check engine CADILLAC CT5 2021 Owner's Guide

Cadillac CT5 Owner Manual (GMNA-Localizing-U.S./Canada-14584312) -
2021 - CRC - 11/23/20
VEHICLE CARE 325
2.0L L4 Engine
Automatic Coolant Service Fill
Instructions
The vehicle is equipped with a service
feature that assists with filling and
removing air from the cooling system
after service of components or when
coolant is added after being too low.
To use the service feature:
1. With a cold system, add coolant tothe indicated line on the
surge tank.
2. Replace the pressure cap on the surge tank. To activate the service feature:
1. Connect the vehicle to a battery charger.
2. Turn the ignition on. See Ignition
Positions 0224.
3. Turn off the air conditioning.
4. Set the parking brake.
5. At the same time, press the accelerator and the brake pedal for
two seconds, then release.
6. At the end of the cycle, check the coolant level in the surge tank and
add coolant if it is below the
indicated line. Turn the ignition
off, allow the Electronic Control
Module (ECM) to go to sleep, about
two minutes, and repeat Steps 2–6.
Listen for pump activation and
movement of the control valves while
watching the level of the coolant in
the surge tank. If the tank empties,
turn the ignition off, carefully remove
the pressure cap, refill to the indicated
line, replace the pressure cap, and
repeat Steps 2–6.
The fill and air removal process will
run for approximately 15 minutes.
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.
3.0L V6 Engine
1. Remove the coolant surge tank pressure cap 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.

Cadillac CT5 Owner Manual (GMNA-Localizing-U.S./Canada-14584312) -
2021 - CRC - 11/23/20
326 VEHICLE CARE
3. Fill the surge tank with the propermixture to the indicated
level mark.
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 fan.
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
surge tank until the level reaches
the indicated level mark.
5. Replace the pressure cap tightly. 6. Check the level in the surge tank
after the engine is shut off and the
cooling system has cooled down.
If the coolant is not at the proper
level, repeat Steps 1–6. If the
coolant still is not at the proper
level 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.
Engine Overheating
The vehicle has an indicator to warn
of the engine overheating.
If the decision is made not to lift the
hood when this warning appears, get
service help right away. See Roadside
Service 0405.
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 fan is running. If the engine is
overheating, the fan should be running. If it is 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 CT5 Owner Manual (GMNA-Localizing-U.S./Canada-14584312) -
2021 - CRC - 11/23/20
VEHICLE CARE 327
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.
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 overheat warning no longer
displays, the vehicle can be driven.
Continue to drive the vehicle slowly
for about 10 minutes. Keep a safe
vehicle distance from the vehicle in
front. 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.Washer Fluid
What to Use
When windshield washer fluid is
needed, be sure to read the
manufacturer's instructions before
use. If operating the vehicle in an area
where the temperature may fall below
freezing, use a fluid that has sufficient
protection against freezing.
Adding Washer Fluid
Open the cap with the washer symbol
on it. Add washer fluid until the tank
is full. See
Engine Compartment
Overview 0313 for reservoir location.
Caution
.Do not use washer fluid that
contains any type of water
repellent coating. This can cause
the wiper blades to chatter
or skip.
.Do not use engine coolant
(antifreeze) in the windshield
washer. It can damage the
windshield washer system and
paint.
.Do not mix water with
ready-to-use washer fluid. Water
can cause the solution to freeze
and damage the washer fluid
tank and other parts of the
washer system.
.When using concentrated washer
fluid, follow the manufacturer
instructions for adding water.
.Fill the washer fluid tank only
three-quarters full when it is very
cold. This allows for fluid
(Continued)

