2018 CADILLAC ATS check engine

Cadillac XTS Owner Manual (GMNA-Localizing-U.S./Canada-12032610) -
2019 - crc - 8/22/18
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) -
2019 - crc - 8/22/18
244 VEHICLE CARE
3.6L V6 Engine Twin Turbo Engine
1. Engine Oil Fill Cap
2. Engine Cover
3. Engine Cover Bolt
To remove:1. Remove the oil fill cap (1).
2. Remove the engine cover bolt (3).
3. Raise the engine cover (2) to release it from the retainers.
4. Lift and remove the engine cover.
5. Reverse Steps 1–4 to reinstall the engine cover.
Engine Oil
To ensure proper engine performance
and long life, careful attention must
be paid to engine oil. Following these
simple, but important steps will help
protect your investment:
.Use engine oil approved to the
proper specification and of the
proper viscosity grade. See
“Selecting the Right Engine Oil” in
this section.
. Check the engine oil level regularly
and maintain the proper oil level.
See “Checking Engine Oil” and
“When to Add Engine Oil” in this
section.
. Change the engine oil at the
appropriate time. See Engine Oil
Life System 0246.
. Always dispose of engine oil
properly. See “What to Do with
Used Oil” in this section.
Checking Engine Oil
Check the engine oil level regularly,
every 650 km (400 mi), especially prior
to a long trip. The engine oil dipstick handle is a loop. See
Engine
Compartment Overview 0240 for the
location.
{Warning
The engine oil dipstick handle may
be hot; it could burn you. Use a
towel or glove to touch the dipstick
handle.
If a low oil Driver Information Center
(DIC) message displays, check the oil
level.
Follow these guidelines:
. To get an accurate reading, park
the vehicle on level ground. Check
the engine oil level after the
engine has been off for at least
two hours. Checking the engine oil
level on steep grades or too soon
after engine shutoff can result in
incorrect readings. Accuracy
improves when checking a cold
engine prior to starting. Remove
the dipstick and check the level.

Cadillac XTS Owner Manual (GMNA-Localizing-U.S./Canada-12032610) -
2019 - crc - 8/22/18
VEHICLE CARE 245
.If unable to wait two hours, the
engine must be off for at least
15 minutes if the engine is warm,
or at least 30 minutes if the
engine is not warm. Pull out the
dipstick, wipe it with a clean paper
towel or cloth, then push it back
in all the way. Remove it again,
keeping the tip down, and check
the level.
When to Add Engine Oil
3.6L V6 Engine
3.6L V6 Twin Turbo Engine
If the oil is below the cross-hatched
area at the tip of the dipstick and the
engine has been off for at least
15 minutes, add 1 L (1 qt) of the
recommended oil and then recheck
the level. See “Selecting the Right
Engine Oil” later in this section for an
explanation of what kind of oil to use.
For engine oil crankcase capacity, see
Capacities and Specifications 0337.
Caution
Do not add too much oil. Oil levels
above or below the acceptable
operating range shown on the
dipstick are harmful to the engine.
If the oil level is above the
operating range (i.e., the engine has
so much oil that the oil level gets
(Continued)
Caution (Continued)
above the cross-hatched area that
shows the proper operating range),
the engine could be damaged. Drain
the excess oil or limit driving of the
vehicle, and seek a service
professional to remove the
excess oil.
See Engine Compartment Overview
0 240 for the location of the engine oil
fill cap.
Add enough oil to put the level
somewhere in the proper operating
range. Push the dipstick all the way
back in when through.
Selecting the Right Engine Oil
Selecting the right engine oil depends
on both the proper oil specification
and viscosity grade. See Recommended
Fluids and Lubricants 0332.
Specification
Use full synthetic engine oils that
meet the dexos1 specification. Engine
oils that have been approved by GM

Cadillac XTS Owner Manual (GMNA-Localizing-U.S./Canada-12032610) -
2019 - crc - 8/22/18
VEHICLE CARE 247
When the system has calculated that
oil life has been diminished, it
indicates that an oil change is
necessary. A CHANGE ENGINE OIL
SOON message comes on. Change the
oil as soon as possible within the next
1 000 km (600 mi). It is possible that,
if driving under the best conditions,
the oil life system might indicate that
an oil change is not necessary for up
to a year. The engine oil and filter
must be changed at least once a year
and at this time the system must be
reset. Your dealer has trained service
people who will perform this work and
reset the system. It is also important
to check the oil regularly over the
course of an oil drain interval and
keep it at the proper level.
If the system is ever reset accidentally,
the oil must be changed at 5 000 km
(3,000 mi) since the last oil change.
Remember to reset the oil life system
whenever the oil is changed.How to Reset the Engine Oil Life
System
Reset the system whenever the engine
oil is changed so that the system can
calculate the next engine oil change.
To reset the system:1. Using the DIC buttons, display REMAINING OIL LIFE on the
DIC. See Driver Information Center
(DIC) 0139.
2. Press and hold SEL to clear the CHANGE ENGINE OIL SOON
message and reset the oil life
at 100%.
Be careful not to reset the oil life
display accidentally at any time
other than after the oil is
changed. It cannot be reset
accurately until the next oil
change.
The oil life system can also be reset as
follows:
1. Display REMAINING OIL LIFE on the DIC. See Driver Information
Center (DIC) 0139. 2. Fully press and release the
accelerator pedal three times
within five seconds.
If the CHANGE ENGINE OIL
SOON message is not on, the
system is reset.
The system is reset when the
CHANGE ENGINE OIL SOON message
is off.
If the CHANGE ENGINE OIL SOON
message comes back on when the
vehicle is started, the engine oil life
system has not been reset. Repeat the
procedure.
Automatic Transmission
Fluid
A transmission fluid leak is the only
reason for fluid loss. If a leak occurs,
take the vehicle to your dealer and
have it repaired as soon as possible.

Cadillac XTS Owner Manual (GMNA-Localizing-U.S./Canada-12032610) -
2019 - crc - 8/22/18
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.

Cadillac XTS Owner Manual (GMNA-Localizing-U.S./Canada-12032610) -
2019 - crc - 8/22/18
VEHICLE CARE 251
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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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.

Cadillac XTS Owner Manual (GMNA-Localizing-U.S./Canada-12032610) -
2019 - crc - 8/22/18
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