2023 CADILLAC CT4 check engine

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
400 Vehicle Care
Vehicle Storage
{Warning
Batteries have acid that can
burn you and gas that can
explode. You can be badly
hurt if you are not careful.
See Jump Starting - North
America0447 for tips on
working around a battery
without getting hurt.
Infrequent Usage: Remove the
black, negative (−) cable from
the battery to keep the
battery from running down.
Extended Storage: Remove
the black, negative (−) cable
from the battery or use a
battery trickle charger.
All-Wheel Drive
If the vehicle is equipped with
All-Wheel-Drive (AWD), this is
an additional system that
needs lubrication.
Transfer Case
Under normal driving
conditions, transfer case fluid
does not require maintenance
unless there is a fluid leak or
unusual noise. If required, have
the transfer case serviced by
your dealer.
Park Brake and
P (Park) Mechanism
Check
{Warning
When you are doing this
check, the vehicle could
begin to move. You or
others could be injured and
property could be damaged.
Make sure there is room in
front of the vehicle in case it
begins to roll. Be ready to
apply the regular brake at
once should the vehicle
begin to move. Park on a fairly steep hill, with
the vehicle facing downhill.
Keeping your foot on the
regular brake, set the parking
brake.
.To check the parking brake's
holding ability: With the
engine running and the
transmission in N (Neutral),
slowly remove foot pressure
from the regular brake pedal.
Do this until the vehicle is
held by the parking
brake only.
.Automatic transmission
vehicles only: To check the
P (Park) mechanism's holding
ability: With the engine
running, shift to P (Park).
Then release the parking
brake followed by the
regular brake.
Contact your dealer if service
is required.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Vehicle Care 407
{Warning
Installation or use of fuses
that do not meet GM’s
original fuse specifications is
dangerous. The fuses could
fail, and result in a fire. You
or others could be injured or
killed, and the vehicle could
be damaged.
See Accessories and
Modifications 0370 and
General Information 0369.
To check or replace a blown
fuse, see Electrical System
Overload 0404.
Engine Compartment
Fuse Block
The engine compartment fuse
block is on the driver side of
the engine compartment.
Lift the fuse block cover to
access the fuses. The vehicle may not be
equipped with all of the fuses
and relays shown.
Caution
Spilling liquid on any
electrical component on the
vehicle may damage it.
Always keep the covers on
any electrical component.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
422 Vehicle Care
and the original equipment
tire size and recommended
inflation pressure. See“Tire
and Loading Information
Label” under Vehicle Load
Limits 0255.
Tire Pressure
Tires need the correct
amount of air pressure to
operate effectively.
{Warning
Neither tire underinflation
nor overinflation is good.
Underinflated tires,
or tires that do not have
enough air, can result in:
.Tire overloading and
overheating, which
could lead to a blowout
.Premature or
irregular wear
.Poor handling
(Continued)
Warning (Continued)
.Reduced fuel economy
for internal combustion
engine vehicles
.Reduced range for
electric vehicles
Overinflated tires, or tires
that have too much air,
can result in:
.Unusual wear
.Poor handling
.Rough ride
.Needless damage from
road hazards
The Tire and Loading
Information label on the
vehicle indicates the
original equipment tires
and the correct cold tire
inflation pressures. The
recommended pressure is
the minimum air pressure
needed to support the vehicle's maximum load
carrying capacity. See
Vehicle Load Limits
0255.
How the vehicle is loaded
affects vehicle handling
and ride comfort. Never
load the vehicle with more
weight than it was
designed to carry.
When to Check
Check the pressure of the
tires once a month or more.
How to Check
Use a good quality
pocket-type gauge to
check tire pressure. Proper
tire inflation cannot be
determined by looking at
the tire. Check the tire
inflation pressure when the
tires are cold, meaning the
vehicle has not been driven
for at least three hours or
no more than 1.6 km (1 mi).

