2021 CADILLAC CT4 ignition

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
DRIVING AND OPERATING 251
Ending Cruise Control
There are four ways to end cruise
control:
.Step lightly on the brake pedal.
.Press*.
.Shift the transmission to
N (Neutral).
.PressJ.
Erasing Speed Memory
The cruise control set speed is erased
from memory if
Jis pressed or if the
ignition is turned off.
Adaptive Cruise Control
(Advanced)
If equipped, Adaptive Cruise Control
(ACC) allows the cruise control set
speed and following gap to be
selected. Read this entire section
before using this system. The
following gap is the following time
between your vehicle and a vehicle
detected directly ahead in your path,
moving in the same direction. If no
vehicle is detected in your path, ACC works like regular cruise control. ACC
uses camera and radar sensors. See
Radio Frequency Statement
0409.
If a vehicle is detected in your path,
ACC can speed up the vehicle or apply
limited, moderate braking to maintain
the selected following gap. To
disengage ACC, apply the brake. If the
Traction Control System (TCS) or
StabiliTrak/Electronic Stability Control
(ESC) system activates while ACC is
engaged, ACC may automatically
disengage. See Traction Control/
Electronic Stability Control 0239. When
road conditions allow ACC to be safely
used, ACC can be turned back on. ACC
will not engage if the TCS or
StabiliTrak/ESC electronic stability
control system is disabled.
ACC can reduce the need for you to
frequently brake and accelerate,
especially when used on expressways,
freeways, and interstate highways.
When used on other roads, you may
need to take over the control of
braking or acceleration more often.
{Warning
ACC has limited braking ability and
may not have time to slow the
vehicle down enough to avoid a
collision with another vehicle you
are following. This can occur when
vehicles suddenly slow or stop
ahead, or enter your lane. Also see
“Alerting the Driver” in this section.
Complete attention is always
required while driving and you
should be ready to take action and
apply the brakes. See Defensive
Driving 0204.
{Warning
ACC will not detect or brake for
children, pedestrians, animals,
or other objects.
Do not use ACC when:
.On winding and hilly roads or
when the sensors are blocked by
snow, ice, or dirt. The system
(Continued)

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
DRIVING AND OPERATING 257
.Objects that are close to the front of
your vehicle.
ACC Automatically Disengages
ACC may automatically disengage and
you will need to manually apply the
brakes to slow the vehicle when:
.The sensors are blocked.
.The Traction Control System (TCS)
or StabiliTrak/ESC system has
activated or been disabled.
.There is a fault in the system.
.The radar falsely reports blockage
when driving in a desert or remote
area with no other vehicles or
roadside objects. A DIC message
may display to indicate that ACC is
temporarily unavailable.
The ACC indicator will turn white
when ACC is no longer active.
In some cases, when ACC will not
activate, regular Cruise Control may
be used. See “Switching Between ACC
and Regular Cruise Control ”previously
in this section. Always consider
driving conditions before using either
cruise control system. Notification to Resume ACC
ACC will maintain a follow gap behind
a detected vehicle and slow your
vehicle to a stop behind that vehicle.
If the stopped vehicle ahead has
driven away and ACC has not
resumed, the vehicle ahead indicator
will flash as a reminder to check
traffic ahead before proceeding. In
addition, the left and right sides of the
Safety Alert Seat will pulse three
times, or three beeps will sound. See
“Alert Type
”and “Adaptive Cruise Go
Notifier” in“Collision/Detection
Systems” underVehicle Personalization
0 117.
When the vehicle ahead drives away,
ACC resumes automatically if the stop
was brief. If necessary, press RES+ or
the accelerator pedal to resume ACC.
If stopped for more than two minutes
or if the driver door is opened and the
driver seat belt is unbuckled, the ACC
automatically applies the Electric
Parking Brake (EPB) to hold the
vehicle. The EPB status light will turn
on. See Electric Parking Brake 0237.
To release the EPB, press the
accelerator pedal. A DIC warning message may display
indicating to shift to P (Park) before
exiting the vehicle.
{Warning
If ACC has stopped the vehicle, and
if ACC is disengaged, turned off,
or canceled, the vehicle will no
longer be held at a stop. The vehicle
can move. When ACC is holding the
vehicle at a stop, always be
prepared to manually apply the
brakes.
{Warning
Leaving the vehicle without placing
it in P (Park) can be dangerous. Do
not leave the vehicle while it is
being held at a stop by ACC. Always
place the vehicle in P (Park) and
turn off the ignition before leaving
the vehicle.
ACC Override
If using the accelerator pedal while
ACC is active, the ACC indicator turns
blue on the instrument cluster and in

