ECU CADILLAC CT4 2023 Service Manual

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
208 Infotainment System
Wi-Fi Hotspot
Allows adjustment of different
Wi-Fi features.
Privacy
Allows adjustment of the
infotainment privacy settings.
Display
Allows adjustment of the
infotainment display.
Sounds
Allows adjustment of the
infotainment system sounds.
Voice
Allows adjustment of the
infotainment voice recognition
features.
Favorites
Allows adjustment of the
infotainment favorite settings.
Updates
If equipped, the vehicle can
download and install select
software updates over a
wireless connection. The
system will prompt for certainupdates to be downloaded
and installed. There is also an
option to check for updates
manually.
To manually check for
updates, touch Settings on
the Home Page and select the
System tab. Go to the Vehicle
Software section and touch
Updates. Follow the on-screen
prompts. The steps to check
for, download, and install
updates may vary by vehicle.
The vehicle can be used
normally during the software
download. Once the download
is complete, there may be a
prompt to accept the
installation of the update upon
the next ignition cycle or the
next time the vehicle is shifted
into P (Park). For most
updates, the vehicle will be
disabled and cannot be driven
during the installation. The
system will deliver messages
indicating success or error
during and after the download
and installation processes.
Downloading Over-the-Air
vehicle software updates
requires Internet connectivity,
which can be accessed
through the vehicle’s built-in
4G LTE connection,
if equipped and active.
If required, data plans are
provided by a third party.
Optionally, a secure Wi-Fi
hotspot such as a compatible
mobile device hotspot, home
hotspot, or public hotspot can
be used. Applicable data rates
may apply.
To connect the infotainment
system to a secured mobile
device hotspot, home hotspot,
or public hotspot, touch
Settings on the Home Page,
select the System tab,
followed by Wi-Fi Networks.
Select the appropriate Wi-Fi
network, and follow the
on-screen prompts. Download
speeds may vary.
On most compatible mobile
devices, activation of the Wi-Fi
hotspot is in the Settings

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Infotainment System 211
The menu may contain the
following:
Name
Touch to edit your user name
that will be displayed in the
vehicle.
Vehicle Account Information
Touch to view the vehicle
account information and to
change the account password.
An“unverified user account”
pop-up will display until the
account information
verification process has been
completed on the Internet.
Check your registered e-mail
account for an activation
e-mail to complete the
verification process.
Profile Picture
Touch to choose or change
your profile picture.
Profile Identifiers
Touch to have the vehicle
recognize the identifier you
choose. Touch Vehicle Key 1 and/or
Vehicle Key 2.
If the remote key is lost or
stolen, see your dealer.
Security
Touch to have your profile
secured with a PIN.
Touch No or Yes.
Vehicle Name
Touch to edit your
vehicle name.
Vehicle Account
Touch to view the vehicle
account information and to
change the account password.
Delete Profile
Touch to remove the profile
from the vehicle.
Touch Remove or Cancel.
Teen Driver
If equipped, this allows
multiple keys to be registered
for beginner drivers to
encourage safe driving habits.When the vehicle is started
with a Teen Driver key, it will
automatically activate certain
safety systems, allow setting
of some features, and limit the
use of others. The Report
Card will record vehicle data
about driving behavior that
can be viewed later. When the
vehicle is started with a
registered key, the Driver
Information Center (DIC)
displays a message that Teen
Driver is active.
To access:
1. Touch Settings on the Home Page, then touch
Vehicle, and then Teen
Driver.
2. Create a Personal Identification Number (PIN)
by choosing a four-digit
PIN. Re-enter the PIN to
confirm. To change the
PIN, touch Change PIN.
The PIN is required to:
.Set up/Add or remove keys.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
214 Infotainment System
When Teen Driver is Active:
.If equipped, the radio will
mute when the driver seat
belt, and in some vehicles
the front passenger seat
belt, is not buckled. The
audio from any device paired
to the vehicle will also be
muted.
