check engine CADILLAC CTS 2018 Owner's Guide

Cadillac CTS/CTS-V Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
11349156) - 2018 - CRC - 9/29/17
DRIVING AND OPERATING 251
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
Towing Equipment (V6
Twin Turbo)
The vehicle is neither designed nor
intended to tow a trailer.
Conversions and
Add-Ons
Add-On Electrical
Equipment
{Warning
The Data Link Connector (DLC) is
used for vehicle service and
Emission Inspection/Maintenance
testing. SeeMalfunction 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.
Caution
Some electrical equipment can
damage the vehicle or cause
components to not work and would
not be covered by the vehicle
warranty. Always check with your
dealer before adding electrical
equipment.
Add-on equipment can drain the
vehicle's 12-volt battery, even if the
vehicle is not operating.
The vehicle has an airbag system.
Before attempting to add anything
electrical to the vehicle, see Servicing
the Airbag-Equipped Vehicle 086 and
Adding Equipment to the
Airbag-Equipped Vehicle 087.

Cadillac CTS/CTS-V Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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252 VEHICLE CARE
Vehicle Care
General Information
General Information . . . . . . . . . . . . . 253
California Proposition65 Warning . . . . . . . . . . . . . . . . . . . . . 253
California Perchlorate Materials Requirements . . . . . . . . . . . . . . . . . . . 254
Accessories and Modifications . . . . . . . . . . . . . . . . . . . 254
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . . . . . . 254
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . . . . . . 256
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . 263
Engine Oil Life System . . . . . . . . . . . 265
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266
Engine Air Cleaner/Filter . . . . . . . . . 267
Cooling System . . . . . . . . . . . . . . . . . . . 269
Engine Overheating . . . . . . . . . . . . . . 274
Washer Fluid . . . . . . . . . . . . . . . . . . . . . 275
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . 276
Battery - North America . . . . . . . . . 277
All-Wheel Drive . . . . . . . . . . . . . . . . . . 279 Starter Switch Check . . . . . . . . . . . . . 279
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280
Park Brake and P (Park)
Mechanism Check . . . . . . . . . . . . . . 280
Wiper Blade Replacement . . . . . . . 280
Windshield Replacement . . . . . . . . 281
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . 281
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . . . . . 282
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . . . . . 283
Halogen Bulbs . . . . . . . . . . . . . . . . . . . . 283
High Intensity Discharge (HID) Lighting . . . . . . . . . . . . . . . . . . . . . . . . . 283
LED Lighting . . . . . . . . . . . . . . . . . . . . . 283
Back-Up Lamps . . . . . . . . . . . . . . . . . . . 283
License Plate Lamp . . . . . . . . . . . . . . 284
Electrical System
Electrical System Overload . . . . . . 285
Fuses and Circuit Breakers . . . . . . 285
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286
Instrument Panel Fuse Block . . . . 289
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294
All-Season Tires . . . . . . . . . . . . . . . . . . 295
Winter Tires . . . . . . . . . . . . . . . . . . . . . . 295
Run-Flat Tires . . . . . . . . . . . . . . . . . . . . 295
Low-Profile Tires . . . . . . . . . . . . . . . . . 296
Summer Tires . . . . . . . . . . . . . . . . . . . . 296
Tire Sidewall Labeling . . . . . . . . . . . 297
Tire Designations . . . . . . . . . . . . . . . . . 298
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . . . . . . . 299
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . 301
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . . . . . . 302
Tire Pressure Monitor System . . . 303
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . . . . . . . . 304
Tire Inspection . . . . . . . . . . . . . . . . . . . 307
Tire Rotation . . . . . . . . . . . . . . . . . . . . . 307
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308
Buying New Tires . . . . . . . . . . . . . . . . 309
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . . . . . . . . 311
Uniform Tire Quality Grading . . . 311
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . . . . . . . . 312
Wheel Replacement . . . . . . . . . . . . . . 313
Tire Chains . . . . . . . . . . . . . . . . . . . . . . . 313
If a Tire Goes Flat . . . . . . . . . . . . . . . . 314

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1. Windshield Washer FluidReservoir. See Washer Fluid
0 275.
2. Remote Positive (+) Battery Terminal. See Jump Starting -
North America 0323.
3. Engine Compartment Fuse Block
0286.
4. Engine Coolant Surge Tank and Pressure Cap. See Cooling System
0 269.
5. Remote Negative (-) Battery Terminal. See Jump Starting -
North America 0323.
6. Engine Oil Dipstick. See Engine
Oil 0263.
7. Engine Cooling Fan (Out of View). See Cooling System 0269.
8. Engine Oil Fill Cap (Out of View). See Engine Oil 0263.
9. Engine Air Cleaner/Filter 0267.
10. Brake Fluid Reservoir. See Brake
Fluid 0276.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 0265.
. 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 0256 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 CTS/CTS-V Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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264 VEHICLE CARE
.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
2.0L L4 Turbo (LTG)
3.6L V6 Twin Turbo (LF3)
3.6L V6 (LGX) Shown, 6.2L V8 (LT4)
Similar
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 0353.
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 you find that you have an oil
level above the operating range, i.e.,
(Continued)
Caution (Continued)
the engine has so much oil that the
oil level gets above the
cross-hatched area that shows the
proper operating range, the engine
could be damaged. You should
drain out the excess oil or limit
driving of the vehicle and seek a
service professional to remove the
excess amount of oil.
See Engine Compartment Overview
0 256 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 0348.

