2021 CADILLAC CT4 ECU

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
6 KEYS, DOORS, AND WINDOWS
Keys, Doors, and
Windows
Keys and Locks
Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Remote Keyless Entry (RKE)System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Remote Keyless Entry (RKE) System Operation . . . . . . . . . . . . . . . . . 7
Remote Vehicle Start . . . . . . . . . . . . . . 13
Door Locks . . . . . . . . . . . . . . . . . . . . . . . . . 15
Power Door Locks . . . . . . . . . . . . . . . . . 17
Delayed Locking . . . . . . . . . . . . . . . . . . . 17
Automatic Door Locks . . . . . . . . . . . . 17
Lockout Protection . . . . . . . . . . . . . . . . 18
Safety Locks . . . . . . . . . . . . . . . . . . . . . . . . 18
Doors
Trunk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Vehicle Security
Vehicle Security . . . . . . . . . . . . . . . . . . . . 20
Vehicle Alarm System . . . . . . . . . . . . . 20
Immobilizer . . . . . . . . . . . . . . . . . . . . . . . . 22
Immobilizer Operation . . . . . . . . . . . . 23
Exterior Mirrors
Convex Mirrors . . . . . . . . . . . . . . . . . . . . 23
Power Mirrors . . . . . . . . . . . . . . . . . . . . . . 24
Folding Mirrors . . . . . . . . . . . . . . . . . . . . 24
Heated Mirrors . . . . . . . . . . . . . . . . . . . . . 25
Automatic Dimming Mirror . . . . . . . 25
Reverse Tilt Mirrors . . . . . . . . . . . . . . . 25
Interior Mirrors
Interior Rearview Mirrors . . . . . . . . . 26
Manual Rearview Mirror . . . . . . . . . . 26
Automatic Dimming Rearview Mirror . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Windows
Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Power Windows . . . . . . . . . . . . . . . . . . . . 26
Sun Visors . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Roof
Sunroof . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Keys and Locks
Keys
{Warning
Leaving children in a vehicle with a
remote key is dangerous and
children or others could be
seriously injured or killed. They
could operate the power windows
or other controls or make the
vehicle move. The windows will
function with the remote key in the
vehicle, and children or others
could be caught in the path of a
closing window. Do not leave
children in a vehicle with a
remote key.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
KEYS, DOORS, AND WINDOWS 11
Programming Remote Keys to
the Vehicle
Only remote keys programmed to the
vehicle will work. If a remote key is
lost or stolen, a replacement can be
purchased and programmed through
your dealer. The vehicle can be
reprogrammed so that lost or stolen
remote keys no longer work. Each
vehicle can have up to eight remote
keys matched to it.
Programming with Recognized
Remote Keys
A new key can be programmed to the
vehicle when there are two
recognized keys.
To program, the vehicle must be in
RUN and both the recognized and new
remote keys must be with you.1. Place the two recognized remote keys on the passenger seat.
2. Scroll to the DIC menu to "Remote Key Relearn" and select.
The DIC displays READY FOR
REMOTE #3, 4, 5, etc.
3. Place the new remote key into therear cupholder.
4. Press ENGINE START/STOP. When the remote key is learned the DIC
display will show that it is ready to
program the next remote key.
5. Remove the remote key from the rear cupholder and press
KorQ
on the remote key.
To program additional remote keys,
repeat Steps 4–5. When all additional remote keys
are programmed, press and hold
ENGINE START/STOP for
approximately 12 seconds to exit
programming mode.
Programming without Recognized
Remote Keys
If two currently recognized remote
keys are not available, see your dealer
to program new remote keys.
Starting the Vehicle with a Low
Remote Key Battery
For improved vehicle security, the
remote key is equipped with a motion
sensor. When starting the vehicle,
if the remote key has been idle for a
while, the DIC may display KEY IN
SLEEP MODE, MOVE KEY, THEN
START. Move the remote key slightly
and try starting the vehicle. When
starting the vehicle, if the remote key
battery is depleted or there is signal
interference, the DIC may display NO
KEY FOUND, REPLACE BATTERY IN
KEY or NO REMOTE KEY WAS
DETECTED PLACE KEY IN KEY

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
KEYS, DOORS, AND WINDOWS 17
4. Release the door handle.
5. Check that the cap is secure.
Free-Turning Locks
The door key lock cylinder turns freely
when either the wrong mechanical key
is used, or the correct mechanical key
is not fully inserted. The free-turning
door lock feature prevents the lock
from being forced open. To reset the
lock, turn it to the vertical position
with the correct mechanical key fully
inserted. Remove the mechanical key
and insert it again. If this does not
reset the lock, turn the mechanical
key halfway around in the cylinder
and repeat the reset procedure.Power Door Locks
Q: Press to lock the doors. The
indicator light in the switch will
illuminate when locked.
K: Press to unlock the doors.
If equipped, the fuel door is also
locked or unlocked using these
features.
