2020 CADILLAC CT4 Owner's Manual

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
264 VEHICLE CARE
FusesUsage
2 HVAC blower
3 –
4 –
5 Theft deterrent/ Universal garage door
opener
6 –
7 Air quality ionizer
8 Heated steering wheel
9 –
10 Electronic steering column lock 1
11 –
12 –
13 –
14 –
15 –
16 –
17 –
18 Display/ Infotainment/USB Fuses
Usage
19 Airbag/Automatic occupant sensing/
Data link connection/
Wireless charging
module
20 Power steering column module/
Electronic steering
column lock 2
21 –
22 –
23 –
24 –
25 USB
26 –
27 –
28 –
29 –
30 –
31 Headlamp level
32 – Fuses
Usage
33 Body ignition/IP ignition
34 Exhaust valve
35 Transmission control module ignition/
Engine control
module ignition/Shift
ignition/Brake
ignition
36 Shift module
37 Body control module 1/Electronic
park brake switch
38 Center stack module
39 Steering wheel controls
40 Body control module 2
41 Body control module 3
42 Body control module 4

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
VEHICLE CARE 265
Circuit
Breakers Usage
CB1 Auxiliary power outlet 1
CB2 Auxiliary power outlet 2
Relays Usage 1 Run after park/ Accessory
2 Run crank
3 –
4 –
5 –Rear Compartment Fuse
Block
The rear compartment fuse block is
behind a cover on the driver side of
the rear compartment.
The vehicle may not be equipped with
all of the fuses, relays, and features
shown.
Fuses Usage
1 Remote function actuator

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
266 VEHICLE CARE
FusesUsage
2 Engine control module
3 Driver heated seat
4 Fuel tank zone module
5 –
6 –
7 –
8 –
9 –
10 Motor seat belt passenger
11 Canister vent solenoid
12 Sunroof
13 –
14 –
15 Passenger heated seat
16 –
17 Electronic suspension control Fuses
Usage
18 –
19 Motor seat belt driver
20 Rear defog
21 DC to DC transformer 2
22 Driver power window door lock switch
23 External object calculating module/
Front camera module
24 Passenger window door lock switch
25 –
26 Trailer
27 Rear drive control module
28 –
29 –
30 –
31 DC to DC transformer 1 Fuses
Usage
32 Transfer case electronic control
33 Central gateway module/Side blind
zone alert
34 Video processing module
35 Hands free closure release
36 Exterior lighting module 2
37 Passenger memory seat module
38 Trailer 2
39 Right front/Right rear window
40 –
41 –
42 Amplifier
43 Park assist module
44 Driver memory seat module
45 OnStar

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
VEHICLE CARE 267
FusesUsage
46 –
47 –
48 –
49 Trailer
50 Driver seat
51 Left front/Left rear window
52 Passenger seat
Relays Usage
53 –
54 –
55 RunWheels 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. See
Vehicle Load Limits 0154.
(Continued)
Warning (Continued)
.Underinflated tires pose
the same danger as
overloaded tires. The
resulting crash 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.
(Continued)