Cadillac CT5 Owner Manual (GMNA-Localizing-U.S./Canada-14584312) -
2021 - CRC - 11/23/20
VEHICLE CARE 329
How to Reset the Brake Pad Life
System
The system will automatically detect
when significantly worn brake pads
and sensors are replaced. When the
ignition is turned on after new pads
and sensors are installed, a message
will display. Follow the prompts to
reset the system.
The brake pad life system can also be
manually reset:1. Display Brake Pad Life on the DIC. See Driver Information Center (DIC)
(Base Level) 0113 or
Driver Information Center (DIC)
(Uplevel) 0116.
2. Press the thumbwheel. Select front or rear pads as appropriate.
3. Select YES on the confirmation message. Repeat for pads on the
other axle if they were also
replaced.
How to Disable the Brake Pad
Life System
The brake pad life system can be
turned off. This may be necessary if
aftermarket brake pads without wear sensors are installed. When the
system is turned off, the front and
rear brake pad life percentages will
not display. However, the built-in wear
indicators that make a high-pitched
warning sound when the brake pads
are worn can still determine when the
pads should be replaced. See
Brakes
0 328.
To turn off the brake pad life system: 1. Display Brake Pad Life on the DIC. See Driver Information Center (DIC)
(Base Level) 0113 or
Driver Information Center (DIC)
(Uplevel) 0116.
2. Select DISABLE.
To turn the brake pad life system back
on, follow the above steps but select
ENABLE in Step 2.
Brake Fluid
The brake master cylinder reservoir is
filled with GM approved DOT 4 brake
fluid as indicated on the reservoir cap.
See Engine Compartment Overview
0 313 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

Cadillac CT5 Owner Manual (GMNA-Localizing-U.S./Canada-14584312) -
2021 - CRC - 11/23/20
VEHICLE CARE 331
Warning (Continued)
more information go to
www.P65Warnings.ca.gov/
passenger-vehicle.
See California Proposition 65 Warning
0 309 and the back cover.
Vehicle Storage
{Warning
Batteries have acid that can burn
you and gas that can explode. You
can be badly hurt if you are not
careful. See Jump Starting - North
America 0368 for tips on working
around a battery without
getting hurt.
Infrequent Usage: Remove the black,
negative (−) cable from the battery to
keep the battery from running down.
Extended Storage: Remove the black,
negative (−) cable from the battery or
use a battery trickle charger.
All-Wheel Drive
If the vehicle is equipped with
All-Wheel-Drive (AWD), this is an
additional system that needs
lubrication.
Transfer Case
Under normal driving conditions,
transfer case fluid does not require
maintenance unless there is a fluid
leak or unusual noise. If required,
have the transfer case serviced by
your dealer.
Park Brake and P (Park)
Mechanism Check
{Warning
When you are doing this check, the
vehicle could begin to move. You or
others could be injured and
property could be damaged. Make
sure there is room in front of the
vehicle in case it begins to roll. Be
ready to apply the regular brake at
once should the vehicle begin
to move. Park on a fairly steep hill, with the
vehicle facing downhill. Keeping your
foot on the regular brake, set the
parking brake.
.To check the parking brake's
holding ability: With the engine
running and the transmission in
N (Neutral), slowly remove foot
pressure from the regular brake
pedal. Do this until the vehicle is
held by the parking brake only.
.To check the P (Park) mechanism's
holding ability: With the engine
running, shift to P (Park). Then
release the parking brake followed
by the regular brake.
Contact your dealer if service is
required.
Wiper Blade Replacement
Windshield wiper blades should be
inspected for wear or cracking.
It is a good idea to clean or replace
the wiper blade assembly on a regular
basis or when worn. For proper
windshield wiper blade length and
type, see Maintenance Replacement
Parts 0393.

Cadillac CT5 Owner Manual (GMNA-Localizing-U.S./Canada-14584312) -
2021 - CRC - 11/23/20
VEHICLE CARE 335
{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.
{Warning
Installation or use of fuses that do
not meet GM’s original fuse
specifications is dangerous. The
fuses could fail, and result in a fire.
You or others could be injured or
killed, and the vehicle could be
damaged.See
Accessories and Modifications
0 310 and
General Information 0309.
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
The engine compartment fuse block is
on the driver side of the engine
compartment.
Lift the fuse block cover to access the
fuses.
The vehicle may not be equipped with
all of the fuses and relays shown.
Caution
Spilling liquid on any electrical
component on the vehicle may
damage it. Always keep the covers
on any electrical component.

