2023 CADILLAC CT4 check engine

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/10/22
360 Driving and Operating
If equipped, the following
driver assistance features
should be turned to alert or
off when towing a trailer:
.Automatic Emergency
Braking (AEB)
.Intelligent Brake Assist (IBA)
.Front Pedestrian
Braking (FPB)
If equipped with Lane Change
Alert (LCA), the LCA detection
zones that extend back from
the side of the vehicle do not
move further back when a
trailer is towed. Use caution
while changing lanes when
towing a trailer.
If equipped with Rear Cross
Traffic Alert (RCTA), use
caution while backing up when
towing a trailer, as the RCTA
detection zones that extend
out from the back of the
vehicle do not move further
back when a trailer is towed.
{Warning
To prevent serious injury or
death from carbon monoxide
(CO), when towing a trailer:
.Do not drive with the
liftgate, trunk/hatch,
or rear-most
window open.
.Fully open the air outlets
on or under the
instrument panel.
.Adjust the climate control
system to a setting that
brings in only outside air.
See “Climate Control
Systems” in the Index.
For more information about
carbon monoxide, see
Engine Exhaust 0271.
Towing a trailer requires
experience. The combination
of the vehicle and trailer is
longer and not as responsive
as the vehicle itself. Become
familiar with handling and braking by driving on a level
road surface before driving on
public roads.
The trailer structure, the tires,
and the brakes must be all be
rated to carry the intended
cargo. Inadequate trailer
equipment can cause the
combination to operate in an
unexpected or unsafe manner.
Before driving, inspect all
trailer hitch parts and
attachments, safety chains,
electrical connectors, lamps,
tires, and mirrors. See Towing
Equipment
0365. If the trailer
has electric brakes, start the
combination moving and then
manually apply the trailer
brake controller to check the
trailer brakes work. During the
trip, occasionally check that
the cargo and trailer are
secure and that the lamps and
any trailer brakes are working.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/10/22
362 Driving and Operating
transmission in P (Park) for a
few minutes before turning
the engine off. If the overheat
warning comes on, see Engine
Overheating0391.
Parking on Hills
{Warning
To prevent serious injury or
death, always park your
vehicle and trailer on a level
surface when possible.
When parking your vehicle and
your trailer 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, gradually
release the brake pedal to
allow the chocks to absorb
the load of the trailer.
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.
.Start the engine.
.Shift into the
desired gear.
.Release the parking
brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the
chocks.
Maintenance when Trailer
Towing
The vehicle needs service
more often when used to tow
trailers. See Maintenance
Schedule 0469. It is especially
important to check the
automatic transmission fluid,
engine oil, axle lubricant, belts,
cooling system, and brake
system before and during
each trip.
Check periodically that all nuts
and bolts on the trailer hitch
are tight.
Engine Cooling when
Trailer Towing
The cooling system may
temporarily overheat during
severe operating conditions.
See Engine Overheating 0391.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/10/22
366 Driving and Operating
Trailer Brakes
Loaded trailers over 450 kg
(1,000 lb) must be equipped
with brake systems and with
brakes for each axle. Trailer
braking equipment conforming
to Canadian Standards
Association (CSA) requirement
CAN3-D313, or its equivalent,
is recommended.
State or local regulations may
require trailers to have their
own braking system if the
loaded weight of the trailer
exceeds certain minimums
that can vary from state to
state. Read and follow the
instructions for the trailer
brakes so they are installed,
adjusted, and maintained
properly. Never attempt to tap
into your vehicle's hydraulic
brake system. If you do, both
the vehicle anti-lock brakes
and the trailer brakes may not
function, which could result in
a crash.
Trailer Lamps
Always check all trailer lamps
are working at the beginning
of each trip, and periodically
on longer trips.
Turn Signals When
Towing a Trailer
When properly connected, the
trailer turn signals will
illuminate to indicate the
vehicle is turning, changing
lanes, or stopping. When
towing a trailer, the arrows on
the instrument cluster will
illuminate even if the trailer is
not properly connected or the
bulbs are burned out.
Conversions and
Add-Ons
Add-On Electrical
Equipment
{Warning
The Data Link Connector
(DLC) is used for vehicle
service and Emission
Inspection/Maintenance
testing. See Malfunction
Indicator Lamp (Check
Engine Light)0118. 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.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
368 Vehicle Care
Vehicle Care
General Information
General Information . . . . . . 369
California PerchlorateMaterials
Requirements . . . . . . . . . . . . . 370
Accessories and Modifications . . . . . . . . . . . . . 370
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . 370
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . 371
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . 373
Engine Oil . . . . . . . . . . . . . . . . . . . . 378
Engine Oil Life System . . . 381
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 382
Manual Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 382
Hydraulic Clutch . . . . . . . . . . . 383
Engine Air Filter Life System . . . . . . . . . . . . . . . . . . . . . . 383
Engine Air Cleaner/ Filter . . . . . . . . . . . . . . . . . . . . . . . . . 384
Cooling System . . . . . . . . . . . . 386
Engine Overheating . . . . . . . 391 Washer Fluid . . . . . . . . . . . . . . . . 393
Brakes . . . . . . . . . . . . . . . . . . . . . . . . 393
Brake Pad Life System (If
Equipped) . . . . . . . . . . . . . . . . . . 396
Brake Fluid . . . . . . . . . . . . . . . . . . 398
Battery - North
America . . . . . . . . . . . . . . . . . . . . . 399
All-Wheel Drive . . . . . . . . . . . . 400
Park Brake and P (Park) Mechanism Check . . . . . . . 400
Wiper Blade Replacement . . . . . . . . . . . . . . 401
Windshield Replacement . . . . . . . . . . . . . . 401
Gas Strut(s) . . . . . . . . . . . . . . . . . 402
Headlamp Aiming
Front Headlamp Aiming . . . . . . . . . . . . . . . . . . . . . . . 403
Bulb Replacement
Bulb Replacement . . . . . . . . 403
Halogen Bulbs . . . . . . . . . . . . . . 403
High Intensity Discharge(HID) Lighting . . . . . . . . . . . . . 403
LED Lighting . . . . . . . . . . . . . . . . 403
Front Turn Signal Lamps . . . . . . . . . . . . . . . . . . . . . . . 404
Electrical System
Electrical SystemOverload . . . . . . . . . . . . . . . . . . . 404
Fuses and Circuit Breakers . . . . . . . . . . . . . . . . . . . 406
Engine Compartment
Fuse Block . . . . . . . . . . . . . . . . . 407
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 409
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . 411
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . 413
All-Season Tires . . . . . . . . . . . . 414
Winter Tires . . . . . . . . . . . . . . . . . 414
Run-Flat Tires . . . . . . . . . . . . . . . 415
Self-Sealing Tires . . . . . . . . . . 415
Low-Profile Tires . . . . . . . . . . 416
Summer Tires . . . . . . . . . . . . . . . 416
Tire Sidewall Labeling . . . . 417
Tire Designations . . . . . . . . . . 418
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . . . 419
Tire Pressure . . . . . . . . . . . . . . . 422
Tire Pressure for High-Speed
Operation . . . . . . . . . . . . . . . . . . 423
Tire Pressure Monitor System . . . . . . . . . . . . . . . . . . . . . . 424

