engine overheat CADILLAC ATS 2018 User Guide

Cadillac XTS Owner Manual (GMNA-Localizing-U.S./Canada-12032610) -
2019 - crc - 8/22/18
DRIVING AND OPERATING 231
and not as responsive as the vehicle
itself. Get acquainted with the
handling and braking of the rig before
setting out for the open road.
Before starting, check all trailer hitch
parts and attachments, safety chains,
electrical connectors, lamps, tires, and
mirrors. If the trailer has electric
brakes, start the combination moving
and then apply the trailer brake
controller by hand to be sure the
brakes work.
During the trip, check occasionally to
be sure that the load is secure and the
lamps and any trailer brakes
still work.
Following Distance
Stay at least twice as far behind the
vehicle ahead as you would when
driving the vehicle without a trailer.
This can help to avoid heavy braking
and sudden turns.
Passing
More passing distance is needed when
towing a trailer. The combination will
not accelerate as quickly and is longer,so it is necessary to go much farther
beyond the passed vehicle before
returning to the lane.
Backing Up
Hold the bottom of the steering wheel
with one hand. To move the trailer to
the left, move that hand to the left. To
move the trailer to the right, move
your hand to the right. Always back
up slowly and, if possible, have
someone guide you.
Making Turns
Caution
Making very sharp turns while
trailering could cause the trailer to
come in contact with the vehicle.
The vehicle could be damaged.
Avoid making very sharp turns
while trailering.
When turning with a trailer, make
wider turns than normal. Do this so
the trailer will not strike soft shoulders, curbs, road signs, trees,
or other objects. Avoid jerky or sudden
maneuvers. Signal well in advance.
If the trailer turn signal bulbs burn
out, the arrows on the instrument
cluster will still flash for turns. It is
important to check occasionally to be
sure the trailer bulbs are still working.
Driving on Grades
Reduce speed and shift to a lower gear
before
starting down a long or steep
downgrade. If the transmission is not
shifted down, the brakes might get hot
and no longer work well.
Vehicles can tow in D (Drive). Shift
the transmission to a lower gear if the
transmission shifts too often under
heavy loads and/or hilly conditions.
When towing at high altitude on steep
uphill grades, consider the following:
Engine coolant will boil at a lower
temperature than at normal altitudes.
If the engine is turned off immediately
after towing at high altitude on steep
uphill grades, the vehicle may show
signs similar to engine overheating. To
avoid this, let the engine run while
parked, preferably on level ground,

Cadillac XTS Owner Manual (GMNA-Localizing-U.S./Canada-12032610) -
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232 DRIVING AND OPERATING
with the automatic transmission in
P (Park) for a few minutes before
turning the engine off. If the overheat
warning comes on, seeEngine
Overheating 0253.
Parking on Hills
{Warning
Parking the vehicle on a hill with
the trailer attached can be
dangerous. If something goes
wrong, the rig could start to move.
People can be injured, and both the
vehicle and the trailer can be
damaged. When possible, always
park the rig on a flat surface.
If parking the rig on a hill: 1. Press the brake pedal, but do not shift into P (Park) yet. Turn the
wheels into the curb if facing
downhill or into traffic if facing
uphill.
2. Have someone place chocks under the trailer wheels. 3. When the wheel chocks are in
place, release the regular brakes
until the chocks absorb the load.
4. Reapply the brake pedal. Then apply the parking brake and shift
into P (Park).
5. Release the brake pedal.
Leaving After Parking on a Hill
1. Apply and hold the brake pedal.
2. Start the engine.
3. Shift into a gear.
4. Release the parking brake.
5. Let up on the brake pedal.
6. Drive slowly until the trailer is clear of the chocks.
7. Stop and have someone pick up and store the chocks.
Maintenance when Trailer
Towing
The vehicle needs service more often
when pulling a trailer. See
Maintenance Schedule 0322. Things
that are especially important in trailer
operation are automatic transmission fluid, engine oil, axle lubricant, belts,
cooling system, and brake system. It is
a good idea to inspect these before
and during the trip.
Check periodically to see that all hitch
nuts and bolts are tight.
Trailer Towing
{Warning
The driver can lose control when
pulling a trailer if the correct
equipment is not used or the
vehicle is not driven properly. For
example, if the trailer is too heavy
or the trailer brakes are inadequate
for the load, the vehicle may not
stop as expected. The driver and
passengers could be seriously
injured. The vehicle may also be
damaged; the resulting repairs
would not be covered by the vehicle
warranty. Pull a trailer only if all the
steps in this section have been
followed. Ask your dealer for advice
and information about towing a
trailer with the vehicle.