Delayed Locking
This feature delays the actual locking
of the doors until five seconds after all
doors are closed. When
Qis pressed on the power door
lock switch with the door open, a
chime will sound three times
indicating that delayed locking is
active.
The doors will then lock automatically
five seconds after all doors are closed.
If a door is reopened before
five seconds have elapsed, the
five-second timer will reset once all
the doors are closed again.
Press
Qon the door lock switch again,
or press
Qon the key, to override this
feature and lock the doors
immediately.
Delayed locking can be programmed.
See Vehicle Personalization 0117.
Automatic Door Locks
The doors will lock automatically
when all doors are closed, the ignition
is on, and the vehicle is shifted out of
P (Park).
If a vehicle door is unlocked, and then
opened and closed, the doors will lock
either when your foot is removed from
the brake or the vehicle speed
becomes faster than 13 km/h (8 mph).

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
20 KEYS, DOORS, AND WINDOWS
Close the trunk by pulling on the
handle. Do not use the handle as a
tie-down. Do not press the touch pad
while closing the trunk; this will cause
the trunk lid to be unlatched.
The trunk has an electric latch. If the
vehicle has lost power or the battery
is disconnected, the trunk will not
open. If this happens, use the
emergency trunk release handle.
Emergency Trunk Release
HandleCaution
Do not use the emergency trunk
release handle as a tie-down or
anchor point when securing items
in the trunk as it could damage the
handle.
There is a glow-in-the-dark emergency
trunk release handle on the trunk lid.
This handle will glow following
exposure to light. Pull the release
handle to open the trunk from the
inside.
Vehicle Security
This vehicle has theft-deterrent
features; however, they do not make
the vehicle impossible to steal.
Vehicle Alarm System
This vehicle has an anti-theft alarm
system.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
KEYS, DOORS, AND WINDOWS 21
The indicator light, on the instrument
panel near the windshield, indicates
the status of the system.
Off :Alarm system is disarmed.
On Solid : Vehicle is secured during
the delay to arm the system.
Fast Flash : Vehicle is unsecured.
A door, the hood, or the trunk is open.
Slow Flash : Alarm system is armed.
Arming the Alarm System
1. Turn off the vehicle.
2. Lock the vehicle in one of
three ways:
.Use the remote key.
.Use the Keyless Access system.
.With a door open, pressQon
the interior of the door.
3. After 30 seconds the alarm system will arm, and the indicator light
will begin to slowly flash indicating
the alarm system is operating.
Pressing
Qon the remote key a
second time will bypass the
30-second delay and immediately
arm the alarm system.
The vehicle alarm system will not arm
if the doors are locked with the
mechanical key.
If the driver door is opened without
first unlocking with the remote key,
the horn will chirp and the lights will
flash to indicate pre-alarm. If the
vehicle is not started, or the door is
not unlocked by pressing
Kon the
remote key during the 10-second
pre-alarm, the alarm will be activated.
The alarm will also be activated if a
passenger door, the trunk, or the hood
is opened without first disarming the
system. When the alarm is activated,
the turn signals flash and the horn sounds for about 30 seconds. The
alarm system will then re-arm to
monitor the next unauthorized event.
Disarming the Alarm System
To disarm the alarm system or turn
off the alarm if it has been activated:
.PressKon the remote key.
.Unlock the vehicle using the Keyless
Access system.
.Start the vehicle.
To avoid setting off the alarm by
accident:
.Lock the vehicle after all occupants
have left the vehicle and all doors
are closed.
.Always unlock a door with the
remote key or use the Keyless
Access system.
Unlatching the driver door with the
mechanical key will not disarm the
system or turn off the alarm.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
22 KEYS, DOORS, AND WINDOWS
How to Detect a Tamper
Condition
IfKis pressed on the remote key and
the horn chirps and the lights flash
three times, a previous alarm occurred
while the system was armed.
If the alarm has been activated, a
message will appear on the DIC.
Power Sounder, Inclination
Sensor, and Intrusion Sensor
In addition to the standard
theft-deterrent system features, this
system may also have a power
sounder, inclination sensor, and
intrusion sensor.
The power sounder provides an
audible alarm which is distinct from
the vehicle’s horn. It has its own
power source, and can sound an alarm
if the vehicle’s battery is
compromised.
The inclination sensor can set off the
alarm if it senses movement of the
vehicle, such as when a tire is
removed. Make sure the vehicle's
alarm is not armed prior to any
jacking. The intrusion sensor monitors the
vehicle interior, and can activate the
alarm if it senses unauthorized entry
into the vehicle's interior. Do not allow
passengers or pets to remain in the
vehicle when the intrusion sensor is
activated.
Before arming the theft-deterrent
system and activating the intrusion
sensor:
.Make sure all doors and windows
are completely closed.
.Secure any loose items such as sun
glasses.
.Make sure there are no obstructions
blocking the sensors in the front
overhead console.
