2020 CADILLAC CT4 light

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
220 DRIVING AND OPERATING
{Warning
Using LKA while towing a trailer or
on slippery roads could cause loss
of control of the vehicle and a
crash. Turn the system off.
How the System Works
LKA uses a camera sensor installed on
the windshield ahead of the rearview
mirror to detect lane markings. It may
provide brief steering assist if it
detects an unintended lane departure.
It may further provide an audible alert
or the driver seat may pulse indicating
that a lane marking has been crossed.
To turn LKA on and off, press
Aon
the center stack. If equipped, the
indicator light on the button comes
on when LKA is on and turns off
when LKA is disabled.
When on,
Ais white, if equipped,
indicating that the system is not ready
to assist.
Ais green if LKA is ready
to assist. LKA may assist by gently
turning the steering wheel if the
vehicle approaches a detected lane marking.
Ais amber when
assisting. It may also provide a Lane
Departure Warning (LDW) alert by
flashing
Aamber if the vehicle
crosses a detected lane marking.
Additionally, there may be three
beeps, or the driver seat may pulse
three times, on the right or left,
depending on the lane departure
direction.
Take Steering
The LKA system does not
continuously steer the vehicle. If LKA
does not detect active driver steering,
an alert and chime may be provided.
Steer the vehicle to dismiss. LKA may
become temporarily unavailable after
repeated take steering alerts.
When the System Does Not
Seem to Work Properly
The system performance may be
affected by:
. Close vehicles ahead.
. Sudden lighting changes, such as
when driving through tunnels.
. Banked roads. .
Roads with poor lane markings,
such as two-lane roads.
If the LKA system is not functioning
properly when lane markings are
clearly visible, cleaning the windshield
may help.
A camera blocked message may
display if the camera is blocked. Some
driver assistance systems may have
reduced performance or not work at
all. An LKA or LDW unavailable
message may display if the systems
are temporarily unavailable. This
message could be due to a blocked
camera. The LKA system does not
need service. Clean the outside of the
windshield behind the rearview mirror.
LKA assistance and/or LDW alerts
may occur due to tar marks, shadows,
cracks in the road, temporary or
construction lane markings, or other
road imperfections. This is normal
system operation; the vehicle does not
need service. Turn LKA off if these
conditions continue.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
DRIVING AND OPERATING 231
Cross the safety chains under the
tongue of the trailer to help prevent
the tongue from contacting the road if
it becomes separated from the hitch.
Always leave just enough slack so the
combination can turn. Never allow
safety chains to drag on the ground.
Trailer Brakes
Loaded trailers over 450 kg (1,000 lb)
must be equipped with brake systems
and with brakes for each axle. Trailer
braking equipment conforming to
Canadian Standards Association (CSA)
requirement CAN3-D313, or its
equivalent, is recommended.
State or local regulations may require
trailers to have their own braking
system if the loaded weight of the
trailer exceeds certain minimums that
can vary from state to state. Read and
follow the instructions for the trailer
brakes so they are installed, adjusted,
and maintained properly. Never
attempt to tap into your vehicle's
hydraulic brake system. If you do,
both the vehicle anti-lock brakes and
the trailer brakes may not function,
which could result in a crash.
Trailer Lamps
Always check all trailer lamps are
working at the beginning of each trip,
and periodically on longer trips.
Turn Signals When Towing a
Trailer
When properly connected, the trailer
turn signals will illuminate to indicate
the vehicle is turning, changing lanes,
or stopping. When towing a trailer,
the arrows on the instrument cluster
will illuminate even if the trailer is not
properly connected or the bulbs are
burned out.
Conversions and
Add-Ons
Add-On Electrical
Equipment
{Warning
The Data Link Connector (DLC) is
used for vehicle service and
Emission Inspection/Maintenance
testing. SeeMalfunction Indicator
Lamp (Check Engine Light) 0100.
A device connected to the DLC —
such as an aftermarket fleet or
driver-behavior tracking device —
may interfere with vehicle systems.
