2021 CADILLAC CT4 heater

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
318 VEHICLE CARE
2.7L L4 Engine
1. Engine Coolant Surge Tank andPressure Cap
2. Engine Cooling Fan (Out of View)
3. Cooling System Air Bleeder Cap
{Warning
An underhood electric fan can start
up even when the engine is not
running and can cause injury. Keep
hands, clothing, and tools away
from any underhood electric fan.
{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.
Engine Coolant
The cooling system in the vehicle is
filled with DEX-COOL engine coolant.
See Maintenance Schedule 0380 and
Recommended Fluids and Lubricants
0 391.
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 0322.
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.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
322 VEHICLE CARE
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
Service 0403.
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.
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

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
424 INDEX
Distracted Driving . . . . . . . . . . . . . . . . . . 203
Dome Lamps . . . . . . . . . . . . . . . . . . . . . . . . 130
DoorAjar Light . . . . . . . . . . . . . . . . . . . . . . . . . 107
Delayed Locking . . . . . . . . . . . . . . . . . . . 17
Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Power Locks . . . . . . . . . . . . . . . . . . . . . . . . 17
Drive Belt Routing, Engine . . . . . . . . . 398
Drive Systems All-Wheel Drive . . . . . . . . . . . . . 236, 327
Driver
Teen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184
Driver Assistance Systems . . . . . . . . . 275
Driver Information Center (DIC) . . . . . . . . . . . . . . . . . .107, 110
Driver Mode Control . . . . . . . . . . . . . . . . 241
Driver Mode Control Light . . . . . . . . . 103
Driving
Assistance Systems . . . . . . . . . . . . . . . 283
Better Fuel Economy . . . . . . . . . . . . . 203
Characteristics andTowing Tips . . . . . . . . . . . . . . . . . . . . . 297
Competitive . . . . . . . . . . . . . . . . . . . . . . . 246
Defensive . . . . . . . . . . . . . . . . . . . . . . . . . . 204
Hill and Mountain Roads . . . . . . . . 212
If the Vehicle is Stuck . . . . . . . . . . . . 214
Impaired . . . . . . . . . . . . . . . . . . . . . . . . . . . 204
Loss of Control . . . . . . . . . . . . . . . . . . . . 206 Driving (cont'd)
Off-Road Recovery . . . . . . . . . . . . . . . . 206
Track Events and
Competitive . . . . . . . . . . . . . . . . . . . . . . 207
Vehicle Load Limits . . . . . . . . . . . . . . 214
Wet Roads . . . . . . . . . . . . . . . . . . . . . . . . . 211
Winter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213
Dual Automatic Climate Control System . . . . . . . . . . . . . . . . . . . . 196
E
Electric Brake Boost . . . . . . . . . . . . . . . . 236
Electric Parking Brake . . . . . . . . . . . . . . 237
Electric Parking Brake Light . . . . . . . 100
Electrical Equipment, Add-On . . . . . 303
Electrical SystemEngine Compartment Fuse
Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332
Fuses and Circuit Breakers . . . . . . . 331
Instrument Panel Fuse Block . . . . 334
Overload . . . . . . . . . . . . . . . . . . . . . . . . . . . 330
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
Emergency OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 414
Engine
Air Cleaner/Filter . . . . . . . . . . . . . . . . . 316 Engine (cont'd)
Check Light (Malfunction
Indicator) . . . . . . . . . . . . . . . . . . . . . . . . . 97
Compartment Overview . . . . . . . . . . 309
Coolant Temperature Gauge . . . . . . . . . . . . . . . . . . . . . . . . . 94, 95
Coolant Temperature
Warning Light . . . . . . . . . . . . . . . . . . . 103
Cooling System . . . . . . . . . . . . . . . . . . . 317
Drive Belt Routing . . . . . . . . . . . . . . . . 398
Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226
Heater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222
Oil Life System . . . . . . . . . . . . . . . . . . . . 314
Oil Pressure Light . . . . . . . . . . . . . . . . . 104
Overheating . . . . . . . . . . . . . . . . . . . . . . . 322
Power Messages . . . . . . . . . . . . . . . . . . 117
Running While Parked . . . . . . . . . . . 227
Starting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220
Engine Air Filter Life System . . . . . . 315
Entry Lighting . . . . . . . . . . . . . . . . . . . . . . 131
Equipment, Towing . . . . . . . . . . . . . . . . . 302
Event Data Recorders . . . . . . . . . . . . . . 411
Exit Lighting . . . . . . . . . . . . . . . . . . . . . . . . 132
Extended Parking . . . . . . . . . . . . . . . . . . . 226
Extender, Seat Belt . . . . . . . . . . . . . . . . . . 46
Exterior Lamp Controls . . . . . . . . . . . . 126
Exterior Lamps Off Reminder . . . . . . 128
Exterior Lighting Battery Saver . . . . 133

