2021 CADILLAC CT4 cooling

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
LIGHTING 133
A high electrical load occurs when
several of the following are on, such
as: headlamps, high beams, fog lamps,
rear window defogger, climate control
fan at high speed, heated seats, engine
cooling fans, and loads plugged into
accessory power outlets.
EPM works to prevent excessive
discharge of the battery. It does this
by balancing the generator's output
and the vehicle's electrical needs.
It can increase engine idle speed to
generate more power, whenever
needed. It can temporarily reduce the
power demands of some accessories.
Normally, these actions occur in steps
or levels, without being noticeable. In
rare cases at the highest levels of
corrective action, this action may be
noticeable to the driver. If so, a DIC
message might be displayed. If a
battery message is displayed, it is
recommended that the driver reduce
the electrical loads as much as
possible. SeeDriver Information Center
(DIC) (Base Level) 0107 or
Driver Information Center (DIC)
(Uplevel) 0110.Battery Power Protection
The battery saver feature is designed
to protect the vehicle's battery.
If some interior lamps are left on and
the ignition is turned off, the battery
rundown protection system
automatically turns the lamp off after
some time.
Exterior Lighting Battery
Saver
The exterior lamps turn off about
10 minutes after the ignition is turned
off, if the parking lamps or headlamps
have been manually left on. This
protects against draining the battery.
To restart the 10-minute timer, turn
the exterior lamp control to the
O
position and then back to the;or
2position.
To keep the lamps on for more than
10 minutes, the ignition must be on or
in ACC/ACCESSORY.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
196 CLIMATE CONTROLS
Climate Controls
Climate Control Systems
Dual Automatic Climate ControlSystem . . . . . . . . . . . . . . . . . . . . . . . . . . 196
Air Vents
Air Vents . . . . . . . . . . . . . . . . . . . . . . . . . . 200
Maintenance
Passenger Compartment AirFilter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201
Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201
Climate Control Systems
Dual Automatic Climate Control System
The climate control buttons on the center stack and on the climate control
display are used to adjust the heating, cooling, and ventilation system. Center
Stack Climate Controls
1. ON/OFF (Power)
2. AUTO (Automatic Operation)
3. Air Delivery Mode Control
4. Driver Temperature Controls
5. Fan Control
6. Passenger Temperature Controls7. A/C (Air Conditioning)
8. Recirculation
9. SYNC (Synchronized Temperature)
10. Defrost
11. Rear Window Defogger

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
DRIVING AND OPERATING 207
Track Events and
Competitive Driving
(V-Series Only)
{Danger
High-performance features are
intended for use only on closed
tracks by experienced and qualified
drivers and should not be used on
public roads. High-speed driving,
aggressive cornering, hard braking,
and other high-performance driving
can be dangerous. Improper driver
inputs for the conditions may result
in loss of control of the vehicle,
which could injure or kill you or
others. Always drive safely.
Track events and competitive driving
may affect the vehicle warranty. See
the warranty manual before using the
vehicle for competitive driving.
{Warning
Prior to each track event and again
before returning to public roads,
tighten the wheel nuts with a
torque wrench to the proper torque
specification. Wheel nuts that are
improperly or incorrectly tightened
can cause the wheels to become
loose or come off, resulting in a
crash. See Capacities and
Specifications 0396 for wheel nut
torque specifications.
Caution
Low oil levels can damage the
engine. If using the vehicle for
competitive driving, the engine may
use more oil than it would with
normal use. Check the oil level
often during competitive driving.
Competitive Driving Mode can be
selected. See Driver Mode Control
0 241.
Axle Fluid
Axles must have 2400 km (1500 mi)
before being used in track driving.
The rear axle fluid temperatures may
be higher than when driving in severe
conditions. Drain and refill with new
fluid after the first racing or
competitive driving event, and then
after every 24 hours of racing or
competitive driving. See Recommended
Fluids and Lubricants 0391.
Caution
During a first time track or racing
event, high axle temperatures can
occur. Damage could be caused to
the axle and would not be covered
by the vehicle warranty. Do not
drive as long or as fast the first
time the vehicle is driven on the
track or raced.
.The axle lubricant should be
replaced with new lubricant.
.Additional cooling capacity is also
required for continuous competitive
driving.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
208 DRIVING AND OPERATING
Engine Oil
Check the oil level often during track
events and competitive driving and
keep the oil level at or near the
upper mark.