This could affect vehicle operation
and cause a crash. Such devices
may also access information stored
in the vehicle’s systems.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
VEHICLE CARE 233
Vehicle Care
General Information
General Information . . . . . . . . . . . . . 234
California Proposition65 Warning . . . . . . . . . . . . . . . . . . . . . 234
California Perchlorate Materials Requirements . . . . . . . . . . . . . . . . . . . 235
Accessories and Modifications . . . . . . . . . . . . . . . . . . . 235
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . . . . . . 235
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . . . . . . 238
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . 241
Engine Oil Life System . . . . . . . . . . . 243
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244
Engine Air Cleaner/Filter . . . . . . . . . 245
Cooling System . . . . . . . . . . . . . . . . . . . 246
Engine Overheating . . . . . . . . . . . . . . 250
Washer Fluid . . . . . . . . . . . . . . . . . . . . . 252
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . 253
Battery - North America . . . . . . . . . 254
All-Wheel Drive . . . . . . . . . . . . . . . . . . 255 Starter Switch Check . . . . . . . . . . . . . 255
Park Brake and P (Park)
Mechanism Check . . . . . . . . . . . . . . 256
Wiper Blade Replacement . . . . . . . 256
Windshield Replacement . . . . . . . . 257
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . 257
Headlamp Aiming
Front Headlamp Aiming . . . . . . . . . 258
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . . . . . 258
Halogen Bulbs . . . . . . . . . . . . . . . . . . . . 258
High Intensity Discharge (HID) Lighting . . . . . . . . . . . . . . . . . . . . . . . . . 259
LED Lighting . . . . . . . . . . . . . . . . . . . . . 259
Front Turn Signal Lamps . . . . . . . . 259
Electrical System
Electrical System Overload . . . . . . 259
Fuses and Circuit Breakers . . . . . . 260
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260
Instrument Panel Fuse Block . . . . 262
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267
All-Season Tires . . . . . . . . . . . . . . . . . . 268
Winter Tires . . . . . . . . . . . . . . . . . . . . . . 268
Run-Flat Tires . . . . . . . . . . . . . . . . . . . . 269 Self-Sealing Tires . . . . . . . . . . . . . . . . . 269
Low-Profile Tires . . . . . . . . . . . . . . . . . 270
Summer Tires . . . . . . . . . . . . . . . . . . . . 270
Tire Sidewall Labeling . . . . . . . . . . . 270
Tire Designations . . . . . . . . . . . . . . . . . 272
Tire Terminology and
Definitions . . . . . . . . . . . . . . . . . . . . . . 272
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . 275
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . . . . . . 276
Tire Pressure Monitor System . . . 276
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . . . . . . . . 277
Tire Inspection . . . . . . . . . . . . . . . . . . . 280
Tire Rotation . . . . . . . . . . . . . . . . . . . . . 281
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 282
Buying New Tires . . . . . . . . . . . . . . . . 282
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . . . . . . . . 284
Uniform Tire Quality Grading . . . 284
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . . . . . . . . 285
Wheel Replacement . . . . . . . . . . . . . . 286
Tire Chains . . . . . . . . . . . . . . . . . . . . . . . 286
If a Tire Goes Flat . . . . . . . . . . . . . . . . 287Jump Starting
Jump Starting - North America . . . . . . . . . . . . . . . . . . . . . . . . . 288

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
VEHICLE CARE 253
Caution
Continuing to drive with worn-out
brake pads could result in costly
brake repair.
Some driving conditions or climates
can cause a brake squeal when the
brakes are first applied or lightly
applied. This does not mean
something is wrong with the brakes.
If equipped with high performance
brake linings, there could be an
increased build-up of brake dust as
well as minor noises as compared to
standard brake linings.
Properly torqued wheel nuts are
necessary to help prevent brake
pulsation. When tires are rotated,
inspect brake pads for wear and
evenly tighten wheel nuts in the
proper sequence to torque
specifications. See Capacities and
Specifications 0318.
Brake pads should be replaced as
complete axle sets.
Brake Pedal Travel
See your dealer if the brake pedal does
not return to normal height, or if
there is a rapid increase in pedal
travel. This could be a sign that brake
service may be required.
Replacing Brake System Parts
Always replace brake system parts
with new, approved replacement parts.
If this is not done, the brakes may not
work properly. The braking
performance expected can change in
many other ways if the wrong
replacement brake parts are installed
or parts are improperly installed.
Brake Fluid
The brake master cylinder reservoir is
filled with GM approved DOT 3 brake
fluid as indicated on the reservoir cap.
See Engine Compartment Overview
0 238 for the location of the reservoir.
Checking Brake Fluid
With the vehicle in P (Park) on a level
surface, the brake fluid level should be
between the minimum and maximum
marks on the brake fluid reservoir.
There are only two reasons why the
brake fluid level in the reservoir may
go down:
. Normal brake lining wear. When
new linings are installed, the fluid
level goes back up.
. A fluid leak in the brake hydraulic
system. Have the brake hydraulic
system fixed. With a leak, the
brakes will not work well.
Always clean the brake fluid reservoir
cap and the area around the cap
before removing it.
Do not top off the brake fluid. Adding
fluid does not correct a leak. If fluid is
added when the linings are worn,
there will be too much fluid when

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
254 VEHICLE CARE
new brake linings are installed. Add or
remove fluid, as necessary, only when
work is done on the brake hydraulic
system.
