ECU CADILLAC CT4 2023 Workshop Manual

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Vehicle Care 391
2. Add coolant through thesurge 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 0261.
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 the pressure cap, refill
to the indicated line, replace
the pressure cap, and repeat
steps 6.2 –6.6.
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.
Engine Overheating
The vehicle has an indicator to
warn of the engine
overheating.
If the decision is made not to
lift the hood when this
warning appears, get service
help right away. See Roadside
Assistance Program 0487.
If the decision is made to lift
the hood, make sure the
vehicle is parked on a level
surface.
Then check to see if the
engine cooling fan is running.
If the engine is overheating,
the fan should be running. If it
is not, do not continue to run
the engine. Have the vehicle
serviced.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Vehicle Care 437
Tire Chains
{Warning
If the vehicle has
235/40R18, 235/35R19,
255/35ZR18, or
275/35ZR18 size tires, do
not use tire chains. There is
not enough clearance. Tire
chains used on a vehicle
without the proper amount
of clearance can cause
damage to the brakes,
suspension, or other vehicle
parts. The area damaged by
the tire chains could cause
loss of control and a crash.
Use another type of traction
device only if its
manufacturer recommends
it for the vehicle's tire size
combination and road
conditions. Follow that
manufacturer's instructions.
To avoid vehicle damage,
drive slow and readjust or
remove the traction device if(Continued)
Warning (Continued)
it contacts the vehicle. Do
not spin the wheels.
If traction devices are used,
install them on the rear tires.
Caution
If the vehicle is equipped
with a tire size other than
235/40R18, 235/35R19,
255/35ZR18, or
275/35ZR18, use tire chains
only where legal and only
when necessary. Use low
profile chains that add no
more than 12 mm thickness
to the tire tread and inner
sidewall. Use chains that are
the proper size for the tires.
Install them on the tires of
the rear axle. Don't use
chains on the tires of the
front axle. Tighten them as
tightly as possible with the
ends securely fastened.
Drive slowly and follow the(Continued)
Caution (Continued)
chain manufacturer's
instructions. If the chains
contact the vehicle, stop and
retighten them. If the
contact continues, slow
down until it stops. Driving
too fast or spinning the
wheels with chains on will
damage the vehicle.
If a Tire Goes Flat
It is unusual for a tire to blow
out while driving, especially if
the tires are maintained
properly. If air goes out of a
tire, it is much more likely to
leak out slowly. See Tires
0413 for additional
information. But if there ever
is a blowout, here are a few
tips about what to expect and
what to do:
If a front tire fails, the flat tire
creates a drag that pulls the
vehicle toward that side. Take
your foot off the accelerator
pedal and grip the steering

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
450 Vehicle Care
After starting the disabled
vehicle and removing the
jumper cables, allow it to idle
for several minutes.
Towing the
Vehicle
Transporting a
Disabled Vehicle
(Electronic Shifter)
Caution
Incorrectly transporting a
disabled vehicle may cause
damage to the vehicle. Use
proper tire straps to secure
the vehicle to the flatbed
tow truck. Do not strap or
hook to any frame,
underbody, or suspension
component not specified
below. Do not move vehicles
with drive axle tires on the
ground. Damage is not
covered by the vehicle
warranty.
Caution
The vehicle may be equipped
with an electric parking
brake and/or an electronic
shifter. In the event of a loss
of 12-volt battery power, the
electric parking brake
cannot be released, and the
vehicle cannot be shifted to
N (Neutral). Tire skates or
dollies must be used under
the non-rolling tires to
prevent damage while
loading/unloading the
vehicle. Dragging the vehicle
will cause damage not
covered by the vehicle
warranty.
Caution
The vehicle may be equipped
with a tow eye. Improper use
of the tow eye may cause
damage to the vehicle and is
not covered by the vehicle
warranty. If equipped, use(Continued)
Caution (Continued)
the tow eye to load the
vehicle onto a flatbed tow
truck from a flat road
surface, or to move the
vehicle a very short distance
at a walking pace. The tow
eye is not designed for
off-road recovery. The
vehicle must be in
N (Neutral) with the electric
parking brake released when
using the tow eye.
