2021 CADILLAC XT6 overheating

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 337
Wheels and Tires
Tires
Every new GM vehicle has
high-quality tires made by a
leading tire manufacturer. See the
warranty manual for information
regarding the tire warranty and
where to get service. For
additional information refer to the
tire manufacturer.
{Warning
.Poorly maintained and
improperly used tires are
dangerous.
.Overloading the tires can
cause overheating as a result
of too much flexing. There
could be a blowout and a
serious crash. SeeVehicle
Load Limits 0228.
.Underinflated tires pose the
same danger as overloaded
tires. The resulting crash
(Continued)
Warning (Continued)
could cause serious injury.
Check all tires frequently to
maintain the recommended
pressure. Tire pressure should
be checked when the tires
are cold.
.Overinflated tires are more
likely to be cut, punctured,
or broken by a sudden impact
— such as when hitting a
pothole. Keep tires at the
recommended pressure.
.Worn or old tires can cause a
crash. If the tread is badly
worn, replace them.
.Replace any tires that have
been damaged by impacts
with potholes, curbs, etc.
.Improperly repaired tires can
cause a crash. Only your
dealer or an authorized tire
(Continued)
Warning (Continued)
service center should repair,
replace, dismount, and mount
the tires.
.Do not spin the tires in
excess of 56 km/h (35 mph)
on slippery surfaces such as
snow, mud, ice, etc. Excessive
spinning may cause the tires
to explode.
See Tire Pressure for High-Speed
Operation 0345 for inflation
pressure adjustment for
high-speed driving.
All-Season Tires
This vehicle may come with all-season
tires. These tires are designed to
provide good overall performance on
most road surfaces and weather
conditions. Original equipment tires
designed to GM's specific tire
performance criteria have a TPC
specification code molded onto the
sidewall. Original equipment

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
344 VEHICLE CARE
{Warning
Neither tire underinflation nor
overinflation is good.
Underinflated tires, or tires that
do not have enough air, can
result in:
.Tire overloading and
overheating, which could lead
to a blowout.
.Premature or irregular wear.
.Poor handling.
.Reduced fuel economy.
Overinflated tires, or tires that
have too much air, can result in:
.Unusual wear.
.Poor handling.
.Rough ride.
.Needless damage from road
hazards.
The Tire and Loading Information
label on the vehicle indicates the
original equipment tires and the
correct cold tire inflation pressures. The recommended
pressure is the minimum air
pressure needed to support the
vehicle's maximum load carrying
capacity. See
Vehicle Load Limits
0 228.
How the vehicle is loaded affects
vehicle handling and ride comfort.
Never load the vehicle with more
weight than it was designed to
carry.
When to Check
Check the pressure of the tires
once a month or more. Do not
forget the compact spare, if the
vehicle has one. The compact
spare cold tire pressure should be
at 420 kPa (60 psi). See Compact
Spare Tire 0364.
How to Check
Use a good quality pocket-type
gauge to check tire pressure.
Proper tire inflation cannot be
determined by looking at the tire.
Check the tire inflation pressure when the tires are cold, meaning
the vehicle has not been driven for
at least three hours or no more
than 1.6 km (1 mi).
Remove the valve cap from the
tire valve stem. Press the tire
gauge firmly onto the valve to get
a pressure measurement. If the
cold tire inflation pressure
matches the recommended
pressure on the Tire and Loading
Information label, no further
adjustment is necessary. If the
inflation pressure is low, add air
until the recommended pressure is
reached. If the inflation pressure
is high, press on the metal stem in
the center of the tire valve to
release air.
Recheck the tire pressure with the
tire gauge.
Put the valve caps back on the
valve stems to keep out dirt and
moisture. Use only valve caps
designed for the vehicle by GM.

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