check engine light CADILLAC CT4 2020 User Guide

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
INSTRUMENTS AND CONTROLS 107
Engine Oil Pressure Light
Caution
Lack of proper engine oil
maintenance can damage the
engine. Driving with the engine oil
low can also damage the engine.
The repairs would not be covered
by the vehicle warranty. Check the
oil level as soon as possible. Add oil
if required, but if the oil level is
within the operating range and the
oil pressure is still low, have the
vehicle serviced. Always follow the
maintenance schedule for changing
engine oil.
This light should come on briefly as
the engine is started. If it does not
come on, have the vehicle serviced by
your dealer.If the light comes on and stays on, it
means that oil is not flowing through
the engine properly. The vehicle could
be low on oil and might have some
other system problem. See your dealer.
Low Fuel Warning Light
This light is near the fuel gauge and
comes on briefly when the ignition is
turned on as a check to show it is
working.
It also comes on when the fuel tank is
low on fuel. The light turns off when
fuel is added. If it does not, have the
vehicle serviced.
Security Light
The security light should come on
briefly as the engine is started. If it
does not come on, have the vehicle
serviced by your dealer. If the system
is working normally, the indicator
light turns off.
If the light stays on and the engine
does not start, there could be a
problem with the theft-deterrent
system. See
Immobilizer Operation
0 24.
High-Beam On Light

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
114 INSTRUMENTS AND CONTROLS
Metric
English
Performance View : This displays
digital speed, indicators from speed
view along with rpm reading,
transmission positions, Shift Timing
Light Position (CT4-V only), and gear
shift indicator (if equipped). The shift timing lights at the top of
the display will appear with increases
in engine rpm. The rows of lights get
closer together as the shift point gets
closer. Shift the transmission before
the lights come together in the
display. Shift immediately if the lights
are flashing. See
Manual Mode
(Electronic Shifter) 0177 or
Manual Mode (Mechanical Shifter)
0 176.
Care of the HUD
Clean the inside of the windshield to
remove any dirt or film that could
reduce the sharpness or clarity of the
HUD image.
Clean the HUD lens with a soft cloth
sprayed with glass cleaner. Wipe the
lens gently, then dry it.
HUD Troubleshooting
If you cannot see the HUD image
when the ignition is on, check that:
.
Nothing is covering the HUD lens.
. The HUD brightness setting is not
too dim or too bright.
. The HUD is adjusted to the proper
height.
. Polarized sunglasses are not worn.
. The windshield and HUD lens are
clean.
If the HUD image is not correct,
contact your dealer.
The windshield is part of the HUD
system. If windshield replacement is
required, see Windshield Replacement
0 257.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
182 DRIVING AND OPERATING
When Automatic Vehicle Hold (AVH)
is turned on and the vehicle is braked
to a stop, AVH prevents the vehicle
from moving during the transition
from brake pedal release to accelerator
pedal apply. The brakes release when
the accelerator pedal is applied. The
brakes may also release under other
conditions. Do not rely on AVH to
hold the vehicle.
If the accelerator pedal is not applied
within a few minutes, the Electric
Parking Brake will apply. The parking
brake will also apply if the driver door
is opened or the driver seat belt is
unfastened while AVH is holding the
vehicle.
AVH can be turned on by pressing
AUTO HOLD. The indicator light on
the switch will come on. The AVH
light on the instrument panel will
come on while AVH is actively holding
the vehicle. SeeAutomatic Vehicle Hold
(AVH) Light 0103.Ride Control Systems
Traction Control/Electronic
Stability Control
The vehicle has a Traction Control
System (TCS) and StabiliTrak/
Electronic Stability Control (ESC).
These systems help limit wheel slip
and assist the driver in maintaining
control, especially on slippery road
conditions.
TCS activates if it senses that any of
the drive wheels are spinning or
beginning to lose traction. When this
happens, the system brakes the
spinning wheel(s) and/or reduces
engine power to limit wheel spin.
StabiliTrak/ESC activates when the
computer senses a difference between
the intended path and the direction
the vehicle is actually traveling.
StabiliTrak/ESC selectively applies
braking pressure at any one of the
vehicle's brakes to help steer the
vehicle in the intended direction. If cruise control is being used and TCS
or StabiliTrak/ESC begins to limit
wheel spin, cruise control will
disengage. Cruise control may be
turned back on when road conditions
allow.
Both systems come on automatically
when the vehicle is started and begins
to move. The systems may be heard or
felt while they are operating or while
performing diagnostic checks. This is
normal and does not mean there is a
problem with the vehicle.
