2023 CADILLAC CT4 service

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Instruments and Controls 119
and increase vehicle
emissions. Diagnosis and
service may be required.
To help prevent damage,
reduce vehicle speed and
avoid hard accelerations and
uphill grades. If towing a
trailer, reduce the amount of
cargo being hauled as soon as
possible.
If the light continues to flash,
find a safe place to park. Turn
the vehicle off and wait at
least 10 seconds before
restarting the engine. If the
light is still flashing, follow the
previous guidelines and see
your dealer for service as
soon as possible.
If the light is on steady :A
malfunction has been
detected. Diagnosis and
service may be required.
Check the following:
.If fuel has been added to the
vehicle using the capless fuel
funnel adapter, make sure
that it has been removed. See
“Filling the Tank with a
Portable Gas Can” under
Filling the Tank 0356. The
diagnostic system can
detect if the adapter has
been left installed in the
vehicle, allowing fuel to
evaporate into the
atmosphere. A few driving
trips with the adapter
removed may turn off the
light.
.Poor fuel quality can cause
inefficient engine operation
and poor driveability, which
may go away once the
engine is warmed up. If this
occurs, change the fuel
brand. It may require at least
one full tank of the proper
fuel to turn the light off. See
Recommended Fuel (LSY
2.0L L4 Turbo Engine) 0354
or
Recommended Fuel (L3B
2.7L L4 Turbo and LF4 3.6L
V6 Twin Turbo Engines)
0 355.
If the light remains on, see
your dealer.
Emissions Inspection and
Maintenance Programs
If the vehicle requires an
Emissions Inspection/
Maintenance test, the test
equipment will likely connect
to the vehicle's Data Link
Connector (DLC).
The DLC is under the
instrument panel to the left of
the steering wheel.
Connecting devices that are
not used to perform an
Emissions Inspection/
Maintenance test or to service
the vehicle may affect vehicle
operation. See Add-On
Electrical Equipment 0366.
See your dealer if assistance
is needed.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
120 Instruments and Controls
The vehicle may not pass
inspection if:
.The light is on when the
engine is running.
.The light does not come on
when the ignition is in
Service Mode.
.Critical emission control
systems have not been
completely diagnosed. If this
happens, the vehicle would
not be ready for inspection
and might require
several days of routine
driving before the system is
ready for inspection. This
can happen if the 12-volt
battery has recently been
replaced or run down, or if
the vehicle has been
recently serviced.
See your dealer if the vehicle
will not pass or cannot be
made ready for the test.
Brake System
Warning Light
MetricEnglish
This light comes on briefly
when the vehicle is turned on
to show that the light is
working. If it does not come on
then, have it fixed so it will be
ready to warn you if there is a
problem.
If the light comes on and stays
on, there is a brake problem.
Have the brake system
inspected right away. This
light may come on if the brake
fluid is low. See Brake Fluid
0 398.
If the light comes on while
driving, pull off the road and
stop carefully. The brake
system has electric brake
boost. Vehicle speed may be limited when the brake system
warning light comes on. The
brake pedal might be harder to
push, or the brake pedal may
go closer to the floor. It could
take longer to stop. If the light
is still on, have the vehicle
towed for service. See
Transporting a Disabled
Vehicle (Electronic Shifter)
0
450 or
Transporting a Disabled
Vehicle (Mechanical Shifter)
0 452.
{Warning
The brake system might not
be working properly if the
brake system warning light
is on. Driving with the brake
system warning light on can
lead to a crash. If the light is
still on after the vehicle has
been pulled off the road and
carefully stopped, have the
vehicle towed for service.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Instruments and Controls 121
Electric Parking Brake
Light
MetricEnglish
This light comes on when the
parking brake is applied. If the
light continues flashing after
the parking brake is released,
or while driving, there is a
problem with the Electric
Parking Brake system.
A message may also display in
the Driver Information
Center (DIC).
If the light does not come on,
or remains flashing, see your
dealer.
Service Electric
Parking Brake Light
This light may come on briefly
when the vehicle is turned on.
If it does not come on, have it
fixed so it will be ready to
warn if there is a problem.
If this light stays on or comes
on while driving, there is a
problem with the Electric
Parking Brake (EPB). Take the
vehicle to a dealer as soon as
possible. In addition to the
parking brake, other safety
functions that utilize the EPB
may also be degraded.
A message may also display in
the Driver Information Center
(DIC). See Electric Parking
Brake 0287.
Antilock Brake
System (ABS)
Warning Light
This light comes on briefly
when the vehicle is turned on
to show that the light is
working. If it does not come on
then, have it fixed so it will be
ready to warn you if there is a
problem.
If the ABS warning light stays
on, or comes on again while
driving, the vehicle needs
service. A chime may also
sound when the light stays on.
If the ABS warning light is the
only light on, the vehicle has
regular brakes, but ABS is not
functioning.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
122 Instruments and Controls
If both the ABS warning light
and the brake system warning
light are on, ABS is not
functioning and there is a
problem with the regular
brakes. See your dealer for
service.
See Brake System Warning
Light0120.
Performance Shifting
Light
If equipped, this light may
display green when Sport
Mode is activated and certain
driving conditions are met.
Sport Mode detects when the
vehicle is being driven in a
competitive manner, and
adjusts the shifting of the
gears accordingly. See Driver
Mode Control 0292.
