light CADILLAC CT4 2023 Service Manual

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
116 Instruments and Controls
If the driver seat belt is
buckled, neither the light nor
the chime comes on.
Front Passenger Seat Belt
Reminder Light
The vehicle may have a front
passenger seat belt reminder
light near the passenger
airbag status indicator. See
Passenger Sensing System
066.
When the vehicle is started,
this light flashes and a chime
may come on to remind
passengers to fasten their
seat belt.
Then the light stays on solid
until the belt is buckled. This
cycle continues several times
if the front passenger remains
or becomes unbuckled while
the vehicle is moving. If the front passenger seat
belt is buckled, neither the
chime nor the light comes on.
The front passenger seat belt
reminder light and chime may
come on if an object is put on
the seat such as a briefcase,
handbag, grocery bag, laptop,
or other electronic device. To
turn off the reminder light
and/or chime, remove the
object from the seat or buckle
the seat belt.
Airbag Readiness
Light
This light shows if there is an
electrical problem with the
airbag system. It is located in
the instrument cluster. The
system check includes the
airbag sensor(s), the
passenger sensing system,
the pretensioners, the airbag
modules, the wiring, and the
crash sensing and diagnostic
module. For more information
on the airbag system, see
Airbag System
059.
The airbag readiness light
comes on for several seconds
when the vehicle is started.
If the light does not come on
then, have it fixed immediately.
{Warning
If the airbag readiness light
stays on after the vehicle is
started or comes on while
driving, it means the airbag
system might not be working
properly. The airbags in the
vehicle might not inflate in a
crash, or they could even
inflate without a crash. To
help avoid injury, have the
vehicle serviced right away.
If there is a problem with the
airbag system, a Driver
Information Center (DIC)
message may also come on.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Instruments and Controls 117
Passenger Airbag
Status Indicator
The vehicle has a passenger
sensing system. See
Passenger Sensing System
066 for important safety
information. The overhead
console has a passenger
airbag status indicator.
When the vehicle is started,
the passenger airbag status
indicator will light ON and OFF,
and the symbols for on and
off, for several seconds as a
system check. Then, after
several more seconds, the
status indicator will light either
ON or OFF, and either the
symbol for on or off, to let you
know the status of the front
outboard passenger frontal
airbag and knee airbag. If the word ON, and the on
symbol, is lit on the passenger
airbag status indicator, it
means that the front outboard
passenger frontal airbag and
knee airbag are allowed to
inflate.
If the word OFF, and the off
symbol, is lit on the passenger
airbag status indicator, it
means that the passenger
sensing system has turned off
the front outboard passenger
frontal airbag and knee airbag.
If, after several seconds, all of
the symbols remain lit, or if no
symbols are lit, or if the airbag
readiness light is on, there
may be a problem with the
lights or the passenger
sensing system. See your
dealer for service right away.
{Warning
If the airbag readiness light
ever comes on and stays on,
it means that something may
be wrong with the airbag
(Continued)
Warning (Continued)
system. To help avoid injury
to yourself or others, have
the vehicle serviced right
away. See Airbag Readiness
Light0116 for more
information, including
important safety
information.
Charging System
Light
The charging system light
comes on briefly when the
ignition is turned on, but the
engine is not running, as a
check to show the light is
working. It should go out when
the engine is started.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
118 Instruments and Controls
If the light stays on, or comes
on while driving, there may be
a problem with the electrical
charging system. Have it
checked by your dealer.
Driving while this light is on
could drain the battery.
When this light comes on, or is
flashing, the Driver Information
Center (DIC) also displays a
message.
If a short distance must be
driven with the light on, be
sure to turn off all
accessories, such as the radio
and air conditioner. Find a safe
place to stop the vehicle.
Malfunction Indicator
Lamp (Check Engine
Light)
This light is part of the
vehicle’s emission control
on-board diagnostic system.
If this light is on while the
engine is running, a
malfunction has been
detected and the vehicle mayrequire service. The light
should come on to show that it
is working when the ignition is
in Service Mode. See Ignition
Positions
0261.
Malfunctions are often
indicated by the system
before any problem is
noticeable. Being aware of the
light and seeking service
promptly when it comes on
may prevent damage.
Caution
If the vehicle is driven
continually with this light on,
the emission control system
may not work as well, the
fuel economy may be lower,
and the vehicle may not run
smoothly. This could lead to
(Continued)
Caution (Continued)
costly repairs that might not
be covered by the vehicle
warranty.
Caution
Modifications to the engine,
transmission, exhaust,
intake, or fuel system, or the
use of replacement tires
that do not meet the original
tire specifications, can cause
this light to come on. This
could lead to costly repairs
not covered by the vehicle
warranty. This could also
affect the vehicle’s ability to
pass an Emissions
Inspection/Maintenance
test. See Accessories and
Modifications0370.
If the light is flashing : A
malfunction has been
detected that could damage
the emission control system

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 123
Automatic Emergency
Braking (AEB)
Disabled Light
This indicator displays when
you turn off Automatic
Emergency Braking (AEB) or
Front Pedestrian
Braking (FPB).
This indicator will also display
if AEB or FPB is unavailable
due to malfunction, weather
conditions, or if the windshield
is not clean.
See Automatic Emergency
Braking (AEB)0345.
See Front Pedestrian Braking
(FPB) System 0346.
Vehicle Ahead
Indicator
If equipped, this indicator will
display green when a vehicle is
detected ahead and amber
when you are following a
vehicle ahead much too
closely.
See Forward Collision Alert
(FCA) System 0342.
Pedestrian Ahead
Indicator
If equipped, this indicator will
display amber when a nearby
pedestrian is detected in front
of the vehicle.
See Front Pedestrian Braking
(FPB) System 0346.
Traction Off 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.
The traction off light comes on
when the Traction Control
System (TCS) has been turned
off. If StabiliTrak/Electronic
Stability Control (ESC) is

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
124 Instruments and Controls
turned off, TCS is also turned
off. To turn TCS and ESC off
and on, see Traction Control/
Electronic Stability Control
0290.
If TCS is off, wheel slip during
acceleration is not limited
unless necessary to help
protect the driveline from
damage. Adjust driving
accordingly.
StabiliTrak OFF 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.
This light comes on when the
StabiliTrak/Electronic Stability
Control (ESC) system is turned off. If StabiliTrak/ESC is off,
the Traction Control System
(TCS) is also off. To turn ESC
off and on, see Traction
Control/Electronic Stability
Control
0290.
If ESC and TCS are off, the
systems do not assist in
controlling the vehicle. Adjust
driving accordingly.
Traction Control
System (TCS)/
StabiliTrak 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 light is on and not
flashing, the TCS and
potentially the StabiliTrak/ESC
system are not fully
operational and may not assist
in maintaining control. Adjust
driving accordingly. If the
condition persists, see your
dealer as soon as possible.
A Driver Information Center
(DIC) message may display.
The light flashes when the
TCS and/or the StabiliTrak/
ESC system is actively
working.
See Traction Control/
Electronic Stability Control
0
290.
Engine Coolant
Temperature Warning
Light

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.