Fuel
Use premium unleaded gasoline with
a posted octane rating of 93 at a track
event. Unleaded gasoline with a
posted octane rating of 91 may be
used, but performance will be
degraded.
Automatic Transmission Fluid
Have the transmission fluid set to the
track specific oil level prior to track
usage. Transmission fluid should be
changed after every 15 hours of track
usage. Any transmission level set or
change should be performed at your
dealer.
Brakes
Brake cooling can be improved if the
front brake disc splash shield and
front tire deflector are removed.
Removing the shield will require that
the suspension bushings and wheelspeed wires visible to the brake disc
be protected with insulated thermal
wrapping.
Caution
Removing the splash shield can
degrade wet braking performance,
as well as introduce brake pedal
pulsation, due to brake disc
exposure to road debris. Only
remove the front brake disc splash
shield and front tire deflector when
driving in track events.
Brake Pad Wear Sensors
(V-Series Only)
If equipped, the brake pad wear
sensors need to be removed from the
brake calipers prior to any track or
racing event. The original sensors can
be reinstalled if significant brake pad
wear is not observed. The sensor
should not extend beyond the brake
pad surface at the rotor contact.
If this condition is observed, the brake
pad life system needs to be disabled
until a new set of brake pads and
sensors are installed and the system
reset. Brake Fluid
.Before racing, replace existing brake
fluid with a qualified racing brake
fluid from a sealed container. Brake
fluid with a dry boiling point
>279 °C (534 °F) is qualified.
If racing brake fluid is used, replace
it with GM approved brake fluid
before driving on public roads. See
Recommended Fluids and Lubricants
0
391.
.Do not use silicone-based fluids.
If racing brake fluid is in the vehicle
and the age of the brake fluid is over a
month old or unknown, replace the
brake fluid between racing/closed
track driving.
Caution
Failure to change the brake fluid
and transfer case fluid after any
performance or race track driving
could result in damage not covered
by the vehicle warranty. Have the
brake fluid and transfer case fluid
changed by your dealer after any (Continued)

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
212 DRIVING AND OPERATING
{Warning
Wet brakes can cause crashes. They
might not work as well in a quick
stop and could cause pulling to one
side. You could lose control of the
vehicle.
After driving through a large puddle
of water or a car/vehicle wash,
lightly apply the brake pedal until
the brakes work normally.
Flowing or rushing water creates
strong forces. Driving through
flowing water could cause the
vehicle to be carried away. If this
happens, you and other vehicle
occupants could drown. Do not
ignore police warnings and be very
cautious about trying to drive
through flowing water.
Hydroplaning
Hydroplaning is dangerous. Water can
build up under the vehicle's tires so
they actually ride on the water. This
can happen if the road is wet enoughand you are going fast enough. When
the vehicle is hydroplaning, it has
little or no contact with the road.
There is no hard and fast rule about
hydroplaning. The best advice is to
slow down when the road is wet.
Other Rainy Weather Tips
Besides slowing down, other wet
weather driving tips include:
.Allow extra following distance.
.Pass with caution.
.Keep windshield wiping equipment
in good shape.
.Keep the windshield washer fluid
reservoir filled.
.Have good tires with proper tread
depth. See
Tires0339.
.Turn off cruise control.
Hill and Mountain Roads
Driving on steep hills or through
mountains is different than driving on
flat or rolling terrain. Tips include:
.Keep the vehicle serviced and in
good shape.
.Check all fluid levels and brakes,
tires, cooling system, and
transmission.
.Shift to a lower gear when going
down steep or long hills.
{Warning
Using the brakes to slow the vehicle
on a long downhill slope can cause
brake overheating, can reduce brake
performance, and could result in a
loss of braking. Shift the
transmission to a lower gear to let
the engine assist the brakes on a
steep downhill slope.
{Warning
Coasting downhill in N (Neutral) or
with the ignition off is dangerous.
This can cause overheating of the
brakes and loss of steering assist.
Always have the engine running
and the vehicle in gear.
.Drive at speeds that keep the
vehicle in its own lane. Do not
swing wide or cross the center line.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
300 DRIVING AND OPERATING
When towing at higher altitudes,
engine coolant will boil at a lower
temperature than at lower altitudes.