.An object placed on the
front passenger seat, such
as a briefcase, handbag,
grocery bag, laptop, or other
electronic device, could
cause the passenger
sensing system to falsely
sense an unbuckled front
passenger and mute the
radio. If this happens,
remove the object from the
seat. See Passenger
Sensing System066.
.Some safety systems, such
as Automatic Emergency
Braking, if equipped, cannot
be turned off.
.The gap setting for Adaptive
Cruise Control and alert
timing for Forward Collision
Alert, if equipped, cannot be
changed.
.When trying to change a
safety feature that is not
configurable in Teen Driver,
the feature may be grayed
out or removed from the
infotainment menu, or the
DIC will display a message
indicating that Teen Driver is
active and the action is not
available.
.Super Cruise, if equipped, is
not available.
.Enhanced Low Fuel Warning
(if equipped) –When the
vehicle is low on fuel, the low
fuel light on the instrument
cluster flashes and the DIC
low fuel warning cannot be
dismissed.
.Do not tow a trailer if
equipped with Automatic
Emergency Braking. Report Card
The vehicle owner must
secure the driver’s consent to
record certain vehicle data
when the vehicle is driven with
a registered Teen Driver key.
There is one Report Card per
vehicle. Data is only recorded
when a registered Teen Driver
key is used to operate the
vehicle.
The Report Card data is
collected from the time Teen
Driver is activated or the last
time the Report Card was
reset. The following items may
be recorded:
.Distance Driven
–the total
distance driven.
.Maximum Speed –the
maximum vehicle speed
detected.
.Overspeed Warnings –the
number of times the speed
warning setting was
exceeded.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/10/22
Driving and Operating 239
Warning (Continued)
perform these procedures
properly could cause
malfunction, potentially
resulting in death, personal
injury, or damage to the
vehicle or property. Do not
attempt to perform these
adjustments or procedures
unless properly qualified.
{Warning
Prior to each track event
and again before returning
to public roads, tighten the
wheel nuts with a torque
wrench to the proper torque
specification. Wheel nuts
that are improperly or
incorrectly tightened can
cause the wheels to become
loose or come off, resulting
in a crash. See Capacities
and Specifications0480 for
wheel nut torque
specifications.
Caution
Low oil levels can damage
the engine. If using the
vehicle for competitive
driving, the engine may use
more oil than it would with
normal use. Check the oil
level often during
competitive driving.
Competitive Driving Mode can
be selected. See Driver Mode
Control 0292.
Seat Belts
Lap-Shoulder Belt
If equipped, the driver seat
belt has an Automatic Locking
Retractor (ALR). This feature
is useful in performance
driving scenarios where the
driver wants to be held in the
seat more tightly to take
advantage of the aggressive
bolstering of the seat.
1. Move the seat 8-10 cm (3-4 in) rearward from the
normal driving position. 2. Pull the driver shoulder
belt out as far as it will go,
until it stops, to set the
lock. While holding the
shoulder belt in this
position, buckle the belt.
When the shoulder belt is
released, the retractor will
make a ratchet sound
when it retracts. When the
retractor lock is set, the
belt can be tightened but
not pulled out of the
retractor.
3. Adjust the belt, and then move the seat forward
8-10 cm (3-4 in) to the
desired driving position.
This will secure the belt.
The belt fit should be tight,
but not uncomfortable.
To unlatch the belt, press
the button on the buckle.
The belt should return to
its stowed position.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/10/22
Driving and Operating 241
the pads, or any other work.
The battery must be
disconnected to prevent the
brake master cylinder from
pressurizing the hydraulic
system during its automated
self diagnostic tests that may
occur when a door is opened
or the remote key is present.
{Warning
To avoid personal injury and/
or vehicle damage, always
disconnect the battery
before performing service
work on the hydraulic brake
system. Bleeding the brake
system with the battery
connected can lead to
excessive pressurization of
the system during automatic
diagnostic tests or diagnosis
of a leak or air in the braking
system. A Diagnostic
Trouble Code (DTC) may set
and vehicle speed may be
limited.Brake Cooling (V-Series
Blackwing)
Prior to any track event, high
speed driving event,
or competitive driving,
complete the following:
1. Ensure all the brake cooling parts are correctly
secured and installed.