Cadillac XTS Owner Manual (GMNA-Localizing-U.S./Canada-12032610) -
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236 VEHICLE CARE
Vehicle Care
General Information
General Information . . . . . . . . . . . . . 237
California Proposition65 Warning . . . . . . . . . . . . . . . . . . . . . 237
California Perchlorate Materials Requirements . . . . . . . . . . . . . . . . . . . 238
Accessories and Modifications . . . . . . . . . . . . . . . . . . . 238
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . . . . . . 238
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . . . . . . 240
Engine Cover . . . . . . . . . . . . . . . . . . . . . . 243
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . 244
Engine Oil Life System . . . . . . . . . . . 246
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
Engine Air Cleaner/Filter . . . . . . . . . 248
Cooling System . . . . . . . . . . . . . . . . . . . 250
Engine Overheating . . . . . . . . . . . . . . 253
Overheated Engine Protection Operating Mode . . . . . . . . . . . . . . . . . 254
Power Steering Fluid (LF3 and LFX with AWD) . . . . . . . . . . . . . . . . . 255 Power Steering Fluid (LFX
with FWD) . . . . . . . . . . . . . . . . . . . . . . 255
Washer Fluid . . . . . . . . . . . . . . . . . . . . . 256
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . 257
Battery - North America . . . . . . . . . 258
All-Wheel Drive . . . . . . . . . . . . . . . . . . 259
Starter Switch Check . . . . . . . . . . . . . 259
Automatic Transmission Shift Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259
Park Brake and P (Park) Mechanism Check . . . . . . . . . . . . . . 260
Wiper Blade Replacement . . . . . . . 260
Windshield Replacement . . . . . . . . 261
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . 261
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . . . . . 262
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . . . . . 263
LED Lighting . . . . . . . . . . . . . . . . . . . . . 263
Back-Up Lamps . . . . . . . . . . . . . . . . . . . 263
License Plate Lamp . . . . . . . . . . . . . . 264
Electrical System
Electrical System Overload . . . . . . 264
Fuses and Circuit Breakers . . . . . . 265
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265 Instrument Panel Fuse Block . . . . 268
Rear Compartment Fuse
Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272
All-Season Tires . . . . . . . . . . . . . . . . . . 273
Winter Tires . . . . . . . . . . . . . . . . . . . . . . 273
Low-Profile Tires . . . . . . . . . . . . . . . . . 273
Summer Tires . . . . . . . . . . . . . . . . . . . . 273
Tire Sidewall Labeling . . . . . . . . . . . 274
Tire Designations . . . . . . . . . . . . . . . . . 276
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . . . . . . . 277
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . 279
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . . . . . . 281
Tire Pressure Monitor System . . . 281
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . . . . . . . . 282
Tire Inspection . . . . . . . . . . . . . . . . . . . 285
Tire Rotation . . . . . . . . . . . . . . . . . . . . . 285
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286
Buying New Tires . . . . . . . . . . . . . . . . 287
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . . . . . . . . 288
Uniform Tire Quality Grading . . . 289
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . . . . . . . . 290
Wheel Replacement . . . . . . . . . . . . . . 290