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
DRIVING AND OPERATING 259
guardrails, and other stationary
objects when entering or exiting a
curve. This is normal operation. The
vehicle does not need service.
Other Vehicle Lane Changes
ACC will not detect a vehicle ahead
until it is completely in the lane. The
brakes may need to be manually
applied.
Objects Not Directly in Front of Your
Vehicle
The detection of objects in front of
the vehicle may not be possible if:
.The vehicle or object ahead is not
within your lane.
.The vehicle ahead is shifted, not
centered, or is shifted to one side of
the lane.Driving in Narrow Lanes
Vehicles in adjacent traffic lanes or
roadside objects may be incorrectly
detected when located along the
roadway.
Do Not Use ACC on Hills and When
Towing a Trailer
Do not use ACC when driving on steep
hills or when towing a trailer. ACC will
not detect a vehicle in the lane while
driving on steep hills. If the brakes are
applied, ACC disengages.
Disengaging ACC
There are three ways to
disengage ACC:
.Step lightly on the brake pedal.
.Press*.
.PressJ.Erasing Speed Memory
The ACC set speed is erased from
memory if
Jis pressed or if the
ignition is turned off.
Weather Conditions Affecting ACC
System operation may be limited
under snow, heavy rain, or road spray
conditions.
Accessory Installations and Vehicle
Modifications
Do not install or place any object
around the front camera windshield
area that would obstruct the front
camera view.
Do not install objects on top of the
vehicle that overhang and obstruct the
front camera, such as a canoe, kayak,
or other items.
Do not modify the hood, headlamps,
or fog lamps, as this may limit the
camera’s ability to detect an object.
Cleaning the Sensing System
The camera sensor on the windshield
behind the rearview mirror and the
radar sensors on the front of the
vehicle can become blocked by snow,