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
378 Vehicle Care
1. Windshield Washer FluidReservoir. See Washer
Fluid 0393.
2. Engine Coolant Surge Tank and Pressure Cap. See
Cooling System 0386.
3. Engine Air Cleaner/Filter 0384.
4. Engine Cooling Fan (Out of View). See Cooling System
0386.
5. Engine Oil Fill Cap. See Engine Oil 0378.
6. Engine Oil Dipstick. See Engine Oil 0378.
7. Remote Positive (+) Battery Terminal. See
Jump Starting - North
America 0447.
8. Brake/Clutch Fluid Reservoir. See Brake Fluid
0398.
9. Remote Negative (-) Battery Terminal. See
Jump Starting - North
America 0447. 10. Engine Compartment Fuse
Block. See Engine
Compartment Fuse Block
0407.
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 0381.
.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
Overview0373 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.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Vehicle Care 379
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.
.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 and 2.7L L4 Engines
3.6L V6 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
0
480.
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 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 0373 for the
location of the engine oil
fill cap.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Vehicle Care 381
manufacturer's warnings
about the use and disposal of
oil products.
Used oil can be a threat to the
environment. If you change
your own oil, be sure to drain
all the oil from the filter before
disposal. Never dispose of oil
by putting it in the trash or
pouring it on the ground, into
sewers, or into streams or
bodies of water. Recycle it by
taking it to a place that
collects used oil.
Engine Oil Life
System
When to Change
Engine Oil
This vehicle has a computer
system that indicates when to
change the engine oil and
filter. This is based on a
combination of factors which
include engine revolutions,
engine temperature, and miles
driven. Based on driving
conditions, the mileage atwhich an oil change is
indicated can 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)
(Base Level) 0129 or
Driver Information Center
(DIC) (Uplevel) 0132.
2. Press and hold the thumbwheel on the
steering wheel. When the

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
382 Vehicle Care
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) 0129 or
Driver Information Center
(DIC) (Uplevel) 0132.
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.
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
the damage may not be
covered by the vehicle
warranty. Always use the
correct automatic
transmission fluid. See
Recommended Fluids and
Lubricants
0474.
Change the fluid and filter at
the intervals listed in
Maintenance Schedule 0469,
and be sure to use the fluid
listed in Recommended Fluids
and Lubricants 0474.
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