Cadillac XTS Owner Manual (GMNA-Localizing-U.S./Canada-12032610) -
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250 VEHICLE CARE
Cooling System
The cooling system allows the engine
to maintain the correct working
temperature.
3.6L V6 Engine
1. Electric Engine Cooling Fans(Out of View)
2. Coolant Surge Tank and Pressure Cap
3.6L V6 Twin Turbo Engine
1. Electric Engine Cooling Fans(Out of View)
2. Charged Air Coolant (CAC) Bottle and Pressure Cap
3. Coolant Surge Tank and Pressure Cap
{Warning
An underhood electric fan can start
up even when the engine is not
running and can cause injury. Keep
hands, clothing, and tools away
from any underhood electric fan.
{Warning
Do not touch heater or radiator
hoses, or other engine parts. They
can be very hot and can burn you.
Do not run the engine if there is a
leak; all coolant could leak out.
That could cause an engine fire and
can burn you. Fix any leak before
driving the vehicle.
Engine Coolant
The engine and Charged Air Coolant
(CAC) cooling systems in the vehicle
are filled with DEX-COOL engine
coolant mixture.
See Recommended Fluids and
Lubricants 0332 and Maintenance
Schedule 0322.
The following explains the cooling
systems and how to check and add
coolant when it is low. If there is a
problem with engine overheating, see
Engine Overheating 0253.

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What to Use
{Warning
Plain water, or other liquids such as
alcohol, can boil before the proper
coolant mixture will. With plain
water or the wrong mixture, the
engine could get too hot but there
would not be an overheat warning.
The engine could catch fire and you
or others could be burned.
Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
coolant. This mixture:
. Gives freezing protection down to
−37 °C (−34 °F), outside
temperature.
. Gives boiling protection up to
129 °C (265 °F), engine
temperature.
. Protects against rust and
corrosion.
. Will not damage aluminum parts.
. Helps keep the proper engine
temperature.
Caution
Do not use anything other than a
mix of DEX-COOL coolant that
meets GM Standard GMW3420 and
clean, drinkable water. Anything
else can cause damage to the
engine cooling system and the
vehicle, which would not be covered
by the vehicle warranty.
Never dispose of engine coolant by
putting it in the trash, pouring it on
the ground, or pouring into sewers,
streams, or bodies of water. Have the
coolant changed by an authorized
service center, familiar with legal
requirements regarding used coolant
disposal. This will help protect the
environment and your health.
Checking Coolant
The vehicle must be on a level surface
when checking the coolant level. The engine coolant surge tank and
CAC bottle are in the engine
compartment on the driver side of the
vehicle. See
Engine Compartment
Overview 0240.
Check to see if coolant is visible in the
surge tank and CAC bottle. If the
coolant inside the surge tank is
boiling, do not do anything else until
it cools down. If coolant is visible but
the coolant level is not at or above the
mark pointed to on the surge tank or
at the CAC bottle cold fill mark, add a
50/50 mixture of clean, drinkable
water and DEX-COOL coolant.
Be sure the cooling system is cool
before this is done.
If no coolant is visible in the coolant
surge tank or CAC bottle, add coolant
as follows:

Cadillac XTS Owner Manual (GMNA-Localizing-U.S./Canada-12032610) -
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252 VEHICLE CARE
How to Add Coolant to the
Surge Tank
{Warning
Plain water, or other liquids such as
alcohol, can boil before the proper
coolant mixture will. With plain
water or the wrong mixture, the
engine could get too hot but there
would not be an overheat warning.
The engine could catch fire and you
or others could be burned.
{Warning
Spilling coolant on hot engine parts
can burn you. Coolant contains
ethylene glycol and it will burn if
the engine parts are hot enough.
Caution
Failure to follow the specific
coolant fill procedure could cause
the engine to overheat and could
cause system damage. If coolant is
not visible in the surge tank,
contact your dealer.
The coolant surge tank pressure cap
can be removed when the cooling
system, including the surge tank
pressure cap and upper radiator hose,
is no longer hot.
1. Turn the pressure cap slowly counterclockwise. If a hiss is
heard, wait for that to stop.
A hiss means there is still some
pressure left.
2. Keep turning the pressure cap slowly and remove it. 3. Fill the coolant surge tank with
the proper mixture to the mark
pointed to on the front of the
coolant surge tank.
4. With the coolant surge tank pressure cap off, start the engine,
and let it run until you can feel
the upper radiator hose getting
hot. Watch out for the engine
cooling fans. By this time, the
coolant level inside the coolant
surge tank may be lower. If the
level is lower, add more of the
proper mixture to the coolant
surge tank until the level reaches
the mark pointed to on the front
of the coolant surge tank.
5. Replace the pressure cap tightly.
6. Verify coolant level after the engine is shut off and the
coolant is cold. If necessary,
repeat coolant fill procedure
Steps 1–5.

