engine overheat CADILLAC XT6 2021 User Guide

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
VEHICLE CARE 317
{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 engine cooling system in the
vehicle is filled with DEX-COOL engine
coolant mixture. This coolant needs to
be checked and changed at
appropriate levels. SeeRecommended
Fluids and Lubricants 0389 and
Maintenance Schedule 0380.
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 0320.
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
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 pouring 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.

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
318 VEHICLE CARE
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 mark 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. SeeEngine Overheating 0320.
The coolant surge tank is in the
engine compartment on the driver
side of the vehicle. See Engine
Compartment Overview 0308.
How to Add Coolant to the
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
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
(Continued)
Caution (Continued)
cause system damage. If coolant is
not visible in the surge tank,
contact your dealer.
The coolant surge tank pressure cap
can be removed when the cooling
system, including the surge tank
pressure cap and upper radiator hose,
is no longer hot.
Coolant Fill Instructions (3.6L
Engine Only)
1. Turn the pressure cap slowly counterclockwise. If a hiss is heard,
wait for that to stop. A hiss means
there is still some pressure left.
2. Keep turning the pressure cap slowly and remove it.

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
320 VEHICLE CARE
4. Put the vehicle in Service Mode.See Ignition Positions 0232.
5. Turn off the air conditioning.
6. Set the parking brake.
7. At the same time, press the accelerator and the brake for
automatic transmission vehicles for
two seconds, then release.
At the end of the cycle, check the
coolant level in the surge tank and
add coolant, if it is low. Turn off the
vehicle, allow the Engine Control
Module (ECM) to go to sleep, about
two minutes, and repeat steps 3-7.
Listen for pump activation and
movement of the control valves while
watching the level of the tank. If the
tank empties, turn the ignition off,
carefully remove the surge tank cap,
refill to the indicated mark and repeat
steps 3-6. The fill and air removal
process will run for approximately
10 minutes.
Engine Overheating
The vehicle has several indicators to
warn of the engine overheating. There is an engine coolant
temperature gauge on the instrument
cluster. See
Engine Coolant Temperature
Gauge 0113. The vehicle may also
display a message on the Driver
Information Center (DIC).
If the decision is made not to lift the
hood when this warning appears, get
service help right away. See Roadside
Service 0401.
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.

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
VEHICLE CARE 321
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 engine coolant temperature
gauge is no longer in the overheated
area or the engine coolant
temperature warning light no longer
displays, the vehicle can be driven.
Continue to drive the vehicle slowly
for about 10 minutes. Keep a safe
distance from the vehicle in front.
If the warning does not come back on,
continue to drive normally and have
the cooling system checked for proper
fill and function.
If the warning continues, pull over,
stop, and park the vehicle right away.
If there is no sign of steam, idle the
engine for three minutes while parked.
If the warning is still displayed, turn
off the engine until it cools down.Washer Fluid
What to Use
When windshield washer fluid is
needed, be sure to read the
manufacturer's instructions before
use. If operating the vehicle in an area
where the temperature may fall below
freezing, use a fluid that has sufficient
protection against freezing.
Adding Washer Fluid
The appropriate message will appear
in the Driver Information Center (DIC)
when the fluid level is low.
Open the cap with the washer symbol
on it. Add washer fluid until the tank
is full. See Engine Compartment
Overview 0308 for reservoir location.
Caution
.Do not use washer fluid that
contains any type of water
repellent coating. This can cause
the wiper blades to chatter
or skip.
.Do not use engine coolant
(antifreeze) in the windshield
washer. It can damage the
windshield washer system and
paint.
.Do not mix water with
ready-to-use washer fluid. Water
can cause the solution to freeze
and damage the washer fluid
tank and other parts of the
washer system.
.When using concentrated washer
fluid, follow the manufacturer
instructions for adding water.
.Fill the washer fluid tank only
three-quarters full when it is very
cold. This allows for fluid
expansion if freezing occurs,
which could damage the tank if
it is completely full.