Cadillac CTS/CTS-V Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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266 VEHICLE CARE
vary considerably. For the oil life
system to work properly, the system
must be reset every time the oil is
changed.
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) 0137.
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) 0137. 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
How to Check Automatic
Transmission Fluid
It is not necessary to check the
transmission fluid level.
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 CTS/CTS-V Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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VEHICLE CARE 267
The vehicle is not equipped with a
transmission fluid level dipstick.
There is a special procedure for
checking and changing the
transmission fluid. Because this
procedure is difficult, this should be
done at the dealer. Contact your dealer
for additional information.
Change the fluid and filter at the
intervals listed inMaintenance
Schedule 0339, and be sure to use the
fluid listed in Recommended Fluids and
Lubricants 0348.
Engine Air Cleaner/Filter
The engine air cleaner/filter is in the
engine compartment on the driver
side of the vehicle. See Engine
Compartment Overview 0256.
When to Inspect the Engine Air
Cleaner/Filter
For intervals on changing and
inspecting the engine air cleaner/filter,
see Maintenance Schedule 0339.
How to Inspect the Engine Air
Cleaner/Filter
Do not start the engine or have the
engine running with the engine air
cleaner/filter housing open. Before
removing the engine air cleaner/filter,
make sure that the engine air cleaner/
filter housing and nearby components
are free of dirt and debris. Remove the
engine air cleaner/filter. Lightly tap
and shake the engine air cleaner/filter
(away from the vehicle), to release
loose dust and dirt. Inspect the engine
air cleaner/filter for damage, and
replace if damaged. Do not clean the
engine air cleaner/filter or
components with water or
compressed air.
To inspect or replace the air cleaner/
filter:
2.0L L4 Engine (LTG) Shown, 3.6L
V6 Engine (LGX) Similar
1. Remove the four screws on top of the air cleaner/filter cover.
2. Lift the air/cleaner/filter cover away from the air cleaner/filter
housing.
3. Pull out the air cleaner/filter.
4. Inspect or replace the air cleaner/filter.
5. Reverse Steps 1–3 to reinstall the air cleaner/filter cover.

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3.6L V6 Engine (LF3)
1. Engine Coolant Surge Tankand Pressure Cap
2. Engine Cooling Fan (Out of View)
6.2L V8 Engine (LT4)
1. Engine Coolant Surge Tank
and Pressure Cap
2. Engine Cooling Fan (Out of View)
{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 cooling system in the vehicle is
filled with DEX-COOL engine coolant.
See Maintenance Schedule 0339 and
Recommended Fluids and Lubricants
0 348.
The following explains the cooling
system and how to check and add
coolant when it is low. If there is a
problem with engine overheating, see
Engine Overheating 0274.

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VEHICLE CARE 271
What to Use
{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.
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 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. It is normal to see coolant moving in
the upper coolant hose return line
when the engine is running. It is also
normal to see bubbles entering the
surge tank through the small hose.
Check to see if coolant is visible in the
coolant surge tank. If the coolant
inside the coolant 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 indicated
mark, add a 50/50 mixture of clean
drinkable water and DEX-COOL
coolant.

Cadillac CTS/CTS-V Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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Be sure the cooling system is cool
before this is done.
It is normal for the coolant level in
the bottom chamber to rise and fall
with operating temperature and
ambient conditions. Coolant will
evaporate from the bottom chamber
in normal operation. This will happen
faster when the vehicle is driven for
long periods in hot, dry conditions.
If no coolant is visible in the coolant
surge tank, add coolant as follows:
How to Add Coolant to the
Coolant Surge Tank
{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.
{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
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.
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.
If no problem is found, check to see if
coolant is visible in the coolant surge
tank. If coolant is visible but the
coolant level is not at the bottom of
the fill neck, add a 50/50 mixture of
clean, drinkable water and DEX-COOL
coolant at the coolant surge tank, but
be sure the cooling system, including
the coolant surge tank pressure cap, is
cool before you do it.

Cadillac CTS/CTS-V Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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VEHICLE CARE 273
1. Remove the coolant surge tankpressure cap from the top
chamber when the cooling
system, including the coolant
surge tank pressure cap and
upper radiator hose, is no
longer hot.
Turn the pressure cap slowly
counterclockwise. If you hear a
hiss, wait for that to stop. This
will allow any pressure still left
to be vented out the
discharge hose.
2. Keep turning the pressure cap slowly and remove it. Open the
surge tank service port cap to
the lower chamber. The service
port is behind the top chamber.
3. Fill the surge tank top chamberwith the proper mixture to the
bottom of the fill neck. The top
chamber needs to be completely
full. Fill the surge tank bottom
chamber through the service port
to approximately half.
4. With the coolant surge tank pressure cap off and the surge
tank service port cap open, start
the engine and let it run until
you can feel the upper radiator
hose getting hot. Watch out for
the engine cooling fan(s).
By this time, the coolant level
inside the coolant surge tank top
chamber may be lower. If the level is lower, add more of the
proper mixture to the surge tank
top chamber until the level
reaches the bottom of the
fill neck.
5. Replace the surge tank pressure cap tightly and close the surge
tank service port cap.
6. Check the level in the surge tank top and bottom chambers when
the cooling system has cooled
down. If the coolant is not at the
proper levels, repeat Steps 1–
6 and reinstall the pressure cap
and close the service port. If the
coolant still is not at the proper
levels when the system cools
down again, see your dealer.
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.