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VEHICLE CARE 253
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.
How to Add Coolant to the CAC
Bottle
{Warning
Spilling coolant on hot engine parts
can burn you. Coolant contains
ethylene glycol and it will burn if
the engine parts are hot enough.
Caution
Failure to follow the specific
coolant fill procedure could cause
the engine to overheat and could
cause system damage. If coolant is
not visible in the surge tank,
contact your dealer.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 slowly
counterclockwise 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 0343.
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.

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254 VEHICLE CARE
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.
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

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VEHICLE CARE 255
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
(LF3 and LFX with AWD)
The power steering fluid reservoir is
under the engine cover on the
passenger side toward the rear of the
engine compartment. SeeEngine
Compartment Overview 0240.
When to Check Power Steering
Fluid
It is not necessary to regularly check
power steering fluid unless you
suspect there is a leak in the system
or an unusual noise is heard. A fluid
loss in this system could indicate a
problem. Have the system inspected
and repaired.
How to Check Power Steering
Fluid
Check the level when the engine
is cool.
To check the power steering fluid:
1. Remove the engine cover. Refer toEngine Cover 0243.
2. Wipe the cap and the top of the reservoir clean.
3. Turn the cap counterclockwise and pull it straight up.
4. Wipe the dipstick with a clean rag.
5. Replace the cap and completely tighten it. 6. Remove the cap again and look
at the fluid level on the dipstick.
The fluid level should be
between MIN and MAX on the
dipstick.
What to Use
To determine what kind of fluid to
use, see Recommended Fluids and
Lubricants 0332. Always use the
proper fluid.
Power Steering Fluid (LFX
with FWD)
The vehicle has electric power steering
and does not use power steering fluid.

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Headlamp Wiring
An electrical overload may cause the
lamps to go on and off, or in some
cases to remain off. Have the
headlamp wiring checked right away if
the lamps go on and off or remain off.
Windshield Wipers
If the wiper motor overheats due to
heavy snow or ice, the windshield
wipers will stop until the motor cools
and will then restart.
Although the circuit is protected from
electrical overload, overload due to
heavy snow or ice may cause wiper
linkage damage. Always clear ice and
heavy snow from the windshield
before using the windshield wipers.
If the overload is caused by an
electrical problem and not snow or
ice, be sure to get it fixed.
Fuses and Circuit Breakers
The wiring circuits in the vehicle are
protected from short circuits by a
combination of fuses and circuitbreakers. This greatly reduces the
chance of damage caused by electrical
problems.
{Danger
Fuses and circuit breakers are
marked with their ampere rating.
Do not exceed the
specified amperage rating when
replacing fuses and circuit breakers.
Use of an oversized fuse or circuit
breaker can result in a vehicle fire.
You and others could be seriously
injured or killed.
To check a fuse, look at the
silver-colored band inside the fuse.
If the band is broken or melted,
replace the fuse. Be sure to replace a
bad fuse with a new one of the
identical size and rating.
Fuses of the same amperage can be
temporarily borrowed from another
fuse location, if a fuse goes out.
Replace the fuse as soon as possible.
Engine Compartment Fuse
Block
To remove the fuse block cover,
squeeze the three retaining clips on
the cover and lift it straight up.
Caution
Spilling liquid on any electrical
component on the vehicle may
damage it. Always keep the covers
on any electrical component.