2. Inspect and replace any deflectors that have
damage.
3. Inspect for blockage in the front brake cooling duct
prior to every event.
If improved brake cooling is
desired, install the ball joint
protector front shields,
remove both upper and lower
rear rotor shields, and install
the rear lower control arm
cooling deflectors, per the
instructions included with the
brake cooling kit. These parts
are for track use only. After
track events reinstall original
front and rear rotor shields,
and remove rear lower control
arm cooling deflectors.Right Side Front Shown, Left Side Front Similar
1. Front Lower Control Arm Deflector

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/10/22
244 Driving and Operating
Caution
The new vehicle break-in
period should be completed
before performing the brake
burnish procedure,
otherwise damage may
occur to the powertrain/
engine. See New Vehicle
Break-In0259.
Caution
Brake fade will occur during
this track burnish procedure
and can cause brake pedal
travel and force to increase.
This could extend stopping
distance until the brakes are
fully burnished.
When this procedure is
performed as instructed, it will
not damage the brakes. The
brake pads will smoke and
produce an odor. The braking
force and pedal travel may
increase. After the procedure,
the brake pads may appear
white at the rotor contact. Perform this procedure only
on dry pavement, in a safe
manner, and in compliance
with all local and state
ordinances/laws regarding
motor vehicle operation.
Street High Performance
Brake Burnishing Procedure
This section is for the V-Series
Blackwing with J57 carbon
ceramic brake rotors only.
This procedure should only be
run on a track or other
non-public area, and only on
dry pavement.
Caution
Brake fade will occur during
this track burnish procedure
and can cause brake pedal
travel and force to increase.
This could extend stopping
distance until the brakes are
fully burnished.
1. From a stop, accelerate as
rapidly as possible without
activating traction control
to a speed of 100 km/h
(60 mph).
2. Using the G-Force Gauge in the HUD display, use
enough pedal force to
completely stop the vehicle
in four to five seconds.
(~0.7g Decel level to stop
the vehicle in a straight
line). If ABS activates,
braking is too hard.
3. Repeat the first two steps 20 consecutive times, this
should take about
five minutes.
4. After completing the 20 stops, cool the brakes by
driving for 8 km (5 mi) at
100 km/h (60 mph).
Alternative Closed Course
Brake Burnishing Procedure
This brake burnish procedure
should only be run on vehicles
with a factory equipped brake
system.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/10/22
Driving and Operating 259
Vehicle Weight Rating
(GVWR). The GVWR
includes the weight of the
vehicle, all occupants, fuel,
and cargo.
{Warning
Things inside the vehicle
can strike and injure
people in a sudden stop
or turn, or in a crash.
.Put things in the cargo
area of the vehicle. In
the cargo area, put
them as far forward as
possible. Try to spread
the weight evenly.
.Never stack heavier
things, like suitcases,
inside the vehicle so
that some of them are
above the tops of the
seats.
(Continued)
Warning (Continued)
.Do not leave an
unsecured child
restraint in the vehicle.
.Secure loose items in
the vehicle.
.Do not leave a seat
folded down unless
needed.
Starting and
Operating
New Vehicle Break-In
Caution
Follow these recommended
guidelines during the first
2 414 km (1,500 mi) of driving
this vehicle. Parts have a
break-in period and
performance will be better in
the long run.
.Avoid full throttle starts
and abrupt stops. (Continued)
Caution (Continued)
.Do not exceed 4000
engine rpm.
.Avoid driving at any one
constant speed, fast
or slow.
.Do not drive above
129 km/h (80 mph).
.Avoid downshifting to
brake or slow the vehicle
when the engine speed
will exceed 4000 rpm.
.Do not let the engine
labor. Never lug the engine
in high gear at low speeds.