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
426 INDEX
Headlamps (cont'd)High/Low Beam Changer . . . . . . . . . 128
Lamps On Reminder . . . . . . . . . . . . . . 106
Heated Steering Wheel . . . . . . . . . . . . . . . . . . . . . 82
Heated and Ventilated Front Seats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Heated Mirrors . . . . . . . . . . . . . . . . . . . . . . . 25
Heater Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222
Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
High-Beam On Light . . . . . . . . . . . . . . . . 105
High-Speed Operation . . . . . . . . . . . . . . 347
Hill and Mountain Roads . . . . . . . . . . 212
Hill Start Assist (HSA) . . . . . . . . . . . . . 238
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
How to Wear Seat Belts Properly . . . 42
HVAC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
I
If the System Needs Service . . . . . . . 163
Ignition Positions . . . . . . . . . . . . . . . . . . . 219
Immobilizer . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Indicator Pedestrian Ahead . . . . . . . . . . . . . . . . . 102
Vehicle Ahead . . . . . . . . . . . . . . . . . . . . . 102 Infants and Young Children,
Restraints . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Information Publication Ordering . . . . . . . . . . . . . 408
Infotainment System . . . . . . . . . . . . . . . 412
Instrument Cluster . . . . . . . . . . . . . . 88, 90
Instrument Panel Overview . . . . . . . . . . . 4
Interior Rearview Mirrors . . . . . . . . . . . 26
Introduction . . . . . . . . . . . . . . . . . . . . . . 1, 134
J
Jump Starting - North America . . . . 366
K
Keyless Entry Remote (RKE) System . . . . . . . . . . . . . . . 7
Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
L
Labeling, Tire Sidewall . . . . . . . . . . . . . 342
Lamps
Cornering . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Courtesy . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Daytime Running (DRL) . . . . . . . . . . 128
Dome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Exterior Controls . . . . . . . . . . . . . . . . . . 126
Exterior Lamps Off Reminder . . . . 128
Exterior Lighting BatterySaver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 Lamps (cont'd)
Front Turn Signal . . . . . . . . . . . . . . . . . 330
Malfunction Indicator (Check
Engine) . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
On Reminder . . . . . . . . . . . . . . . . . . . . . . 106
Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
Lane Change Alert (LCA) . . . . . . . . . . . 289
Lane Keep Assist (LKA) . . . . . . . . . . . . 291
Lane Keep Assist Light . . . . . . . . . . . . . 101
Lap-Shoulder Belt . . . . . . . . . . . . . . . . . . . . 44
LATCH System Replacing Parts after a Crash . . . . . 72
LATCH, Lower Anchors and Tethers for Children . . . . . . . . . . . . . . . 65
LED Lighting . . . . . . . . . . . . . . . . . . . . . . . . 330
Light Performance Shifting . . . . . . . . . . . . . 101
Lighting Entry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
Exit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
Illumination Control . . . . . . . . . . . . . . 130
LED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330
Lights Airbag Readiness . . . . . . . . . . . . . . . . . . 96
Antilock Brake System (ABS)Warning . . . . . . . . . . . . . . . . . . . . . . . . . 100
Automatic Vehicle Hold . . . . . . . . . . 101
Brake System Warning . . . . . . . . . . . . 99