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
448 Vehicle Care
2.0L L4 Engine Shown, 3.6LV6 Engine and 2.7L L4 Engine Similar
Connection Points and
Sequence
1. Discharged Battery Positive (+) Terminal
2. Good Battery Positive (+) Terminal
3. Good Battery Negative (−) Terminal
4. Discharged Battery Negative Grounding (−)
Terminal
The jump start positive
terminal (+) and negative post
(−) are on the battery of the
vehicle providing the jump
start.
The jump start remote positive
terminal (+) and the remote
negative grounding terminal (−)
for the discharged battery are
on the passenger side of the
vehicle.
The positive jump start
connection for the discharged
battery is under a cover. Lift
the cover to expose the
terminal.
1. Check the other vehicle. It must have a 12-volt
battery with a negative
ground system.
Caution
If the other vehicle does not
have a 12-volt system with a
negative ground, both
vehicles can be damaged.
Only use a vehicle that has a
(Continued)
Caution (Continued)
12-volt system with a
negative ground for jump
starting.
2. Position the two vehicles so that they are not
touching.
3. Set the parking brake firmly and put the shift
lever in P (Park) with an
automatic transmission,
or Neutral with a manual
transmission.
Caution
If any accessories are left on
or plugged in during the
jump starting procedure,
they could be damaged. The
repairs would not be
covered by the vehicle
warranty. Whenever
possible, turn off or unplug
all accessories on either
vehicle when jump starting.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
458 Vehicle Care
Do not use any of the
following items on lamp
covers:
.Abrasive or caustic agents.
.Washer fluids and other
cleaning agents in higher
concentrations than
suggested by the
manufacturer.
.Solvents, alcohols, fuels,
or other harsh cleaners.
.Ice scrapers or other hard
items.
.Aftermarket appearance
caps or covers while the
lamps are illuminated, due to
excessive heat generated.
Caution
Failure to clean lamps
properly can cause damage
to the lamp cover that would
not be covered by the
vehicle warranty.
Caution
Using wax on low gloss black
finish stripes can increase
the gloss level and create a
non-uniform finish. Clean low
gloss stripes with soap and
water only.
Air Intakes
Clear debris from the air
intakes between the hood and
windshield when washing the
vehicle.
Shutter System
The vehicle may have a
shutter system designed to
help improve fuel economy.
Always keep the shutter
system clear of debris, snow
and ice. If the check engine
light is activated, please check
to see if the shutter system is
clear of debris, snow or ice.
Windshield and Wiper
Blades
Clean the outside of the
windshield with glass cleaner.
Clean rubber wiper blades
using a lint-free cloth or paper
towel soaked with windshield
washer fluid or a mild
detergent. Wash the
windshield thoroughly when
cleaning the blades. Bugs,
road grime, sap, and a buildup
of vehicle wash/wax
treatments may cause wiper
streaking.
Replace the wiper blades if
they are worn or damaged.
Damage can be caused by

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
468 Service and Maintenance
Caution (Continued)
on the vehicle. The use of
flushes, solvents, cleaners,
or lubricants that are not
approved by GM could
damage the vehicle,
requiring expensive repairs
that are not covered by the
vehicle warranty.
The Tire Rotation and
Required Services are the
responsibility of the vehicle
owner. It is recommended to
have your dealer perform
these services every
12 000 km/7,500 mi. Proper
vehicle maintenance helps to
keep the vehicle in good
working condition, improves
fuel economy, and reduces
vehicle emissions.
Because of the way people
use vehicles, maintenance
needs vary. There may need to
be more frequent checks and
services. The Additional
Required Services - Normal
are for vehicles that:
.Carry passengers and cargo
within recommended limits
on the Tire and Loading
Information label. See
Vehicle Load Limits 0255.
.Are driven on reasonable
road surfaces within legal
driving limits.
.Use the recommended fuel.
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.
Refer to the information in the
Maintenance Schedule
Additional Required Services -
Normal Service.