Contact a professional towing
service if the disabled vehicle
must be transported. GM
recommends a flatbed tow
truck to transport a disabled
vehicle. Use ramps to help
reduce approach angles,
if necessary.
If equipped, a tow eye may be
located near the spare tire or
emergency jack. Do not use
the tow eye to pull the vehicle
from the snow, mud, sand,
or ditch. Tow eye threads may

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
452 Vehicle Care
Install the tow eye into the
socket and turn it until it is
fully tightened. When the tow
eye is removed, reinstall the
cover with the notch in the
original position.
Rear Tow Eye
If equipped, carefully open the
cover by using the small notch
that conceals the rear tow eye
socket. Install the tow eye into
the socket and turn it until it is
fully tightened. When the tow
eye is removed, reinstall the
cover with the notch in the
original position.
Transporting a
Disabled Vehicle
(Mechanical Shifter)
Caution
Incorrectly transporting a
disabled vehicle may cause
damage to the vehicle. Use
proper tire straps to secure
the vehicle to the flatbed
tow truck. Do not strap or
hook to any frame,
underbody, or suspension
component not specified
below. Do not move vehicles
with drive axle tires on the
ground. Damage is not
covered by the vehicle
warranty.
Caution
The vehicle may be equipped
with an electric parking
brake and/or a mechanical
transmission range select
shifter. In the event of a loss(Continued)
Caution (Continued)
of 12-volt battery power, the
electric parking brake
cannot be released, and the
vehicle cannot be shifted to
N (Neutral). Tire skates or
dollies must be used under
the non-rolling tires to
prevent damage while
loading/unloading the
vehicle. Dragging the vehicle
will cause damage not
covered by the vehicle
warranty.
Caution
The vehicle may be equipped
with a tow eye. Improper use
of the tow eye may cause
damage to the vehicle and is
not covered by the vehicle
warranty. If equipped, use
the tow eye to load the
vehicle onto a flatbed tow
truck from a flat road
surface, or to move the(Continued)

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Vehicle Care 465
{Warning
Do not bleach or dye seat
belt webbing. It may severely
weaken the webbing. In a
crash, they might not be
able to provide adequate
protection. Clean and rinse
seat belt webbing only with
mild soap and lukewarm
water. Allow the webbing
to dry.
Floor Mats
{Warning
If a floor mat is the wrong
size or is not properly
installed, it can interfere
with the pedals. Interference
with the pedals can cause
unintended acceleration
and/or increased stopping
distance which can cause a
crash and injury. Make sure
the floor mat does not
interfere with the pedals.Use the following guidelines
for proper floor mat use.
.The original equipment floor
mats are designed for your
vehicle. If the floor mats
need to be replaced, it is
recommended that
GM-certified floor mats are
purchased. Non-GM floor
mats may not fit properly
and may interfere with the
pedals. Always check that
the floor mats do not
interfere with the pedals.
.Do not use a floor mat if the
vehicle is not equipped with
a floor mat retainer on the
driver side floor.
.Use the floor mat with the
correct side up. Do not turn
it over.
.Do not place anything on top
of the driver side floor mat.
.Use only a single floor mat
on the driver side.
.Do not place one floor mat
on top of another.
The floor mats are held in
place by button-type retainers.
Removing and Replacing
the Floor Mats
1. Pull up on the rear of the floor mat to unlock the
retainers and remove.
2. Reinstall by lining up the floor mat retainer openings
over the carpet retainers
and snap into position.
3. Make sure the floor mat is properly secured in place.
Verify the floor mat does
not interfere with the
pedals.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Service and Maintenance 471
Severe Conditions
Requiring More Frequent
Maintenance*
.Public service, military,
or commercial use vehicles
to include the following:
‐Ambulances, police cars,
and emergency rescue
vehicles.
‐ Civilian vehicles such as
light duty pick-up trucks,
SUVs, and passenger cars
that are used in military
applications.
‐ Recovery vehicles such as
tow trucks and flatbed
single vehicle carriers or
any vehicle that is
consistently used in towing
trailers or other loads.
‐ High use commercial
vehicles such as courier
delivery vehicles, private
security patrol vehicles,
or any vehicles that
operate on a 24–hour
basis. ‐
Any vehicle consistently
operated in a high sand or
dust environment such as
those used on oil pipelines
and similar applications.