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
268 VEHICLE CARE
Warning (Continued)
.Replace any tires that have
been damaged by impacts
with potholes, curbs, etc.
.Improperly repaired tires
can cause a crash. Only
the dealer or an authorized
tire 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 0276 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
all-season tires can be identified by
the last two characters of this TPC
code, which will be “MS.”
Consider installing winter tires on the
vehicle if frequent driving on snow or
ice-covered roads is expected.
All-season tires provide adequate
performance for most winter driving
conditions, but they may not offer the
same level of traction or performance
as winter tires on snow or ice-covered
roads. See Winter Tires 0268.
Winter Tires
This vehicle was not originally
equipped with winter tires. Winter
tires are designed for increased
traction on snow and ice-covered roads. Consider installing winter tires
on the vehicle if frequent driving on
ice or snow covered roads is expected.
See your dealer for details regarding
winter tire availability and proper tire
selection. Also, see
Buying New Tires
0 282.
With winter tires, there may be
decreased dry road traction, increased
road noise, and shorter tread life.
After changing to winter tires, be alert
for changes in vehicle handling and
braking.
If using winter tires:
. Use tires of the same brand and
tread type on all four wheel
positions.
. Use only radial ply tires of the
same size, load range, and speed
rating as the original equipment
tires.
Winter tires with the same speed
rating as the original equipment tires
may not be available for H, V, W, Y,
and ZR speed rated tires. If winter
tires with a lower speed rating are
chosen, never exceed the tire's
maximum speed capability.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
VEHICLE CARE 269
Run-Flat Tires
This vehicle, when new, may have had
run-flat tires. There is no spare tire,
no tire changing equipment, and no
place to store a tire in the vehicle.
The vehicle also has a Tire Pressure
Monitor System (TPMS) that indicates
a loss of tire pressure in any of the
tires.
{Warning
If the low tire warning light displays
on the instrument cluster, the
handling capabilities will be
reduced during severe maneuvers.
Driving too fast could cause loss of
control and you or others could be
injured. Do not drive over 80 km/h
(50 mph) when the low tire warning
light is displayed. Drive cautiously
and check the tire pressures as
soon as possible.
Run-flat tires can be driven up to
80 km (50 mi) at speeds less than
80km/h (50 mph) after a loss of
inflation pressure has occurred. There is no need to stop on the side of the
road to change the tire. The possible
driving range after a pressure loss will
vary based on the vehicle load and
driving conditions. As soon as
possible, contact the nearest
authorized GM or run-flat servicing
facility for inspection and repair or
replacement.
When driving on a deflated run-flat
tire, avoid potholes and other road
hazards that could damage the tire
and/or wheel beyond repair. When a
tire has been damaged, or driven any
distance while deflated, check with an
authorized run-flat tire service center
to determine whether the tire can be
repaired or should be replaced. To
maintain the run-flat feature, all
replacement tires must be run-flat
tires.
To locate the nearest GM or run-flat
servicing facility, call Customer
Assistance.
Self-Sealing Tires
This vehicle may have self-sealing
tires. These tires have a material
inside that can seal punctures up to6 mm (0.25 in) in the tread area. The
tire may lose air pressure if the
sidewall is damaged or the tread
puncture is too large. If the Tire
Pressure Monitor System indicates the
tire pressure is low, inspect the tire for
damage and inflate it to the
recommended pressure. If the tire is
unable to maintain the recommended
pressure, contact the nearest
authorized GM servicing facility
immediately for inspection and repair
or replacement. To locate the nearest
GM servicing facility, call GM
Customer Assistance.
Caution
Do not drive on a deflated
self-sealing tire as this could
damage the tire. Make sure the tire
is inflated to the recommended
pressure or have it immediately
repaired or replaced.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
270 VEHICLE CARE
When tire replacement is needed
replace with a self-sealing tire,
because the vehicle does not come
with a spare tire or tire changing
equipment.
Low-Profile Tires
If the vehicle has 225/45R17 91V,
235/40R18 91V, 235/40R18 XL
95Y, or 235/35R19 XL 91V size
tires, they are classified as
low-profile tires.Caution
Low-profile tires are more
susceptible to damage from road
hazards or curb impact than
standard profile tires. Tire and/or
wheel assembly damage can occur
when coming into contact with
road hazards like potholes, or sharp
edged objects, or when sliding into
a curb. The warranty does not cover
this type of damage. Keep tires set
to the correct inflation pressure and (Continued)
Caution (Continued)
when possible, avoid contact with
curbs, potholes, and other road
hazards.
Summer Tires
High Performance Summer Tires
This vehicle may come with 225/
45R17 SL 91V or 235/40R18 XL 95Y
high performance summer tires. These
tires have a special tread and
compound that are optimized for
maximum dry and wet road
performance. This special tread and
compound will have decreased
performance in cold climates, and on
ice and snow. It is recommended that
winter tires be installed on the vehicle
if frequent driving at temperatures
below approximately 5 °C (40 °F) or on
ice or snow covered roads is expected.
SeeWinter Tires 0268.
Caution
High performance summer tires
have rubber compounds that lose
flexibility and may develop surface
cracks in the tread area at
temperatures below −7 °C (20 °F).
Always store high performance
summer tires indoors and at
temperatures above −7 °C (20 °F)
when not in use. If the tires have
been subjected to −7 °C (20 °F) or
less, let them warm up in a heated
space to at least 5 °C (40 °F) for
24 hours or more before being
installed or driving a vehicle on
which they are installed. Do not
apply heat or blow heated air
directly on the tires. Always inspect
tires before use. See Tire Inspection
0 280.
Tire Sidewall Labeling
Useful information about a tire is
molded into its sidewall. The
example shows a typical passenger
tire sidewall.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
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Passenger (P-Metric) Tire Example
(1) Tire Size:The tire size is a
combination of letters and
numbers used to define a
particular tire's width, height,
aspect ratio, construction type,
and service description. See the
“Tire Size ”illustration later in this
section.
(2) TPC Spec (Tire Performance
Criteria Specification)
:Original
equipment tires designed to GM's
specific tire performance criteria
have a TPC specification code molded onto the sidewall. GM's
TPC specifications meet or exceed
all federal safety guidelines.
(3) DOT (Department of
Transportation)
:The
Department of Transportation
(DOT) code indicates that the tire
is in compliance with the U.S.
Department of Transportation
Motor Vehicle Safety Standards.
DOT Tire Date of Manufacture
:
The last four digits of the TIN
indicate the tire manufactured
date. The first two digits represent
the week (01-52) and the last two
digits, the year. For example, the
third week of the year 2010 would
have a four-digit DOT date
of 0310.
(4) Tire Identification Number
(TIN)
:The letters and numbers
following the DOT code are the
Tire Identification Number (TIN).
The TIN shows the manufacturer
and plant code, tire size, and date
the tire was manufactured. The TIN is molded onto both sides of
the tire, although only one side
may have the date of
manufacture.
(5) Tire Ply Material
:The type
of cord and number of plies in the
sidewall and under the tread.
(6) Uniform Tire Quality
Grading (UTQG)
:Tire
manufacturers are required to
grade tires based on three
performance factors: treadwear,
traction, and temperature
resistance. For more information
see Uniform Tire Quality Grading
0 284.
(7) Maximum Cold Inf lation
Load Limit
:Maximum load that
can be carried and the maximum
pressure needed to support
that load.