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/9/21
INDEX 421
Door (cont'd)Power Locks . . . . . . . . . . . . . . . . . . . . . . . . 18
Drive Belt Routing, Engine . . . . . . . . . 396
Drive Systems All-Wheel Drive . . . . . . . . . . . . . 245, 324
Driver Teen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
Driver Assistance Systems . . . . . . . . . 263
Driver Information Center (DIC) . . . . . . . . . . . . . . . . . . . . . . . 124
Driver Mode Control . . . . . . . . . . . . . . . . 250
Driver Mode Control Light . . . . . . . . . 121
Driving Assistance Systems . . . . . . . . . . . . . . . 272
Better Fuel Economy . . . . . . . . . . . . . 218
Characteristics andTowing Tips . . . . . . . . . . . . . . . . . . . . . 290
Defensive . . . . . . . . . . . . . . . . . . . . . . . . . . 219
Hill and Mountain Roads . . . . . . . . 226
If the Vehicle is Stuck . . . . . . . . . . . . 228
Impaired . . . . . . . . . . . . . . . . . . . . . . . . . . . 219
Loss of Control . . . . . . . . . . . . . . . . . . . . 221
Off-Road . . . . . . . . . . . . . . . . . . . . . . . . . . . 222
Off-Road Recovery . . . . . . . . . . . . . . . . 221
Vehicle Load Limits . . . . . . . . . . . . . . 228
Wet Roads . . . . . . . . . . . . . . . . . . . . . . . . . 225
Winter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226 Dual Automatic Climate
Control System . . . . . . . . . . . . . . . . . . . . 208
E
Electric Brake Boost . . . . . . . . . . . . . . . . 246
Electric Parking Brake . . . . . . . . . . . . . . 246
Electric Parking Brake Light . . . . . . . 117
Electrical Equipment, Add-On . . . . . 301
Electrical System
Engine Compartment FuseBlock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329
Fuses and Circuit Breakers . . . . . . . 328
Instrument Panel Fuse Block . . . . 332
Overload . . . . . . . . . . . . . . . . . . . . . . . . . . . 327
Rear Compartment Fuse
Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335
Emergency
OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 411
Engine Air Cleaner/Filter . . . . . . . . . . . . . . . . . 315
Check Light (MalfunctionIndicator) . . . . . . . . . . . . . . . . . . . . . . . . 115
Compartment Overview . . . . . . . . . . 308
Coolant Temperature Gauge . . . . . 113
Coolant Temperature Warning Light . . . . . . . . . . . . . . . . . . . 121
Cooling System . . . . . . . . . . . . . . . . . . . 316
Drive Belt Routing . . . . . . . . . . . . . . . . 396 Engine (cont'd)
Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239
Heater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235
Oil Life System . . . . . . . . . . . . . . . . . . . . 313
Oil Pressure Light . . . . . . . . . . . . . . . . . 122
Overheating . . . . . . . . . . . . . . . . . . . . . . . 320
Power Messages . . . . . . . . . . . . . . . . . . 130
Running While Parked . . . . . . . . . . . 239
Starting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233
Engine Air Filter Life System . . . . . . 314
Entry Lighting . . . . . . . . . . . . . . . . . . . . . . 144
Equipment, Towing . . . . . . . . . . . . . . . . . 297
Event Data Recorders . . . . . . . . . . . . . . 408
Exit Lighting . . . . . . . . . . . . . . . . . . . . . . . . 145
Extended Parking . . . . . . . . . . . . . . . . . . . 239
Extender, Seat Belt . . . . . . . . . . . . . . . . . . 59
Exterior Lamp Controls . . . . . . . . . . . . 139
Exterior Lamps Off Reminder . . . . . . 141
Exterior Lighting Battery Saver . . . . 145
F
Filter, Engine Air Cleaner . . . . . . . . . . . . . . . . 315
Flash-to-Pass . . . . . . . . . . . . . . . . . . . . . . . . 141
Flashers, Hazard Warning . . . . . . . . . . 142
Flat Tire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 357 Changing . . . . . . . . . . . . . . . . . . . . . . . . . . 358
Floor Mats . . . . . . . . . . . . . . . . . . . . . . . . . . . 377

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/9/21
INDEX 425
Online Owner Center . . . . . . . . . . . . . . . 400
OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 409
OnStar Additional Information . . . . 411
OnStar Emergency . . . . . . . . . . . . . . . . . . 411
OnStar Overview . . . . . . . . . . . . . . . . . . . . 410
OnStar Security . . . . . . . . . . . . . . . . . . . . . 411
OnStar System . . . . . . . . . . . . . . . . .161, 172
OutletsPower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
Overheating, Engine . . . . . . . . . . . . . . . . 320
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 Instrument Panel . . . . . . . . . . . . . . . . . . . . 4
P
ParkShifting Into . . . . . . . . . . . . . . . . . . . . . . 237
Shifting Out of . . . . . . . . . . . . . . . . . . . . 238
Park Assist . . . . . . . . . . . . . . . . . . . . . . . . . . 264
Parking Brake and P (Park)Mechanism Check . . . . . . . . . . . . . . . 324
Extended . . . . . . . . . . . . . . . . . . . . . . . . . . 239
Over Things That Burn . . . . . . . . . . . 238
Parking or Backing Assistance Systems . . . . . . . . . . . . . . . 264
Passenger Airbag Status
Indicator . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 Passenger Compartment Air
Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216
Passenger Sensing System . . . . . . . . . . 66
Pedestrian Ahead Indicator . . . . . . . . 120
Perchlorate Materials Requirements, California . . . . . . . . . 305
Performance Shifting Light . . . . . . . . 119
Personalization
Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Phone Apple CarPlay and
Android Auto . . . . . . . . . . . . . . . . . . . . 186
Bluetooth . . . . . . . . . . . . . . . . . . . . 181, 182
Port USB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
Positioning
Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
Power Door Locks . . . . . . . . . . . . . . . . . . . . . . . . . 18
Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Outlets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
Protection, Battery . . . . . . . . . . . . . . . . 145
Retained Accessory (RAP) . . . . . . . . 237
Seat Adjustment . . . . . . . . . . . . . . . . . . . 41
Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Pregnancy, Using Seat Belts . . . . . . . . . 59
Privacy Vehicle Data Recording . . . . . . . . . . 408 Problems with Route Guidance . . . . 174
Program
Courtesy Transportation . . . . . . . . . 403
Prohibited Fuels . . . . . . . . . . . . . . . . . . . . 287
Proposition 65 Warning,
California . . . . . . . . . . . . . . .304, 323, 364, Back Cover
Publication Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . 406
R
RadioHD Radio Technology . . . . . . . . . . . . 155
Radio Data System (RDS) . . . . . . . . . . 155
Radio Frequency Statement . . . . . . . . 406
Radio Reception . . . . . . . . . . . . . . . . . . . . 156
Radios AM-FM Radio . . . . . . . . . . . . . . . . . . . . . 153
Satellite . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
Reading Lamps . . . . . . . . . . . . . . . . . . . . . 144
Rear Camera Mirror . . . . . . . . . . . . . . . . . 32
Rear Climate Control System . . . . . . 213
Rear Pedestrian Alert . . . . . . . . . . . . . . . 271
Rear Seats . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Heated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Rear Storage . . . . . . . . . . . . . . . . . . . . . . . . . 93
Rear Vision Camera (RVC) . . . . . . . . . 264