Inclination and Intrusion Sensor
Disable SwitchIt is recommended that the intrusion
and inclination sensor be deactivated
if pets are left in the vehicle or the
vehicle is being transported. With the
vehicle turned off, press
oin the
front overhead console. The indicator
light will come on momentarily,
indicating that these sensors have
been disabled for the next alarm
system arming cycle.
Immobilizer
See Radio Frequency Statement 0409.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
KEYS, DOORS, AND WINDOWS 23
Immobilizer Operation
This vehicle has a passive
theft-deterrent system.
The system does not have to be
manually armed or disarmed.
The vehicle is automatically
immobilized when the vehicle is
turned off.
The immobilization system is
disarmed when the ignition is turned
on or to ACC/ACCESSORY and a valid
remote key is present in the vehicle.
The security light, in the instrument
cluster, comes on if there is a problem
with arming or disarming the
theft-deterrent system.
The system has one or more remote
keys matched to an immobilizer
control unit in the vehicle. Only a
correctly matched remote key willstart the vehicle. If the remote key is
ever damaged, you may not be able to
start your vehicle.
When trying to start the vehicle, the
security light may come on briefly.
If the engine does not start and the
security light stays on, there is a
problem with the system. Turn the
ignition off and try again.
If the vehicle will not change ignition
modes (ACC/ACCESSORY, on, off), and
the remote key appears to be
undamaged, try another remote key.
Or, you may try placing the remote
key in the backup location. See
Remote Keyless Entry (RKE) System
Operation
07.
If the ignition modes will not change
with the other remote key or in the
backup location, the vehicle needs
service. If the ignition does change
modes, the first remote key may be
faulty. See your dealer.
It is possible for the immobilizer
system to learn new or replacement
remote keys. Up to eight remote keys
can be programmed for the vehicle. To
program additional remote keys, see “Programming Remote Keys to the
Vehicle
”under Remote Keyless Entry
(RKE) System Operation 07.
Do not leave the remote key or device
that disarms or deactivates the
theft-deterrent system in the vehicle.
Exterior Mirrors
Convex Mirrors
{Warning
A convex mirror can make things,
like other vehicles, look farther
away than they really are. If you cut
too sharply into the right lane, you
could hit a vehicle on the right.
Check the inside mirror or glance
over your shoulder before changing
lanes.
The passenger side mirror is convex
shaped. A convex mirror's surface is
curved so more can be seen from the
driver seat.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
30 SEATS AND RESTRAINTS
Seats and Restraints
Head Restraints
Head Restraints . . . . . . . . . . . . . . . . . . . . 31
Front Seats
Power Seat Adjustment . . . . . . . . . . . 32
Lumbar Adjustment . . . . . . . . . . . . . . . 32
Thigh Support Adjustment . . . . . . . . 33
Reclining Seatbacks . . . . . . . . . . . . . . . 33
Memory Seats . . . . . . . . . . . . . . . . . . . . . . 34
Heated and Ventilated FrontSeats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Massage . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Rear Seats
Rear Seats . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Seat Belts
Seat Belts . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Buckle To Drive . . . . . . . . . . . . . . . . . . . . 41
How to Wear Seat Belts Properly . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Lap-Shoulder Belt . . . . . . . . . . . . . . . . . . 44
Seat Belt Use During Pregnancy . . . . . . . . . . . . . . . . . . . . . . . . . 46 Seat Belt Extender . . . . . . . . . . . . . . . . . 46
Safety System Check . . . . . . . . . . . . . . 47
Seat Belt Care . . . . . . . . . . . . . . . . . . . . . . 47
Replacing Seat Belt System Parts
after a Crash . . . . . . . . . . . . . . . . . . . . . . 47
Airbag System
Airbag System . . . . . . . . . . . . . . . . . . . . . 48
Where Are the Airbags? . . . . . . . . . . . 49
When Should an Airbag
Inflate? . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
What Makes an Airbag Inflate? . . . 52
How Does an Airbag Restrain? . . . 52
What Will You See after an Airbag Inflates? . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Passenger Sensing System . . . . . . . . 53
Servicing the Airbag-Equipped Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Adding Equipment to the Airbag-Equipped Vehicle . . . . . . . . 58
Airbag System Check . . . . . . . . . . . . . . 58
Replacing Airbag System Parts after a Crash . . . . . . . . . . . . . . . . . . . . . . 59
Child Restraints
Older Children . . . . . . . . . . . . . . . . . . . . . 59
Infants and Young Children . . . . . . 60
Child Restraint Systems . . . . . . . . . . . 63
Where to Put the Restraint . . . . . . . 64
Lower Anchors and Tethers forChildren (LATCH System) . . . . . . . 65
Replacing LATCH System Parts After a Crash . . . . . . . . . . . . . . . . . . . . . 72
Securing Child Restraints (With the Seat Belt in the
Rear Seat) . . . . . . . . . . . . . . . . . . . . . . . . 72
Securing Child Restraints (With the Seat Belt in the
Front Seat) . . . . . . . . . . . . . . . . . . . . . . . 74