If the engine is turned off immediately
after towing at high altitude on steep
uphill grades, the vehicle could show
signs similar to engine overheating. To
avoid this, let the engine run,
preferably on level ground, with the
transmission in P (Park) for a few
minutes before turning the engine off.
If the overheat warning comes on, see
Engine Overheating0322.
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 a 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 0380. 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
0 322.
Trailer Towing (LSY 2.0L L4
Engine)
Caution
Towing a trailer improperly can
damage the vehicle and result in
costly repairs not covered by the
vehicle warranty. To tow a trailer
correctly, follow the directions in
this section and see your dealer for
important information about
towing a trailer with the vehicle.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
304 VEHICLE CARE
Vehicle Care
General Information
General Information . . . . . . . . . . . . . 305
California Proposition65 Warning . . . . . . . . . . . . . . . . . . . . . 305
California Perchlorate Materials Requirements . . . . . . . . . . . . . . . . . . . 306
Accessories and Modifications . . . . . . . . . . . . . . . . . . . 306
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . . . . . . 306
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . . . . . . 309
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . 312
Engine Oil Life System . . . . . . . . . . . 314
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315
Engine Air Filter Life System . . . . 315
Engine Air Cleaner/Filter . . . . . . . . . 316
Cooling System . . . . . . . . . . . . . . . . . . . 317
Engine Overheating . . . . . . . . . . . . . . 322
Washer Fluid . . . . . . . . . . . . . . . . . . . . . 323
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323 Brake Pad Life System (If
Equipped) . . . . . . . . . . . . . . . . . . . . . . . 324
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . 325
Battery - North America . . . . . . . . . 326
All-Wheel Drive . . . . . . . . . . . . . . . . . . 327
Park Brake and P (Park) Mechanism Check . . . . . . . . . . . . . . 327
Wiper Blade Replacement . . . . . . . 327
Windshield Replacement . . . . . . . . 328
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . 328
Headlamp Aiming
Front Headlamp Aiming . . . . . . . . . 329
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . . . . . 329
Halogen Bulbs . . . . . . . . . . . . . . . . . . . . 330
High Intensity Discharge (HID) Lighting . . . . . . . . . . . . . . . . . . . . . . . . . 330
LED Lighting . . . . . . . . . . . . . . . . . . . . . 330
Front Turn Signal Lamps . . . . . . . . 330
Electrical System
Electrical System Overload . . . . . . 330
Fuses and Circuit Breakers . . . . . . 331
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332
Instrument Panel Fuse Block . . . . 334
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339
All-Season Tires . . . . . . . . . . . . . . . . . . 339
Winter Tires . . . . . . . . . . . . . . . . . . . . . . 340
Run-Flat Tires . . . . . . . . . . . . . . . . . . . . 340
Self-Sealing Tires . . . . . . . . . . . . . . . . . 341
Low-Profile Tires . . . . . . . . . . . . . . . . . 341
Summer Tires . . . . . . . . . . . . . . . . . . . . 341
Tire Sidewall Labeling . . . . . . . . . . . 342
Tire Designations . . . . . . . . . . . . . . . . . 343
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . . . . . . . 344
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . 346
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . . . . . . 347
Tire Pressure Monitor System . . . 348
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . . . . . . . . 349
Tire Inspection . . . . . . . . . . . . . . . . . . . 352
Tire Rotation . . . . . . . . . . . . . . . . . . . . . 352
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353
Buying New Tires . . . . . . . . . . . . . . . . 354
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . . . . . . . . 356
Uniform Tire Quality Grading . . . 356
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . . . . . . . . 357

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
310 VEHICLE CARE
1. Windshield Washer Fluid Reservoir.See Washer Fluid 0323.
2. Engine Coolant Surge Tank and Pressure Cap. See Cooling System
0 317.
3. Engine Air Cleaner/Filter 0316.
4. Engine Cooling Fan (Out of View). See Cooling System 0317.
5. Engine Oil Fill Cap. See Engine Oil
0 312.
6. Engine Oil Dipstick. See Engine Oil
0 312.
7. Remote Positive (+) Battery Terminal. See Jump Starting - North
America 0366.
8. Brake Fluid Reservoir. See Brake
Fluid 0325.
9. Remote Negative (-) Battery Terminal. See Jump Starting - North
America 0366.
10. Engine Compartment Fuse Block
0332.