2017 CADILLAC CT6 heater

Cadillac CT6 Owner Manual (GMNA-Localizing-MidEast-10293390) - 2017 -
CRC - 6/21/16
256 VEHICLE CARE
{Warning
Heater and radiator hoses, and
other engine parts, can be very hot.
Do not touch them. If you do, you
can be burned.
Do not run the engine if there is a
leak. If you run the engine, it could
lose all coolant. That could cause
an engine fire, and you could be
burned. Get any leak fixed before
you drive the vehicle.
Caution
Using coolant other than
DEX-COOL®can cause premature
engine, heater core, or radiator
corrosion. In addition, the engine
coolant could require changing
sooner. Any repairs would not be
covered by the vehicle warranty.
Always use DEX-COOL (silicate-free)
coolant in the vehicle.
Engine Coolant
The cooling system in the vehicle is
filled with DEX-COOL®engine coolant.
This coolant needs to be checked and
replaced at appropriate intervals. See
Maintenance Schedule 0311.
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 0259.
What to Use
{Warning
Adding only plain water or some
other liquid to the cooling system
can be dangerous. Plain water and
other liquids, can boil before the
proper coolant mixture will. The
coolant warning system is set for
the proper coolant mixture. With
plain water or the wrong mixture,
the engine could get too hot but
you would not get the overheat
warning. The engine could catch
(Continued)
Warning (Continued)
fire and you or others could be
burned. Use a 50/50 mixture of
clean, drinkable water and
DEX-COOL coolant.
Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
coolant. If using this mixture, nothing
else needs to be added. 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 CT6 Owner Manual (GMNA-Localizing-MidEast-10293390) - 2017 -
CRC - 6/21/16
258 VEHICLE CARE
clean, drinkable water and DEX-COOL
coolant at the coolant surge tank, but
be sure the cooling system, including
the coolant surge tank pressure cap, is
cool before you do it.
{Warning
Steam and scalding liquids from a
hot cooling system can blow out
and burn you badly. Never turn the
cap when the cooling system,
including the surge tank pressure
cap, is hot. Wait for the cooling
system and surge tank pressure cap
to cool.
{Warning
Adding only plain water or some
other liquid to the cooling system
can be dangerous. Plain water and
other liquids, can boil before the
proper coolant mixture will. The
coolant warning system is set for
the proper coolant mixture. With(Continued)
Warning (Continued)
plain water or the wrong mixture,
the engine could get too hot but
you would not get the overheat
warning. The engine could catch
fire and you or others could be
burned. Use a 50/50 mixture of
clean, drinkable water and
DEX-COOL coolant.
Caution
In cold weather, water can freeze
and crack the engine, radiator,
heater core, and other parts. Use
the recommended coolant and the
proper coolant mixture.
{Warning
You can be burned if you spill
coolant on hot engine parts.
Coolant contains ethylene glycol(Continued)
Warning (Continued)
and it will burn if the engine parts
are hot enough. Do not spill coolant
on a hot engine.
1. Remove the coolant surge tank pressure cap when the cooling
system, including the coolant
surge tank pressure cap and
upper radiator hose, is no
longer hot.
Turn the pressure cap slowly
counterclockwise about
one-quarter of a turn. If you hear
a hiss, wait for that to stop. This
will allow any pressure still left
to be vented out the
discharge hose.
2. Keep turning the pressure cap slowly and remove it.
3. Fill the coolant surge tank with the proper mixture to the
indicated level mark.
4. With the coolant surge tank pressure cap off, start the engine
and let it run until you can feel

Cadillac CT6 Owner Manual (GMNA-Localizing-MidEast-10293390) - 2017 -
CRC - 6/21/16
260 VEHICLE CARE
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 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
Open the cap with the washer symbol
on it. Add washer fluid until the tank
is full. See
Engine Compartment
Overview 0247 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
(Continued)

Cadillac CT6 Owner Manual (GMNA-Localizing-MidEast-10293390) - 2017 -
CRC - 6/21/16
VEHICLE CARE 271
Number Usage21 A/C clutch
22 –
23 Coolant heater control module
24 Coolant pump
25 Coolant pump relay
26 Hi fuel
27 Steering column lock
28 Rear heated seats
29 Front heated seats
30 –
31 LED LGT battery
32 A/C control module
33 AIR solenoid
34 –
35 Engine control module
36 Engine control module 2
37 Coolant pump/ Ignition coils –odd Number Usage
38 Ignition coils –even/
Non walk 2
39 Non walk
40 Instrument cluster
41 –
42 Fuel pump power module
43 Instrument panel body/Ignition
44 Aeroshutter
45 Washer
46 Front sensor
47 Left cornering LED
48 AIR solenoid relay
49 Air pump relay
50 Engine control module relay
51 Wiper speed relay
52 Wiper control relay
53 Headlamp control relay
54 – Number Usage
55 –
56 Air pump
57 –
58 Instrument panel electronic center
59 –
60 ABS pump
61 Front wiper
62 Headlamp leveling
63 Electric brake booster module
64 –
65 –
66 Transfer case control module
67 Electric brake booster
68 Rear seat entertainment
display
69 RESS coolant pump
70 –
71 ABS valve