, change the fuel
brand. It may require at least one
full tank of the proper fuel to turn
the light off. See
Fuel0222.
If the light remains on, see your
dealer.
Emissions Inspection and
Maintenance Programs
If the vehicle requires an Emissions
Inspection/Maintenance test, the test
equipment will likely connect to the
vehicle's Data Link Connector (DLC).
The DLC is under the instrument
panel to the left of the steering wheel.
Connecting devices that are not used
to perform an Emissions Inspection/
Maintenance test or to service the
vehicle may affect vehicle operation.
See Add-On Electrical Equipment 0230.
See your dealer if assistance is needed. The vehicle may not pass
inspection if:
.
The light is on when the engine is
running.
. The light does not come on when
the ignition is in Service Mode.
. Critical emission control systems
have not been completely
diagnosed. If this happens, the
vehicle would not be ready for
inspection and might require
several days of routine driving
before the system is ready for
inspection. This can happen if the
12-volt battery has recently been
replaced or run down, or if the
vehicle has been recently serviced.
See your dealer if the vehicle will not
pass or cannot be made ready for
the test.Brake System Warning
Light
The vehicle brake system consists of
two hydraulic circuits. If one circuit is
not working, the remaining circuit can

Cadillac XTS Owner Manual (GMNA-Localizing-U.S./Canada-11354412) -
2018 - crc - 11/16/17
INSTRUMENTS AND CONTROLS 133
Traction Control System
(TCS)/StabiliTrak Light
This light comes on briefly when the
engine is started.
If the light does not come on, have
the vehicle serviced by your dealer.
If the system is working normally, the
indicator light turns off.
If the light is on and not flashing, the
TCS and potentially the StabiliTrak
system have been disabled. A Driver
Information Center (DIC) message
may display. Check the DIC messages
to determine which feature(s) is no
longer functioning and whether the
vehicle requires service.
If the light is on and flashing, the TCS
and/or the StabiliTrak system is
actively working.See
Traction Control/Electronic Stability
Control 0193.
Engine Coolant
Temperature Warning Light
On some vehicles this light comes on
briefly while starting the vehicle. If it
does not, have the vehicle serviced by
the dealer. If the system is working
normally the indicator light goes off.
For vehicles with the reconfigurable
cluster, this light may not come on
when starting the vehicle.
Caution
The engine coolant temperature
warning light indicates that the
vehicle has overheated. Driving with
this light on can damage the engine
(Continued)
Caution (Continued)
and it may not be covered by the
vehicle warranty. SeeEngine
Overheating 0249.
The engine coolant temperature
warning light comes on when the
engine has overheated.
If this happens pull over and turn off
the engine as soon as possible. See
Engine Overheating 0249.
Tire Pressure Light
For vehicles with the Tire Pressure
Monitor System (TPMS), this light
comes on briefly when the engine is
started. It provides information about
tire pressures and the TPMS.

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.