The Additional Required
Services - Severe are for
vehicles that are:
.Mainly driven in heavy city
traffic in hot weather.
.Mainly driven in hilly or
mountainous terrain.
.Frequently towing a trailer.
.Used for high speed or
competitive driving.
.Used for taxi, police,
or delivery service.
Refer to the information in the
Maintenance Schedule
Additional Required Services -
Severe Service.
{Warning
Performing maintenance
work can be dangerous and
can cause serious injury.
Perform maintenance work
only if the required
information, proper tools,
and equipment are available.
If they are not, see your
dealer to have a trained
technician do the work. See
Doing Your Own Service
Work 0370.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Service and Maintenance 469
Maintenance
Schedule
Tire Rotation and
Required Services Every
12 000 km (7,500 mi)
Tires are rotated to achieve a
more uniform wear for all tires.
The first rotation is the most
important.
Anytime unusual wear is
noticed, rotate the tires as
soon as possible, check for
proper tire inflation pressure,
and check for damaged tires
or wheels. If the unusual wear
continues after the rotation,
check the wheel alignment.
See When It Is Time for New
Tires0431 and
Wheel Replacement 0436.
.Perform Multi-Point Vehicle
Inspection. See Multi-Point
Vehicle Inspection (MPVI)
0472.
.Lubricate body components.
See Exterior Care 0455.
Additional Required
Services —Normal
Service
Every 12 000 km (7,500 mi)
.Check engine oil level and oil
life percentage. If needed,
change engine oil and filter,
and reset oil life system. Or
when the CHANGE ENGINE
OIL SOON message displays,
have the engine oil and filter
changed within the next
1 000 km/600 mi. If driven
under the best conditions,
the engine oil life system
may not indicate the need
for vehicle service for up to
a year. The engine oil and
filter must be changed at
least once a year and the oil
life system must be reset.
Your trained dealer
technician can perform this
work. If the engine oil life
system is reset accidentally,
service the vehicle within
5 000 km/3,000 mi since the
last service. Reset the oil life system when the oil is
changed. See Engine Oil Life
System
0381.
.When the REPLACE AT
NEXT OIL CHANGE
message displays, the engine
air filter should be replaced
at the next engine oil
change. When the REPLACE
ENGINE AIR FILTER SOON
message displays, the engine
air filter should be replaced
at the earliest convenience.
Reset the engine air filter life
system after the engine air
filter is replaced. See Engine
Air Filter Life System 0383.
Every 36 000 km (22,500 mi)
.Passenger compartment air
filter replacement (or every
24 months, whichever
occurs first). More frequent
replacement may be needed
if the vehicle is driven in
areas with heavy traffic,
poor air quality, areas with
high dust levels or are
sensitive to environmental
allergens. Filter replacement

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
472 Service and Maintenance
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 front axle 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.
Every 120 000 km
(75,000 mi)
.Change rear axle fluid,
without limited slip
differential. 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.
Owner Checks and
Services
Every Five Years
.Replace brake fluid every
five years. See Brake Fluid
0
398.
Every Seven Years
.Replace Air Conditioning
Desiccant every seven years.
The air conditioning system
requires maintenance every
seven years. This service
requires replacement of the
desiccant to help the
longevity and efficient
operation of the air
conditioning system. This
service can be complex. See
your dealer.
Multi-Point Vehicle
Inspection (MPVI)
A Multi Point Vehicle
Inspection (MPVI) completed
by a GM dealer technician is a
maintenance assessment of
your vehicle. The benefit of
the MPVI is to identify and
inform the customer of service
items that require immediate
attention and those that may
require attention in the future.
The technician will perform the
following checks on your
vehicle. For a complete list of
checks, inspections, and
services, see your dealer.
Some items may not apply to
your vehicle and/or region.
Diagnostics
.OnStar active, if equipped
.Service history/recall check
Engine Oil and Filter
.Engine oil
.Oil life monitor
‐ Reset oil life monitor