
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
374 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 Fluid Reservoir. See Brake Fluid 0398.
9. Remote Negative (-) Battery Terminal. See
Jump Starting - North
America 0447.
10. Engine Compartment Fuse Block 0407.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
376 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. Cooling System Air Bleeder Cap. See Cooling
System 0386.
7. Engine Oil Dipstick. See Engine Oil 0378.
8. Remote Positive (+) Battery Terminal. See
Jump Starting - North
America 0447.
9. Brake Fluid Reservoir. See Brake Fluid 0398.
10. Remote Negative (-) Battery Terminal. See
Jump Starting - North
America 0447. 11. Engine Compartment Fuse
Block. See Engine
Compartment Fuse Block
0407.

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
390 Vehicle Care
To use this feature:
1. With a cold system, addcoolant to the indicated
line on the surge tank.
2. Replace the pressure cap on the surge tank.
3. Activate the service feature:
3.1. Connect the vehicle to a battery charger.
3.2.Turn the ignition to Service Mode. See
Ignition Positions 0261.
3.3.Turn off the air conditioning. 3.4.Set the parking brake.
3.5.At the same time, press
the accelerator and the
brake pedal for
two seconds, then
release.
3.6.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 3.2 –3.6.
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 3.2 –3.6. 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.
2.7L 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 to low.
To use this feature:
1. With a cold system unscrew the cooling
system air bleeder cap.
If coolant can be seen
through the bleeder move
to Step 3.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Vehicle Care 391
2. Add coolant through thesurge tank until it is visible
through the air bleeder.
3. Replace the cooling system air bleeder cap.
4. Add coolant to the indicated line on the
surge tank.
5. Replace the pressure cap on the surge tank.
6. Activate the service feature:
6.1. Connect the vehicle to a battery charger.
6.2.Turn the ignition to Service Mode. See
Ignition Positions 0261.
6.3.Turn off the air conditioning.
6.4.Set the parking brake.
6.5.At the same time, press the accelerator and the
brake pedal for
two seconds, then
release. 6.6.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, carefully remove
the pressure cap, refill
to the indicated line,
replace the pressure
cap, and repeat steps
6.2 –6.6.
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 6.2 –6.6.
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.
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
Assistance Program 0487.
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.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Vehicle Care 399
What to Add
Use only GM approved DOT 4
brake fluid from a clean, sealed
container. See Recommended
Fluids and Lubricants0474.
{Warning
The wrong or contaminated
brake fluid could result in
damage to the brake
system. This could result in
the loss of braking leading to
a possible injury. Always use
the proper GM approved
brake fluid.
Caution
If brake fluid is spilled on the
vehicle's painted surfaces,
the paint finish can be
damaged. Immediately wash
off any painted surface.
Battery - North
America
The original equipment battery
is maintenance free. Do not
remove the cap and do not
add fluid.
Refer to the replacement
number shown on the original
battery label when a new
battery is needed.
The vehicle has an Absorbed
Glass Mat (AGM) 12-volt
battery. Installation of a
standard 12-volt battery will
result in reduced 12-volt
battery life.
When using a 12-volt battery
charger on the 12-volt AGM
battery, some chargers have
an AGM battery setting on the
charger. If available, use the
AGM setting on the charger,
to limit charge voltage to
14.8 volts. Follow the charger
manufacturer's instructions. Stop/Start System
This vehicle has a Stop/Start
system to shut off the engine
to help conserve fuel. See
Stop/Start System
0264.
{Warning
WARNING: Battery posts,
terminals and related
accessories can expose you
to chemicals including lead
and lead compounds, which
are known to the State of
California to cause cancer
and birth defects or other
reproductive harm. Wash
hands after handling. For
more information go to
www.P65Warnings.ca.gov.
See the warning on the back
cover.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
400 Vehicle Care
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
America0447 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.
.Automatic transmission
vehicles 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.