With a manual
transmission, shift to the
next lower gear. This rule
applies at all times, not
just during the break-in
period.
.Do not participate in
racing events, sport
driving schools, or similar
activities during this
break-in period.
(Continued)

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/10/22
Driving and Operating 267
Warning (Continued)
cause a fire, property
damage, electric shock,
and injury.
.Do not operate the vehicle
with the heater cord
permanently attached to
the vehicle. Possible
heater cord and
thermostat damage could
occur.
.While in use, do not let the
heater cord touch vehicle
parts or sharp edges.
Never close the hood on
the heater cord.
.Before starting the
vehicle, unplug the cord,
reattach the cover to the
plug, and securely fasten
the cord. Keep the cord
away from any moving
parts.
5. Before starting the engine, be sure to unplug and
store the cord as it was
before to keep it away from moving engine parts.
If you do not, it could be
damaged.
Contact your dealer for
information on how long to
use the heater in your
particular area.
Retained Accessory
Power (RAP)
When the vehicle is turned
from on to off, the following
features (if equipped) will
continue to function for up to
10 minutes, or until the driver
door is opened. These
features will also work when
the vehicle is on or in
accessory mode:
.Infotainment System
.Power Windows (during RAP
this functionality will be lost
when any door is opened)
.Sunroof (during RAP this
functionality will be lost
when any door is opened)
.Auxiliary Power Outlet
.Audio System
.OnStar System
Shifting Into Park
(Mechanical Shifter)
1. Hold the brake pedal down and set the parking brake.
See Electric Parking Brake
0287.
2. Move the shift lever into P (Park) by holding in the
button on the shift lever
and pushing the shift lever
all the way toward the
front of the vehicle.
3. Turn the ignition off.
Leaving the Vehicle with
the Engine Running
{Warning
It can be dangerous to leave
the vehicle with the engine
running. It could overheat
and catch fire. (Continued)

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/10/22
360 Driving and Operating
If equipped, the following
driver assistance features
should be turned to alert or
off when towing a trailer:
.Automatic Emergency
Braking (AEB)
.Intelligent Brake Assist (IBA)
.Front Pedestrian
Braking (FPB)
If equipped with Lane Change
Alert (LCA), the LCA detection
zones that extend back from
the side of the vehicle do not
move further back when a
trailer is towed. Use caution
while changing lanes when
towing a trailer.
If equipped with Rear Cross
Traffic Alert (RCTA), use
caution while backing up when
towing a trailer, as the RCTA
detection zones that extend
out from the back of the
vehicle do not move further
back when a trailer is towed.
{Warning
To prevent serious injury or
death from carbon monoxide
(CO), when towing a trailer:
.Do not drive with the
liftgate, trunk/hatch,
or rear-most
window open.
.Fully open the air outlets
on or under the
instrument panel.
.Adjust the climate control
system to a setting that
brings in only outside air.
See “Climate Control
Systems” in the Index.
For more information about
carbon monoxide, see
Engine Exhaust 0271.
Towing a trailer requires
experience. The combination
of the vehicle and trailer is
longer and not as responsive
as the vehicle itself. Become
familiar with handling and braking by driving on a level
road surface before driving on
public roads.
The trailer structure, the tires,
and the brakes must be all be
rated to carry the intended
cargo. Inadequate trailer
equipment can cause the
combination to operate in an
unexpected or unsafe manner.
Before driving, inspect all
trailer hitch parts and
attachments, safety chains,
electrical connectors, lamps,
tires, and mirrors. See Towing
Equipment
0365. If the trailer
has electric brakes, start the
combination moving and then
manually apply the trailer
brake controller to check the
trailer brakes work. During the
trip, occasionally check that
the cargo and trailer are
secure and that the lamps and
any trailer brakes are working.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
390 Vehicle Care
To use this feature:
1. With a cold system, addcoolant 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 0261.
3.3.Turn off the air conditioning. 3.4.Set the parking brake.
3.5.At the same time, press
the accelerator 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.