2023 CADILLAC CT5 check engine

Cadillac CT5 Owner Manual (GMNA-Localizing-U.S./Canada-16500419) -
2023 - CRC - 5/6/22
Vehicle Care 383
1. Windshield Washer FluidReservoir. See Washer
Fluid 0399.
2. Engine Coolant Surge Tank and Pressure Cap. See
Cooling System 0392.
3. Engine Air Cleaner/Filter 0389.
4. Engine Oil Dipstick. See Engine Oil 0383.
5. Engine Cooling Fan (Out of View). See Cooling System
0392.
6. Engine Oil Fill Cap. See Engine Oil 0383.
7. Remote Positive (+) Battery Terminal. See
Jump Starting - North
America 0452.
8. Brake/Clutch Fluid Reservoir. See Brake Fluid
0404.
9. Remote Negative (-) Battery Terminal. See
Jump Starting - North
America 0452.
10. Engine Compartment Fuse Block 0412.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 0386.
.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
Overview0378 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

Cadillac CT5 Owner Manual (GMNA-Localizing-U.S./Canada-16500419) -
2023 - CRC - 5/6/22
384 Vehicle Care
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.
.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 (LSY) Engine
3.0L V6 Twin Turbo (LGY)
and 6.2L V8 (LT4) Engines
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
0 482.
Caution
Do not add too much oil. Oil
levels above or below the
acceptable operating range
shown on the dipstick are
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Caution (Continued)
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 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 0378 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.

Cadillac CT5 Owner Manual (GMNA-Localizing-U.S./Canada-16500419) -
2023 - CRC - 5/6/22
Vehicle Care 387
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 oilchange. 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)
(Base Level) 0136 or
Driver Information Center
(DIC) (Uplevel) 0139.
2. Press and hold the thumbwheel on the
steering wheel. When the
confirmation message
displays, select YES. The
oil life will change to 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. Using the DIC buttons, display REMAINING OIL
LIFE on the DIC. See Driver
Information Center (DIC)
(Base Level) 0136 or
Driver Information Center
(DIC) (Uplevel) 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.

Cadillac CT5 Owner Manual (GMNA-Localizing-U.S./Canada-16500419) -
2023 - CRC - 5/6/22
388 Vehicle Care
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.
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.
Caution
Use of the incorrect
automatic transmission fluid
may damage the vehicle, and(Continued)
Caution (Continued)
the damage may not be
covered by the vehicle
warranty. Always use the
correct automatic
transmission fluid. See
Recommended Fluids and
Lubricants0476.
Change the fluid and filter at
the intervals listed in
Maintenance Schedule 0471,
and be sure to use the fluid
listed in Recommended Fluids
and Lubricants 0476.
Manual Transmission
Fluid
It is not necessary to check
the manual 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. See Recommended
Fluids and Lubricants 0476
for the proper fluid to use.
Hydraulic Clutch
For vehicles with a manual
transmission, it is not
necessary to regularly check
brake/clutch fluid unless there
is a leak suspected. Adding
fluid will not correct a leak.
A fluid loss in this system
could indicate a problem. Have
the system inspected and
repaired.
When to Check and What
to Use
The brake/hydraulic clutch
fluid reservoir cap has this
symbol on it. See Engine
Compartment Overview 0378
for reservoir location. The
common hydraulic clutch and
brake master cylinder fluid
reservoir is filled with brake

Cadillac CT5 Owner Manual (GMNA-Localizing-U.S./Canada-16500419) -
2023 - CRC - 5/6/22
Vehicle Care 389
fluid as indicated on the
reservoir cap. See Brake Fluid
0404 for brake fluid to use.
How to Check and Add
Fluid
Visually check the brake/
clutch fluid reservoir to make
sure the fluid level is at the
MIN (minimum) line on the side
of the reservoir. The brake/
hydraulic clutch fluid system
should be closed and sealed.
Do not remove the cap to
check the fluid level or to
top-off the fluid level. Remove
the cap only when necessary
to add the proper fluid until
the level reaches the MIN line.
Engine Air Filter Life
System
This feature provides the
engine air filter’s remaining life
and best timing for a change.
The timing to change an
engine air filter depends on
driving and environmental
conditions.
When to Change the
Engine Air Filter
When the Driver Information
Center (DIC) displays a
message to replace the engine
air filter at the next oil change,
follow this timing.
When the DIC displays a
message to replace the engine
air filter soon, replace the
engine air filter at the earliest
convenience.
The system must be reset
after the engine air filter is
changed.
If the DIC displays a message
to check the engine air filter
system, see your dealer.
How to Reset the Engine
Air Filter Life System
To reset:
1. Place the vehicle in P (Park). 2. Display the Air Filter Life
on the DIC. See Driver
Information Center (DIC)
(Base Level) 0136 or
Driver Information Center
(DIC) (Uplevel) 0139.
3. Press
Ton the steering
wheel, or press the trip
odometer reset stem if the
vehicle does not have DIC
controls, to move to the
Reset/Disable display area.
Select Reset, then press
the thumbwheel or press
the reset stem for several
seconds.
4. Press the thumbwheel or the reset stem to confirm
the reset.
Engine Air Cleaner/
Filter
The engine air cleaner/filter is
in the engine compartment on
the passenger side of the
vehicle for the 2.0L L4 and
6.2L V8 engines, and in the
center of the engine

Cadillac CT5 Owner Manual (GMNA-Localizing-U.S./Canada-16500419) -
2023 - CRC - 5/6/22
394 Vehicle Care
Engine Coolant
The cooling system in the
vehicle is filled with
DEX-COOL engine coolant.
See Maintenance Schedule
0471 and
Recommended Fluids and
Lubricants 0476.
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 0398.
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
(Continued)
Caution (Continued)
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.

Cadillac CT5 Owner Manual (GMNA-Localizing-U.S./Canada-16500419) -
2023 - CRC - 5/6/22
Vehicle Care 395
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.
Be sure the cooling system is
cool before this is done.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.

Cadillac CT5 Owner Manual (GMNA-Localizing-U.S./Canada-16500419) -
2023 - CRC - 5/6/22
396 Vehicle Care
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 or above
the indicated mark, 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.
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 to the 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 0267.
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.