.Vehicles that are regularly
used for short trips of 6 km
(4 mi) or less.
The oil life indicator will show
you when to change the oil
and filter. Under severe
conditions the indicator may
come on before 12 000 km
(7,500 mi).
* Footnote: Under extreme
driving conditions listed
above, it may be necessary
to replace your spark plugs
at more frequent intervals.
For further assistance in
determining the most
suitable service maintenance
intervals for your vehicle,
please contact your
authorized GM Dealer. Extreme service is for
vehicles mainly driven
off-road in four-wheel drive
or used in farming, mining,
forestry, or snow plowing.Additional Required
Services
—Severe Service
Every 72 000 km (45,000 mi)
.Change automatic
transmission fluid and filter.
.Change transfer case fluid,
if equipped with AWD. Do
not directly power wash the
transfer case and/or front/
rear axle output seals. High
pressure water can
overcome the seals and
contaminate the transfer
case fluid. Contaminated
fluid will decrease the life of
the transfer case and/or
axles and should be
replaced.
.Change rear axle fluid, with
limited slip differential. Do
not directly power wash the
transfer case and/or front/
rear axle output seals. High

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Service and Maintenance 473
Exterior Lights
.Visual inspection
Windshield and Wipers
.Visual inspection
Battery
.Battery visual inspection
.Battery test results
.Battery cables and
connections
Systems, Fluids, and
Visible Leak Inspection
.Engine oil
.Transmission
.Drive axle
.Transfer case
.Engine cooling system
.Power steering, if equipped
.Fuel system
.Windshield washer fluid
Tire Inspection
.Tire pressure, tread depth,
and wear
.Rotation, if applicable
.Alignment check, optional
.Reset tire pressure monitor
.Check tire sealant expiration
date, if equipped
.Check spare tire, if equipped
Brakes
.Check brake system
Visible and Functional
Inspections
.Seat belt components
.Exhaust system
.Accelerator pedal
.Passenger compartment air
filter, if equipped
.Engine air filter
.Hoses
.Belts
.Shocks and struts
.Steering components
.Axle boots or driveshaft and
u-joints
.Compartment lift struts,
if equipped
.Floor mats secured, no
interference with pedals
.Horn
.Ignition lock, if equipped
.Starter switch
.Evaporative control system
Lubricate
.Chassis components
Special Application
Services
.Severe Commercial Use
Vehicles Only: Lubricate
chassis components every
oil change.
.Have underbody flushing
service performed. See
"Underbody Maintenance" in
Exterior Care 0455.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/5/22
Customer Information 483
Customer
Information
Customer Information
Customer SatisfactionProcedure . . . . . . . . . . . . . . . . . 483
Customer Assistance Offices . . . . . . . . . . . . . . . . . . . . . . 485
Customer Assistance for Text Telephone (TTY)
Users . . . . . . . . . . . . . . . . . . . . . . . . 486
Online Account . . . . . . . . . . . . . 486
GM Mobility Reimbursement
Program . . . . . . . . . . . . . . . . . . . . 487
Roadside Assistance Program . . . . . . . . . . . . . . . . . . . . 487
Scheduling Service Appointments . . . . . . . . . . . . 490
Courtesy Transportation Program . . . . . . . . . . . . . . . . . . . . 490
Collision Damage Repair . . . . . . . . . . . . . . . . . . . . . . . . 491
Publication Ordering Information . . . . . . . . . . . . . . . . 494
Radio Frequency Statement . . . . . . . . . . . . . . . . . 494
Reporting Safety Defects
Reporting Safety Defectsto the United States
Government . . . . . . . . . . . . . . . 495
Reporting Safety Defects to the Canadian
Government . . . . . . . . . . . . . . . 495
Reporting Safety Defects to General Motors . . . . . . . 496
Vehicle Data Recording
and Privacy
Vehicle Data Recordingand Privacy . . . . . . . . . . . . . . . . 496
Cybersecurity . . . . . . . . . . . . . . 496
Event Data Recorders . . . 497
OnStar . . . . . . . . . . . . . . . . . . . . . . . . 498
Infotainment System . . . . . 498
Customer
Information
Customer
Satisfaction
Procedure
Your satisfaction and goodwill
are important to your dealer
and to Cadillac. Normally, any
concerns with the sales
transaction or the operation
of the vehicle will be resolved
by your dealer's sales or
service departments.