It is recommended to leave both
systems on for normal driving
conditions, but It may be necessary to
turn TCS off if the vehicle gets stuck
in sand, mud, ice, or snow. See
If the
Vehicle Is Stuck 0153 and “Turning
the Systems Off and On ”later in this
section.

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
VEHICLE CARE 289
2.0L L4 Engine Shown, 2.7L L4 EngineSimilar
1. Discharged Battery Remote
Positive Terminal
2. Discharged Battery Negative Grounding Point
3. Good Battery Negative Terminal
4. Good Battery Positive Terminal
The jump start positive terminal (4)
and negative post (3) are on the
battery of the vehicle providing the
jump start. The jump start remote positive
terminal (1) and the remote negative
grounding point (2) for the discharged
battery are on the passenger side of
the vehicle.
The positive jump start connection for
the discharged battery is under a
cover. Lift the cover to expose the
terminal.
1. Check the other vehicle. It must have a 12-volt battery with a
negative ground system.
Caution
If the other vehicle does not have a
12-volt system with a negative
ground, both vehicles can be
damaged. Only use a vehicle that
has a 12-volt system with a
negative ground for jump starting.
2. Position the two vehicles so that they are not touching. 3. Set the parking brake firmly and
put the shift lever in P (Park)
with an automatic transmission,
or Neutral with a manual
transmission.
Caution
If any accessories are left on or
plugged in during the jump starting
procedure, they could be damaged.
The repairs would not be covered
by the vehicle warranty. Whenever
possible, turn off or unplug all
accessories on either vehicle when
jump starting.
4. Turn the ignition off. Turn off all lights and accessories in both
vehicles, except the hazard
warning flashers if needed.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
310 SERVICE AND MAINTENANCE
Additional Maintenance
and Care
Your vehicle is an important
investment and caring for it properly
may help to avoid future costly
repairs. To maintain vehicle
performance, additional maintenance
services may be required.
It is recommended that your dealer
perform these services—their trained
dealer technicians know your vehicle
best. Your dealer can also perform a
thorough assessment with a
multi-point inspection to recommend
when your vehicle may need
attention.
The following list is intended to
explain the services and conditions to
look for that may indicate services are
required.
Battery
The 12-volt battery supplies power to
start the engine and operate any
additional electrical accessories. .
To avoid break-down or failure to
start the vehicle, maintain a
battery with full cranking power.
. Trained dealer technicians have
the diagnostic equipment to test
the battery and ensure that the
connections and cables are
corrosion-free.
Belts
. Belts may need replacing if they
squeak or show signs of cracking
or splitting.
. Trained dealer technicians have
access to tools and equipment to
inspect the belts and recommend
adjustment or replacement when
necessary.
Brakes
Brakes stop the vehicle and are crucial
to safe driving.
. Signs of brake wear may include
chirping, grinding, or squealing
noises, or difficulty stopping. .
Trained dealer technicians have
access to tools and equipment to
inspect the brakes and recommend
quality parts engineered for the
vehicle.
Fluids
Proper fluid levels and approved fluids
protect the vehicle’s systems and
components. See Recommended Fluids
and Lubricants 0313 for GM approved
fluids.
. Engine oil and windshield washer
fluid levels should be checked at
every fuel fill.
. Instrument cluster lights may
come on to indicate that fluids
may be low and need to be filled.
Hoses
Hoses transport fluids and should be
regularly inspected to ensure that
there are no cracks or leaks. With a
multi-point inspection, your dealer
can inspect the hoses and advise if
replacement is needed.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
344 INDEX
IndexA
Accessories and Modifications . . . . . 235
Accessory Power . . . . . . . . . . . . . . . . . . . . 163
Active Fuel Management . . . . . . . . . . . 167
Adaptive Cruise Control . . . . . . . . . . . . 194
Add-On Electrical Equipment . . . . . . 231
Additional InformationOnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
Additional Maintenance and Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 310
Adjustments Lumbar, Front Seats . . . . . . . . . . . . . . . . 36
Thigh Support . . . . . . . . . . . . . . . . . . . . . . 36
Air Cleaner/Filter, Engine . . . . . . . . . . 245
Air Conditioning . . . . . . . . . . . . . . . . . . . . 134
Air Filter, Passenger
Compartment . . . . . . . . . . . . . . . . . . . . . 139
Air Vents . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
Airbag System Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
How Does an Airbag Restrain? . . . . . 55
Passenger Sensing System . . . . . . . . . 57
What Makes an Airbag Inflate? . . . . 55