Automatic Vehicle
Hold (AVH) Light
This light comes on when AVH
is turned on. See Automatic
Vehicle Hold (AVH) 0289.
Lane Keep Assist
(LKA) Light
Base LevelUplevel
If equipped, the Lane Keep
Assist Light may display the
following colors:
.Blank: LKA is disabled.
.White: Appears when the
vehicle starts. A steady
white light indicates that
LKA is not ready to assist.
.Green: Appears when LKA is
turned on and ready to
assist. LKA will gently turn
the steering wheel if the
vehicle approaches a
detected lane marking.
.Amber: Appears when LKA is
active. The light flashes
amber as a Lane Departure
Warning (LDW) alert to
indicate that the lane
marking has been
unintentionally crossed.
If the system detects you
are steering intentionally (to
pass or change lanes), the
LDW alert may not display.
LKA will not assist or alert if
the turn signal is active in the
direction of lane departure,
or if LKA detects that you are
accelerating, braking,
or actively steering. See Lane
Keep Assist (LKA) 0351.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Instruments and Controls 125
On some vehicles this light
comes on briefly while starting
the vehicle. If it does not, have
the vehicle serviced by the
dealer. If the system is
working normally the indicator
light goes off. For vehicles
with the reconfigurable
cluster, this light may not
come on when starting the
vehicle.
Caution
The engine coolant
temperature warning light
indicates that the vehicle
has overheated. Driving with
this light on can damage the
engine and it may not be
covered by the vehicle
warranty. See Engine
Overheating0391.
The engine coolant
temperature warning light
comes on when the engine has
overheated. If this happens pull over and
turn off the engine as soon as
possible. See Engine
Overheating
0391.
Driver Mode Control
Light
This light comes on when
Sport Mode is selected.
This light comes on when
Track Mode is selected. See
Driver Mode Control 0292.
This light comes on when
Snow/Ice Mode is selected.
This light comes on when V
Mode is selected. See Driver
Mode Control 0292.
This light comes on when My
Mode is selected. See Driver
Mode Control 0292.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Instruments and Controls 127
When the Light Flashes First
and Then Is On Steady
If the light flashes for about a
minute and then stays on,
there may be a problem with
the TPMS. If the problem is
not corrected, the light will
come on every time the
vehicle is started. See Tire
Pressure Monitor Operation
0425.
Engine Oil Pressure
Light
Caution
Driving the vehicle with low
engine oil pressure can
damage the engine and the
repairs would not be
covered by the vehicle
warranty.
If the engine oil pressure
light comes on while driving:
1. Stop in a safe location and turn off the engine.
(Continued)
Caution (Continued)
2. Check the oil level. SeeEngine Oil 0378.
3. Add oil if the oil level is below the normal
operating range.
4. Restart the vehicle. If the engine oil pressure light
stays on for more than
10 seconds, turn the
vehicle back off. Do not
restart the vehicle. See
your dealer for service.
This light should come on
briefly when the engine starts.
When the engine is off and the
vehicle is on, the light should
remain illuminated. If it does
not come on under either
condition, contact your dealer. If the light comes on and stays
on when the engine is running,
it may not have adequate oil
pressure. The oil level may be
low or there may be some
other oil system problem. Turn
the engine off when it is safe
to do so and contact your
dealer.
Low Fuel Warning
Light
A Low Fuel Warning Light
near the fuel gauge comes on
briefly when the ignition is
turned on as a check to show
it is working.
It also comes on when the fuel
gauge indicator nears empty.
The light turns off when fuel is
added. If it does not, have the
vehicle serviced.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
128 Instruments and Controls
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 Operation027.
High-Beam On Light
This light comes on when the
high-beam headlamps are in
use. See Headlamp High/
Low-Beam Changer 0147.
IntelliBeam Light
This light comes on when the
IntelliBeam system,
if equipped, is enabled. See
Exterior Lamp Controls 0145.
Lamps On Reminder
This light comes on when the
exterior lamps are in use,
except when only the Daytime Running Lamps (DRL) are
active. See Exterior Lamp
Controls
0145.
Cruise Control Light
The cruise control light is
white when the cruise control
is on and ready, and turns
green when the cruise control
is set and active.
See Cruise Control 0301.
Adaptive Cruise Control
Light
Base LevelUplevel

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
140 Instruments and Controls
Navigation Overlay :This
displays digital speed for
Tour/ Sport, current gear for
Track, indicators from speed
view along with Turn-by-Turn
Navigation information in
some vehicles. The compass
heading is displayed when
navigation routing is not
active.
Navigation Turn-by-Turn
Alerts shown in the instrument
cluster may also be displayed
in any HUD view.
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
0 401.
Vehicle Messages
Messages displayed on the
Driver Information Center
(DIC) indicate the status of the
vehicle or some action that may be needed to correct a
condition. Multiple messages
may appear one after another.
The messages that do not
require immediate action can
be acknowledged and cleared
by pressing the thumbwheel.
The messages that require
immediate action cannot be
cleared until that action is
performed.
All messages should be taken
seriously; clearing the
message does not correct the
problem.
If a SERVICE message
appears, see your dealer.
Follow the instructions given
in the messages. The system
displays messages regarding
the following topics:
.Service Messages
.Fluid Levels
.Vehicle Security
.Brakes
.Steering
.Ride Control Systems