Sometimes, however, despite
the best intentions of all
concerned, misunderstandings
can occur. If your concern has
not been resolved to your
satisfaction, the following
steps should be taken:
STEP ONE : Discuss your
concern with a member of
dealership management.
Normally, concerns can be
quickly resolved at that level.
If the matter has already been
reviewed with the sales,

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/5/22
488 Customer Information
.Model, year, color, and
license plate number of the
vehicle
.Odometer reading, Vehicle
Identification Number (VIN),
and delivery date of the
vehicle
.Description of the problem
Coverage
Services are provided for the
duration of the vehicle’s
powertrain warranty.
In the U.S., anyone driving the
vehicle is covered. In Canada,
a person driving the vehicle
without permission from the
owner is not covered.
Roadside Assistance is not a
part of the New Vehicle
Limited Warranty. General
Motors North America and
Cadillac reserve the right to
make any changes or
discontinue the Roadside
Assistance program at any
time without notification.General Motors North America
and Cadillac reserve the right
to limit services or payment to
an owner or driver if they
decide the claims are made
too often, or the same type of
claim is made many times.
Cadillac Owner
Privileges™
.Emergency Fuel Delivery:
Delivery of enough fuel for
the vehicle to get to the
nearest service station.
.Lock-Out Service:
Service
to unlock the vehicle if you
are locked out. A remote
unlock may be available if
you have OnStar. For
security reasons, the driver
must present identification
before this service is given.
.Emergency Tow from a
Public Road or Highway:
Tow to the nearest Cadillac
dealer for warranty service,
or if the vehicle was in a
crash and cannot be driven. Assistance is not given when
the vehicle is stuck in the
sand, mud, or snow.
.Flat Tire Change:
Service to
change a flat tire with a
spare tire. The spare tire,
if equipped, must be in good
condition and properly
inflated. It is your
responsibility for the repair
or replacement of the tire if
it is not covered by the
warranty.
.Battery Jump Start: Service
to jump start a dead battery.
.Trip Interruption Benefits
and Service: If your trip is
interrupted due to a
warranty failure, incidental
expenses may be
reimbursed during the
Powertrain warranty period.
Items considered are hotel,
meals, and rental car or a
vehicle being delivered back
to the customer, up to
500 miles.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/5/22
496 Customer Information
Reporting Safety
Defects to General
Motors
In addition to notifying NHTSA
(or Transport Canada) in a
situation like this, notify
General Motors.
In the U.S., call
1-800-458-8006, or write:
Cadillac Customer Assistance
Center
Cadillac Motor Car Division
P.O. Box 33169
Detroit, MI 48232-5169
In Canada, call
1-888-446-2000, or write:
Canadian Cadillac Customer
Care Centre
General Motors of Canada
Company
500 Wentworth Street W
Oshawa, ON L1J 0C5
In Mexico, call 800-466-0805
or 800-212-234-5522.In other Central America and
Caribbean Countries, call
52-555-901-2369.Vehicle Data
Recording and
Privacy
The vehicle has a number of
computers that record
information about the vehicle’s
performance and how it is
driven or used. For example,
the vehicle uses computer
modules to monitor and
control engine and
transmission performance, to
monitor the conditions for
airbag deployment and deploy
them in a crash, and,
if equipped, to provide antilock
braking to help the driver
control the vehicle. These
modules may store data to
help the dealer technician
service the vehicle or to help
GM improve safety or
features. Some modules may
also store data about how thevehicle is operated, such as
rate of fuel consumption or
average speed. These
modules may retain personal
preferences, such as radio
presets, seat positions, and
temperature settings.
Cybersecurity
GM collects information about
the use of your vehicle
including operational and
safety related information. We
collect this information to
provide, evaluate, improve, and
troubleshoot our products and
services and to develop new
products and services. The
protection of vehicle
electronics systems and
customer data from
unauthorized outside
electronic access or control is
important to GM. GM
maintains appropriate security
standards, practices,
guidelines and controls aimed
at defending the vehicle and
the vehicle service ecosystem
against unauthorized