2015 CADILLAC CTS SEDAN cooling

Black plate (19,1)Cadillac CTS Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707478) - 2015 - crc - 10/1/14
Vehicle Care 10-19
Never dispose of engine coolant by
putting it in the trash, pouring it on
the ground, or 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.
It is normal to see coolant moving in
the upper coolant hose return line
when the engine is running. It is
also normal to see bubbles entering
the surge tank through the
small hose.
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 is not at or above the COLD
FILL line, add a 50/50 mixture of
clean drinkable water and
DEX-COOL coolant.
Be sure the cooling system is cool
before this is done.
If no coolant is visible in the coolant
surge tank, add coolant as follows:
How to Add Coolant to the
Coolant Surge Tank
{Caution
This vehicle has a specific
coolant fill procedure. Failure to
follow this procedure could cause
the engine to overheat and be
severely damaged.
If no problem is found, check to see
if coolant is visible in the coolant
surge tank. If coolant is visible but
the coolant level is not at the bottom
of the fill neck, add a 50/50 mixture
of 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
(Continued)

Black plate (20,1)Cadillac CTS Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707478) - 2015 - crc - 10/1/14
10-20 Vehicle Care
Warning (Continued)
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 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
and it will burn if the engine parts
are hot enough. Do not spill
coolant on a hot engine.
1. Remove the coolant surge tankpressure cap from the top
chamber 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. 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. Open the
surge tank service port cap to
the lower chamber. The service
port is behind the top chamber.
3. Fill the surge tank top chamber with the proper DEX-COOL
coolant mixture to the bottom of
the fill neck. The top chamber
needs to be completely full. Fill
the surge tank bottom chamber
through the service port to
approximately half.

Black plate (21,1)Cadillac CTS Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707478) - 2015 - crc - 10/1/14
Vehicle Care 10-21
4. With the coolant surge tankpressure cap off and the surge
tank service port cap open, start
the engine and let it run until you
can feel the upper radiator hose
getting hot. Watch out for the
engine cooling fan(s).
By this time, the coolant level
inside the coolant surge tank top
chamber may be lower. If the
level is lower, add more of the
proper DEX-COOL coolant
mixture to the surge tank top
chamber until the level reaches
the bottom of the fill neck.
5. Replace the surge tank pressure cap tightly and close the surge
tank service port cap.
{Caution
If the pressure cap is not tightly
installed, coolant loss and
possible engine damage may
occur. Be sure the cap is properly
and tightly secured. Check the level in the surge tank
top and bottom chambers when the
cooling system has cooled down.
If the coolant is not at the proper
levels, repeat Steps 1–3 and
reinstall the pressure cap and close
the service port. If the coolant still is
not at the proper levels when the
system cools down again, see your
dealer.
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 on page 13-5.
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
Running the engine without
coolant may cause damage or a
fire. Vehicle damage would not be
covered by the vehicle warranty.
If Steam Is Coming from the
Engine Compartment
{Warning
Steam from an overheated engine
can burn you badly, even if you
just open the hood. Stay away
from the engine if you see or hear
steam coming from it. Just turn it
off and get everyone away from
the vehicle until it cools down.
Wait until there is no sign of
steam or coolant before you open
the hood.
(Continued)

Black plate (22,1)Cadillac CTS Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707478) - 2015 - crc - 10/1/14
10-22 Vehicle Care
Warning (Continued)
If you keep driving when the
engine is overheated, the liquids
in it can catch fire. You or others
could be badly burned. Stop the
engine if it overheats, and get out
of the vehicle until the engine
is 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
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 on
page 10-5 for reservoir location.

Black plate (35,1)Cadillac CTS Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707478) - 2015 - crc - 10/1/14
Vehicle Care 10-35
Number Usage41 Fuel Heater
*42 AIR Solenoid Relay
43 Washer
44 Not Used
45 Front Washer Relay
46 Not Used
47 Instrument Panel Body Ignition
48 Fuel System Control Module
Ignition
49 Heated Steering Wheel
*50 Steering Column Lock
*51 Coolant Pump
*52 Coolant Pump Relay
53 Air Conditioning Compressor Clutch Number Usage
*54 AIR Solenoid55 Transmission Control Module/
Spare
*56 Headlamp Low Relay
57 Headlamp High Relay
58 Starter
59 Starter Relay
60 Run/Crank Relay
*61 Vacuum Pump Relay
62 Air Conditioning Control Relay
*63 Adaptive Headlamp Leveling
*64 Left High Intensity Discharge
Headlamp Number Usage
*65 Right High Intensity Discharge
Headlamp
66 Headlamp High Left/Right
67 Horn
68 Horn Relay
69 Cooling Fan
70 Aero Shutter
71 Transmission Control Module
Ignition
72 Engine Control Module Ignition
*73 Brake Vacuum Pump
74 Not Used
* Optional