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
DRIVING AND OPERATING 267
First Alert
.If the steering wheel light bar flashes green, the system has detected that your head and
eyes may not be directed toward the road.
.The flashing will stop when the system detects that your head and eyes appear to be
directed toward the road.
Second Alert
.If the steering wheel light bar flashes green for too long, Super Cruise will alert the driver
to take control of steering immediately by flashing the light bar red. Also, either beeps will
sound or the Safety Alert Seat will vibrate. See “Collision/Detection Systems”underVehicle
Personalization 0117.
.Take over steering, then Super Cruise will disengage.
.To re-engage Super Cruise, press]. See “Using Super Cruise ”previously in this section.
Third Alert
.If the steering wheel light bar flashes red for too long, a voice command will tell you to
take control of the vehicle.
.Take control of the steering immediately; ACC and Super Cruise will disengage.
.A DIC message will indicate that Super Cruise is locked out. Super Cruise cannot be
re-engaged until the next ignition cycle.
.Continued failure to take over steering will cause the vehicle to brake to a stop and OnStar
will be called. The brake lamps and hazard warning flashers will come on.
.Take control of the vehicle and continue driving.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
274 DRIVING AND OPERATING
Super Cruise Message Summary (cont'd)
Unavailable Sensor BlockedClear snow, ice, dirt, or other contaminants from the front
and rear areas of the vehicle.
Unavailable Sharp Curve Some curves are too sharp to be navigated by the Super
Cruise system. Super Cruise will be available after the curve
is traveled.
Super Cruise Unavailable Super Cruise is unavailable for reasons not described in
other messages.
Super Cruise Locked Out See Owner’s Manual The driver did not take control of the vehicle when
prompted by the Super Cruise system. The Super Cruise
system will be disabled until the ignition is turned off and
back on.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
320 VEHICLE CARE
{Warning
Steam and scalding liquids from a
hot cooling system are under
pressure. Turning the pressure cap,
even a little, can cause them to
come out at high speed and you
could be burned. Never turn the cap
when the cooling system, including
the pressure cap, is hot. Wait for
the cooling system and pressure
cap to cool.
Caution
Failure to follow the specific
coolant fill procedure could cause
the engine to overheat and could
cause system damage. If coolant is
not visible in the surge tank,
contact your dealer.If no problem is found, check to see if
coolant is visible in the coolant surge
tank. If coolant is visible but the
coolant level is not at or above the
indicated mark, add a 50/50 mixture
of clean, drinkable water and
DEX-COOL coolant at the coolant
surge tank, but be sure the cooling
system, including the coolant surge
tank pressure cap, is cool before you
do it.
2.0L L4 Engine
Automatic Coolant Service Fill
Instructions
The vehicle is equipped with a service
feature that assists with filling and
removing air from the cooling system
after service of components or when
coolant is added after being to low. To use this feature:
1. With a cold system, add coolant to
the indicated line on the
surge tank.
2. Replace the pressure cap on the surge tank.
3. Activate the service feature: 3.1. Connect the vehicle to a battery charger.
3.2. Turn the ignition to Service Mode. See Ignition Positions
0 219.
3.3. Turn off the air conditioning.
3.4. Set the parking brake.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
VEHICLE CARE 321
3.5. At the same time, press theaccelerator and the brake
pedal for two seconds, then
release.
3.6. At the end of the cycle, check the coolant level in the surge
tank and add coolant if it is
below the indicated line. Turn
the ignition off, allow the
Electronic Control Module
(ECM) to go to sleep, about
two minutes, and repeat
Steps 3.2 –3.6.
Listen for pump activation and
movement of the control valves while
watching the level of the coolant in
the surge tank. If the tank empties,
turn the ignition off, carefully remove
the pressure cap, refill to the indicated
line, replace the pressure cap, and
repeat steps 3.2 –3.6.
The fill and air removal process will
run for approximately 15 minutes.Caution
If the pressure cap is not tightly
installed, coolant loss and engine
damage may occur. Be sure the cap
is properly and tightly secured.
2.7L L4 Engine
Automatic Coolant Service Fill
Instructions
The vehicle is equipped with a service
feature that assists with filling and
removing air from the cooling system
after service of components or when
coolant is added after being to low.
To use this feature: 1. With a cold system unscrew the cooling system air bleeder cap.
If coolant can be seen through the
bleeder move to Step 3.
2. Add coolant through the surge tank until it is visible through the air
bleeder.
3. Replace the cooling system air bleeder cap.
4. Add coolant to the indicated line on the surge tank. 5. Replace the pressure cap on the
surge tank.
6. Activate the service feature: 6.1. Connect the vehicle to a battery charger.
6.2. Turn the ignition to Service Mode. See Ignition Positions
0 219.
6.3. Turn off the air conditioning.
6.4. Set the parking brake.
6.5. At the same time, press the accelerator and the brake
pedal for two seconds, then
release.
6.6. At the end of the cycle, check the coolant level in the surge
tank and add coolant if it is
below the indicated line. Turn
the ignition off, carefully
remove the pressure cap, refill
to the indicated line, replace
the pressure cap, and repeat
steps 6.2 –6.6.
Listen for pump activation and
movement of the control valves while
watching the level of the coolant in
the surge tank. If the tank empties,
turn the ignition off, carefully remove

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
324 VEHICLE CARE
Caution
Continuing to drive with worn-out
brake linings could result in costly
brake repairs.
Some driving conditions or climates
can cause a brake squeal when the
brakes are first applied, clearing up
following several applications. This
does not mean something is wrong
with the brakes.
Properly torqued wheel nuts are
necessary to help prevent brake
pulsation. When tires are rotated,
inspect brake linings for wear and
evenly tighten wheel nuts in the
proper sequence to torque
specifications. See Capacities and
Specifications 0396.
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 can change in many
ways if the wrong brake parts are
installed or if parts are improperly
installed.
Brake Pad Life System (If
Equipped)
When to Change Brake Pads
This vehicle has a system that
estimates the remaining life of the
front and rear brake pads. Brake pad
life is displayed in the Driver
Information Center (DIC), along with
a percentage for each axle. The system
must be reset every time the brake
pads are changed.
When the system has determined that
the brake pads need to be replaced, a
message will display, which may
include mileage remaining.
Brake pads should always be replaced
as complete axle sets.
How to Reset the Brake Pad Life
System
The system will automatically detect
when significantly worn brake pads
and sensors are replaced. When the
ignition is turned on after new pads
and sensors are installed, a message
will display. Follow the prompts to
reset the system.
The brake pad life system can also be
manually reset: 1. Display Brake Pad Life on the DIC. See Driver Information Center (DIC)
(Base Level) 0107 or
Driver Information Center (DIC)
(Uplevel) 0110.
2. Press the thumbwheel. Select front or rear pads as appropriate.
3. Select YES on the confirmation message. Repeat for pads on the
other axle if they were also
replaced.