{Warning
If too much brake fluid is added, it
can spill on the engine and burn,
if the engine is hot enough. You or
others could be burned, and the
vehicle could be damaged. Add
brake fluid only when work is done
on the brake hydraulic system.
When the brake fluid falls to a low
level, the brake warning light comes
on. See Brake System Warning Light
0 102.
Brake fluid absorbs water over time
which degrades the effectiveness of
the brake fluid. Replace brake fluid at
the specified intervals to prevent
increased stopping distance. See
Maintenance Schedule 0303. What to Add
Use only GM approved DOT 3 brake
fluid from a clean, sealed container.
See
Recommended Fluids and
Lubricants 0313.{Warning
The wrong or contaminated brake
fluid could result in damage to the
brake system. This could result in
the loss of braking leading to a
possible injury. Always use the
proper GM approved brake fluid.
Caution
If brake fluid is spilled on the
vehicle's painted surfaces, the paint
finish can be damaged. Immediately
wash off any painted surface.
Battery - North America
The original equipment battery is
maintenance free. Do not remove the
cap and do not add fluid. Refer to the replacement number
shown on the original battery label
when a new battery is needed.
The vehicle has an Absorbed Glass
Mat (AGM) 12-volt battery.
Installation of a standard 12-volt
battery will result in reduced 12-volt
battery life.
When using a 12-volt battery charger
on the 12-volt AGM battery, some
chargers have an AGM battery setting
on the charger. If available, use the
AGM setting on the charger, to limit
charge voltage to 14.8 volts. Follow
the charger manufacturer's
instructions.
Stop/Start System
This vehicle has a Stop/Start system
to shut off the engine to help
conserve fuel. See
Stop/Start System
0 161.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
VEHICLE CARE 259
High Intensity Discharge
(HID) Lighting
{Warning
The High Intensity Discharge (HID)
lighting system operates at a very
high voltage. If you try to service
any of the system components, you
could be seriously injured. Have
your dealer or a qualified technician
service them.
After an HID headlamp bulb has been
replaced, the beam might be a slightly
different shade than it was originally.
This is normal.
LED Lighting
This vehicle has several LED lamps.
For replacement of any LED lighting
assembly, contact your dealer.
Front Turn Signal Lamps
Uplevel
See your dealer for turn signal
replacement.
Base level
To replace one of these lamps: 1. Open the hood.
2. Turn the bulb socket counterclockwise to remove it
from the headlamp assembly.
3. Unplug the electrical connector from the bulb by releasing the
clip on the connector.
4. Replace the bulb and reverse Steps 1–3 to reinstall.
Electrical System
Electrical System Overload
The vehicle has fuses and circuit
breakers to protect against an
electrical system overload.
When the current electrical load is too
heavy, the circuit breaker opens and
closes, protecting the circuit until the
current load returns to normal or the
problem is fixed. This greatly reduces
the chance of circuit overload and fire
caused by electrical problems.
Fuses and circuit breakers protect
power devices in the vehicle.
Replace a bad fuse with a new one of
the identical size and rating.
If there is a problem on the road and
a fuse needs to be replaced, the
same amperage fuse can be borrowed.
Choose some feature of the vehicle
that is not needed to use and replace
it as soon as possible.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
VEHICLE CARE 261
Lift the fuse block cover to access the
fuses.
The vehicle may not be equipped with
all of the fuses and relays shown.
Caution
Spilling liquid on any electrical
component on the vehicle may
damage it. Always keep the covers
on any electrical component.
FusesUsage
1 Long range radar front sensor
2 Park/Daytime running lamps
3 Exterior lighting module 4
4 Exterior lighting module 7 Fuses
Usage
5 Headlamp level
6 –
7 Electronic brake control module
8 Washer pump
9 –
10 –
11 –

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
262 VEHICLE CARE
FusesUsage
12 Horn
13 Front wiper
14 Exterior lighting module 6
15 Exterior lighting module 1
16 Exterior lighting module 5
17 Exterior lighting module 3
18 Aero shutter
19 –
20 –
21 Virtual key system/ Power sounder
module
22 –
23 Transmission control module
24 Active engine mount
25 – Fuses
Usage
26 Engine control module
27 Injectors/Ignition 2
28 Charged air cooler
29 Transmission coolant pump
30 Injectors/Ignition 1
31 Emissions 1
32 Emissions 2
33 Starter solenoid
34 –
35 Coolant pump
36 Starter pinion
37 AC clutch
38 –
39 –
40 –
41 –
42 Water pump
43 – Fuses
Usage
44 –
Relays Usage
47 –
48 Front wiper speed
49 Front wiper control
51 –
52 Engine control module
53 Starter solenoid
54 Starter pinion
55 –
57 AC clutch
58 –
Instrument Panel Fuse
Block
The instrument panel fuse block is in
the end of the driver side of the
instrument panel.