Cadillac CT5 Owner Manual (GMNA-Localizing-U.S./Canada-14584312) -
2021 - CRC - 11/23/20
VEHICLE CARE 375
Air Intakes
Clear debris from the air intakes
between the hood and windshield
when washing the vehicle.
Shutter System
The vehicle may have a shutter
system designed to help improve fuel
economy. Keep the shutter system
clear of debris, snow and ice. If the
check engine light is activated, please
check to see if the shutter system is
clear of debris, snow or ice.
Windshield and Wiper Blades
Clean the outside of the windshield
with glass cleaner.Clean rubber blades using a lint-free
cloth or paper towel soaked with
windshield washer fluid or a mild
detergent. Wash the windshield
thoroughly when cleaning the blades.
Bugs, road grime, sap, and a buildup
of vehicle wash/wax treatments may
cause wiper streaking.
Replace the wiper blades if they are
worn or damaged. Damage can be
caused by extreme dusty conditions,
sand, salt, heat, sun, snow, and ice.
Weatherstrips
Apply weatherstrip lubricant on
weatherstrips to make them last
longer, seal better, and not stick or
squeak. Lubricate weatherstrips at
least once a year. Hot, dry climates
may require more frequent
application. Black marks from rubber
material on painted surfaces can be
removed by rubbing with a clean
cloth. See
Recommended Fluids and
Lubricants 0392.
Tires
Use a stiff brush with tire cleaner to
clean the tires.
Caution
Using petroleum-based tire dressing
products on the vehicle may
damage the paint finish and/or
tires. When applying a tire dressing,
always wipe off any overspray from
all painted surfaces on the vehicle.
Wheels and Wheel Trim
Use a soft, clean cloth with mild soap
and water to clean the wheels. After
rinsing thoroughly with clean water,
dry with a soft, clean towel. A wax
may then be applied.
Caution
Chrome wheels and chrome wheel
trim may be damaged if the vehicle
is not washed after driving on roads
that have been sprayed with
magnesium chloride or calcium
chloride. These are used on roads
for conditions such as dust and ice.
Always wash the chrome with soap
and water after exposure.

Cadillac CT5 Owner Manual (GMNA-Localizing-U.S./Canada-14584312) -
2021 - CRC - 11/23/20
382 SERVICE AND MAINTENANCE
The Tire Rotation and Required
Services are the responsibility of the
vehicle owner. It is recommended to
have your dealer perform these
services every 12 000 km/7,500 mi.
Proper vehicle maintenance helps to
keep the vehicle in good working
condition, improves fuel economy, and
reduces vehicle emissions.
Because of the way people use
vehicles, maintenance needs vary.
There may need to be more frequent
checks and services. The Additional
Required Services - Normal are for
vehicles that:
.Carry passengers and cargo within
recommended limits on the Tire
and Loading Information label. See
Vehicle Load Limits0219.
.Are driven on reasonable road
surfaces within legal driving limits.
.Use the recommended fuel. See
Recommended Fuel (LSY 2.0L L4
Engine) 0297 or
Recommended Fuel (LGY 3.0L
V6 Engine) 0297.
Refer to the information in the
Maintenance Schedule Additional
Required Services - Normal chart.
The Additional Required Services -
Severe are for vehicles that are:
.Mainly driven in heavy city traffic
in hot weather.
.Mainly driven in hilly or
mountainous terrain.
.Frequently towing a trailer.
.Used for high speed or competitive
driving.
.Used for taxi, police, or delivery
service. Refer to the information in the
Maintenance Schedule Additional
Required Services - Severe chart.
{Warning
Performing maintenance work can
be dangerous and can cause serious
injury. Perform maintenance work
only if the required information,
proper tools, and equipment are
available. If they are not, see your
dealer to have a trained technician
do the work. See
Doing Your Own
Service Work 0310.