What Will You See after anAirbag Inflates? . . . . . . . . . . . . . . . . . . . 56
When Should an Airbag Inflate? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Where Are the Airbags? . . . . . . . . . . . . 53 Airbags
Adding Equipment to the
Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Passenger Status Indicator . . . . . . . . . 99
Readiness Light . . . . . . . . . . . . . . . . . . . . . 98
Servicing Airbag-Equipped Vehicles . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
System Check . . . . . . . . . . . . . . . . . . . . . . . 51
Alarm Vehicle Security . . . . . . . . . . . . . . . . . . . . . 22
Alert
Lane Change . . . . . . . . . . . . . . . . . . . . . . 217
Rear Pedestrian . . . . . . . . . . . . . . . . . . . 209
Side Blind Zone (SBZA) . . . . . . . . . . 217
All-Season Tires . . . . . . . . . . . . . . . . . . . . . 268
All-Wheel Drive . . . . . . . . . . . . . . . .178, 255
Antilock Brake System (ABS) . . . . . . 179 Warning Light . . . . . . . . . . . . . . . . . . . . 103
Appearance Care Exterior . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293
Interior . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297
Assistance Systems for Driving . . . . 210
Assistance Systems for Parking and Backing . . . . . . . . . . . . . . . . . . . . . . . 204
Auto Stop
Stop/Start System . . . . . . . . . . . . . . . . 161
Automatic Dimming Mirrors . . . . . . . . . . . . . . . . . . . 27

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
INDEX 345
Automatic (cont'd)Door Locks . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Emergency Braking (AEB) . . . . . . . . 213
Headlamp System . . . . . . . . . . . . . . . . 128
Transmission . . . . . . . . . . . . . . . . . 169, 171
Transmission Fluid . . . . . . . . . . . . . . . 244
Vehicle Hold Light . . . . . . . . . . . . . . . . 103
Automatic Transmission Manual Mode . . . . . . . . . . . . . . . . 176, 177
Automatic Vehicle Hold (AVH) . . . . 181
B
Battery Exterior Lighting BatterySaver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
Load Management . . . . . . . . . . . . . . . . 131
Power Protection . . . . . . . . . . . . . . . . . . 132
Battery - North America . . . . . .254, 288
Blade Replacement, Wiper . . . . . . . . . 256
Brake Electric Boost . . . . . . . . . . . . . . . . . . . . . 179
Parking, Electric . . . . . . . . . . . . . . . . . . 179
System Warning Light . . . . . . . . . . . . 102
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252 Antilock . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
Assist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253
Braking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144 Braking (cont'd)
Automatic Emergency (AEB) . . . . . 213
Braking System Front Pedestrian (FPB) . . . . . . . . . . . 214
Break-In, New Vehicle . . . . . . . . . . . . . . 157
Bulb Replacement Front Turn Signal Lamps . . . . . . . . 259
Halogen Bulbs . . . . . . . . . . . . . . . . . . . . 258
Headlamp Aiming . . . . . . . . . . . . . . . . 258
Headlamps . . . . . . . . . . . . . . . . . . . . . . . . 258
High Intensity Discharge(HID) Lighting . . . . . . . . . . . . . . . . . . . 259
Buying New Tires . . . . . . . . . . . . . . . . . . . 282
C
Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
California Perchlorate MaterialsRequirements . . . . . . . . . . . . . . . . . . . 235
California Proposition 65 Warning . . . . . . . . . . . . .234, 254, 288, Back Cover
Canadian Vehicle Owners . . . . . . . . . . . . . 2
Capacities and Specifications . . . . . . 318
Carbon Monoxide Engine Exhaust . . . . . . . . . . . . . . . . . . . 168
Trunk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Winter Driving . . . . . . . . . . . . . . . . . . . . 152 Cargo
Management System . . . . . . . . . . . . . . . 84
Tie-Downs . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Caution, Danger, and Warning . . . . . . . . 3
Center Console Storage . . . . . . . . . . . . . . 83
Chains, Tire . . . . . . . . . . . . . . . . . . . . . . . . . 286
Charging Wireless . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
Charging System Light . . . . . . . . . . . . . . 99
Check Engine Light (Malfunction
Indicator) . . . . . . . . . . . . . . . . . . . . . . . . 100
Child Restraints Infants and Young Children . . . . . . . . 65
Lower Anchors and Tethers forChildren . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Older Children . . . . . . . . . . . . . . . . . . . . . . 63
Securing . . . . . . . . . . . . . . . . . . . . . . . . .76, 78
Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Circuit Breakers . . . . . . . . . . . . . . . . . . . . . 260
Cleaning Exterior Care . . . . . . . . . . . . . . . . . . . . . . 293
Interior Care . . . . . . . . . . . . . . . . . . . . . . 297
Climate Control Systems Dual Automatic . . . . . . . . . . . . . . . . . . . 134
Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
Cluster, Instrument . . . . . . . . . . . . . . . . . . 93
Collision Damage Repair . . . . . . . . . . . 328