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Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
16412876) - 2023 - CRC - 3/25/22
340 Vehicle Care
Checking Coolant
The vehicle must be on a level
surface when checking the
coolant level.
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 surethe cooling system is cool
before this is done. See
Engine Overheating
0342.
The coolant surge tank is in
the engine compartment on
the driver side of the vehicle.
See Engine Compartment
Overview 0331.
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
(Continued)
Warning (Continued)
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 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.
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Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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Vehicle Care 341
1. Turn the pressure capslowly 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.
3. If topping off the level inthe coolant surge tank, add
the proper mixture until
the level reaches the mark
on the front of the tank
and replace the cap.
Operate the vehicle.
Repeat steps 1–3, as
necessary.
If filling the system (such
as after servicing), follow
the Automatic Coolant
Service Fill Instructions.
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.
Automatic Coolant
Service Fill Instructions
This feature assists in filling
and removing air from the
cooling system after service of
components or when coolant
is added after being too low. To activate the fill and air
removal process:
1. With a cold system, add coolant to the indicated
mark on the surge tank.
2. Replace the cap on the surge tank.
3. Connect the vehicle to a battery charger.
4. Turn the ignition to Service Mode. See Ignition
Positions 0247.
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 Electronic Control Module
(ECM) to go to sleep, about
2 minutes, and repeat
Steps 3-7.
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Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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342 Vehicle Care
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 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
0123. 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
Assistance Program 0439. 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
(Continued)
Warning (Continued)
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.
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Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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Vehicle Care 343
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
0331 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
(Continued)