Black plate (63,1)Cadillac CTS Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707478) - 2015 - crc - 10/1/14
Vehicle Care 10-63
If the wheel leaks air, replace it.
Some aluminum wheels can be
repaired. See your dealer if any of
these conditions exist.
Your dealer will know the kind of
wheel that is needed.
Each new wheel should have the
same load-carrying capacity,
diameter, width, offset, and be
mounted the same way as the one it
replaces.
Replace wheels, wheel bolts, wheel
nuts, or Tire Pressure Monitor
System (TPMS) sensors with new
GM original equipment parts.
{Warning
Using the wrong replacement
wheels, wheel bolts, or wheel
nuts can be dangerous. It could
affect the braking and handling of
the vehicle. Tires can lose air,
and cause loss of control, causing(Continued)
Warning (Continued)
a crash. Always use the correct
wheel, wheel bolts, and wheel
nuts for replacement.
{Caution
The wrong wheel can also cause
problems with bearing life, brake
cooling, speedometer or
odometer calibration, headlamp
aim, bumper height, vehicle
ground clearance, and tire or tire
chain clearance to the body and
chassis.
Used Replacement Wheels
{Warning
Replacing a wheel with a used
one is dangerous. How it has
been used or how far it has been
driven may be unknown. It could
fail suddenly and cause a crash.
When replacing wheels, use a
new GM original equipment
wheel.
Tire Chains
{Warning
If the vehicle has P245/40R18,
245/40R18, 275/35R18, or 255/
35R19 size tires, do not use tire
chains. There is not enough
clearance. Tire chains used on a
vehicle without the proper amount
of clearance can cause damage
to the brakes, suspension,
(Continued)

Black plate (6,1)Cadillac CTS Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707478) - 2015 - crc - 10/1/14
11-6 Service and Maintenance
Maintenance Schedule
Additional Required
Services - Normal12 000 km/7,500 mi
24 000 km/15,000 mi
36 000 km/22,500 mi
48 000 km/30,000 mi
60 000 km/37,500 mi
72 000 km/45,000 mi
84 000 km/52,500 mi
96 000 km/60,000 mi
108 000 km/67,500 mi
120 000 km/75,000 mi
132 000 km/82,500 mi
144 000 km/90,000 mi
156 000 km/97,500 mi
168 000 km/105,000 mi 180 000 km/112,500 mi
192 000 km/120,000 mi
204 000 km/127,500 mi
216 000 km/135,000 mi
228 000 km/142,500 mi
240 000 km/150,000 mi
Rotate tires, if recommended for the vehicle, and
perform Required Services. Check engine oil level
and oil life percentage. Change engine oil and
filter, if needed. (1)@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
Replace passenger compartment air filter. (2)@ @@@@@
Inspect evaporative control system. (3)@ @@
Replace engine air cleaner filter. (4)@@@
Replace spark plugs. Inspect spark plug wires.
(2.0L LTG and 3.6L LF3 Turbo Engines)@ @
Replace spark plugs. Inspect spark plug wires.
(3.6L LFX Engine Only)@
Change rear axle fluid, if equipped with electronic
limited slip differential. (3.6L V6 Turbo LF3
Engine only)@@@
Drain and fill engine cooling system. (5)@
Visually inspect accessory drive belts. (6)@
Replace brake fluid. (7)@@@

Black plate (7,1)Cadillac CTS Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707478) - 2015 - crc - 10/1/14
Service and Maintenance 11-7
Footnotes—Maintenance
Schedule Additional Required
Services - Normal
(1) Vehicles with different size front
and rear tires do not have tire
rotation. See Tire Rotation on
page 10-56.
(2) Or every two years, whichever
comes first. More frequent
replacement may be needed if the
vehicle is driven in areas with heavy
traffic, areas with poor air quality,
or areas with high dust levels.
Replacement may also be needed if
there is a reduction in air flow,
excessive window fogging, or odors.
(3) Check all fuel and vapor lines
and hoses for proper hook-up,
routing, and condition.
(4) Or every four years, whichever
comes first.
(5) Or every five years, whichever
comes first. See Cooling System on
page 10-16. (6)
Or every 10 years, whichever
comes first. Inspect for fraying,
excessive cracking, or damage;
replace, if needed.
(7) Or every three years, whichever
comes first.