Cadillac CT5 Owner Manual (GMNA-Localizing-U.S./Canada-14584312) -
2021 - CRC - 11/23/20
SERVICE AND MAINTENANCE 383
Maintenance Schedule
Owner Checks and Services
Check the engine oil level. SeeEngine
Oil 0316.
Once a Month
.Check the tire inflation pressures.
See Tire Pressure 0349.
.Inspect the tires for wear. See Tire
Inspection 0355.
.Check the windshield washer fluid
level. See Washer Fluid 0327.
Engine Oil Change
When the CHANGE ENGINE OIL
SOON message displays, have the
engine oil and filter changed within
the next 1 000 km (600 mi). If driven
under the best conditions, the engine
oil life system may not indicate the
need for vehicle service for up to a
year. The engine oil and filter must be
changed at least once a year and the
oil life system must be reset. Your
trained dealer technician can perform
this work. If the engine oil life system
is reset accidentally, service the vehicle within 5 000 km (3,000 mi)
since the last service. Reset the oil life
system when the oil is changed. See
Engine Oil Life System
0318.
Air Conditioning Desiccant
(Replace Every Seven Years)
The air conditioning system requires
maintenance every seven years. This
service requires replacement of the
desiccant to help the longevity and
efficient operation of the air
conditioning system. This service can
be complex. See your dealer.
Tire Rotation and Required
Services Every 12 000 km
(7,500 mi)
Rotate the tires, if recommended for
the vehicle, and perform the following
services. See Tire Rotation0355.
.Check engine oil level and oil
life percentage. If needed, change
engine oil and filter, and reset oil
life system. See Engine Oil0316 and
Engine Oil Life System 0318.
.If equipped, check the air filter
life percentage. If necessary, replace
the engine air filter and reset the
engine air filter life system. See
Engine Air Filter Life System 0319.
If the vehicle is not equipped with
the engine air filter life system,
inspect the engine air cleaner filter.
See Engine Air Cleaner/Filter 0320.
.Check engine coolant level. See
Cooling System 0322.
.Check windshield washer fluid level.
See Washer Fluid 0327.
.Check tire inflation pressures. See
Tire Pressure 0349.
.Inspect tire wear. See Tire Inspection
0 355.
.Visually check for fluid leaks.
.Inspect brake system. See Exterior
Care 0372.
.Visually inspect steering,
suspension, and chassis
components for damage, including
cracks or tears in the rubber boots,
loose or missing parts, or signs of
wear at least once a year. See
Exterior Care 0372.

Cadillac CT5 Owner Manual (GMNA-Localizing-U.S./Canada-14584312) -
2021 - CRC - 11/23/20
SERVICE AND MAINTENANCE 385
Maintenance Schedule
Additional Required Services -
Normal12 000 km/7,500 mi
24 000 km/15,000 mi
36 000 km/22,500 mi
48 000 km/30,000 mi
60 000 km/37,500 mi
72 000 km/45,000 mi
84 000 km/52,500 mi
96 000 km/60,000 mi
108 000 km/67,500 mi
120 000 km/75,000 mi
132 000 km/82,500 mi
144 000 km/90,000 mi
156 000 km/97,500 mi
168 000 km/105,000 mi
180 000 km/112,500 mi
192 000 km/120,000 mi
204 000 km/127,500 mi
216 000 km/135,000 mi
228 000 km/142,500 mi
240 000 km/150,000 mi
Rotate tires, if recommended for the vehicle, and
perform Required Services. (1) Check engine oil level
and oil life percentage. Change engine oil and filter,
if needed.
If equipped, check engine air filter life percentage
and status. Change engine air filter, if needed.
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
Replace passenger compartment air filter. (2)@ @@@@@
If the vehicle is not equipped with the engine air
filter life system, replace engine air cleaner filter. (3)@ @@
Inspect evaporative control system. (4)@@@
Replace spark plugs. Inspect spark plug wires and/or
boots.@ @
Change transfer case fluid, if equipped with
AWD. (5)@
Change rear axle fluid, if equipped with limited slip
differential. (5)@@@
Change rear axle fluid, without limited slip
differential. (5)@
Change front axle fluid, if equipped with AWD. (5)@
Drain and fill engine cooling system. (6)@
Visually inspect accessory drive belts. (7)@
Replace brake fluid. (8)
Replace windshield wiper blades. (9)
@ @ @ @ @ @ @ @ @ @
Replace hood and/or body lift support gas
struts. (10)@ @
Replace air conditioning desiccant. (11)