2023 CADILLAC CT4 check engine light

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/10/22
252 Driving and Operating
Warning (Continued)
and could cause pulling to
one side. You could lose
control of the vehicle.
After driving through a large
puddle of water or a car/
vehicle wash, lightly apply
the brake pedal until the
brakes work normally.
Flowing or rushing water
creates strong forces.
Driving through flowing
water could cause the
vehicle to be carried away.
If this happens, you and
other vehicle occupants
could drown. Do not ignore
police warnings and be very
cautious about trying to
drive through flowing water.
Caution
Driving through deep
puddles or standing water
can cause water to come in(Continued)
Caution (Continued)
through the engine air intake
and damage the engine.
If deep puddles or standing
water cannot be avoided,
proceed with caution and do
not exceed 8 km/h (5 mph).
Do not drive through water
that may come close to or
cover the vehicle’s
underbody.
Hydroplaning
Hydroplaning is dangerous.
Water can build up under the
vehicle's tires so they actually
ride on the water. This can
happen if the road is wet
enough and you are going fast
enough. When the vehicle is
hydroplaning, it has little or no
contact with the road.
There is no hard and fast rule
about hydroplaning. The best
advice is to slow down when
the road is wet.
Other Rainy Weather Tips
Besides slowing down, other
wet weather driving tips
include:
.Allow extra following
distance.
.Pass with caution.
.Keep windshield wiping
equipment in good shape.
.Keep the windshield washer
fluid reservoir filled.
.Have good tires with proper
tread depth. See Tires 0413.
.Turn off cruise control.
Hill and Mountain
Roads
Driving on steep hills or
through mountains is different
than driving on flat or rolling
terrain. Tips include:
.Keep the vehicle serviced
and in good shape.
.Check all fluid levels and
brakes, tires, and cooling
system.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/10/22
286 Driving and Operating
.When ARM is deactivated,
the gear number is white.
.If no gear number is
displayed while the shift
lever is in gear, service is
required. All rev matching
will be disabled and the
malfunction indicator lamp
will be on. See Malfunction
Indicator Lamp (Check
Engine Light)0118. The
clutch and manual
transmission will continue to
operate normally.
ARM will also:
.Be active above 28 km/h
(18 mph).
.Match engine speed up to
6100 rpm.
.Not operate when the
accelerator pedal is applied.
.Be disabled when the
coolant temperature is
below 0 °C (32 °F).
Drive Systems
All-Wheel Drive
Vehicles with this feature
always send engine power
to all four wheels. It is fully
automatic, and adjusts itself as
needed for road conditions.
Brakes
Electric Brake Boost
Vehicles equipped with
electric brake boost have
hydraulic brake circuits that
are electronically controlled
when the brake pedal is
applied during normal
operation. The system
performs routine tests and
turns off within a few minutes
after the vehicle is turned off.
Noise may be heard during
this time. If the brake pedal is pressed during the tests or
when the electric brake boost
system is off, a noticeable
change in pedal force and
travel may be felt. This is
normal.
Antilock Brake
System (ABS)
The Antilock Brake System
(ABS) helps prevent a braking
skid and maintain steering
while braking hard.
If there is a problem with ABS,
this warning light stays on.
See Antilock Brake System
(ABS) Warning Light
0121.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/10/22
Driving and Operating 291
Both systems come on
automatically when the vehicle
is started and begins to move.
The systems may be heard or
felt while they are operating
or while performing diagnostic
checks. This is normal and
does not mean there is a
problem with the vehicle.
It is recommended to leave
both systems on for normal
driving conditions, but It may
be necessary to turn TCS off
if the vehicle gets stuck in
sand, mud, ice, or snow. See If
the Vehicle Is Stuck0255 and
“Turning the Systems Off and
On” later in this section.
The indicator light for both
systems is in the instrument
cluster. This light will:
.Flash when TCS is limiting
wheel spin.
.Flash when StabiliTrak/ESC
is activated.
.Turn on and stay on when
either system is not working.
If either system fails to turn on
or to activate, a message may
display in the Driver
Information Center (DIC), and
dcomes on and stays on to
indicate that the system is
inactive and is not assisting
the driver in maintaining
control. The vehicle is safe to
drive, but driving should be
adjusted accordingly.
If
dcomes on and stays on:
1. Stop the vehicle.
2. Turn the engine off and wait 15 seconds.
3. Start the engine.
Drive the vehicle. if
dcomes
on and stays on, the vehicle
may need more time to
diagnose the problem. If the
condition persists, see your
dealer.
Turning the Systems Off
and On
Caution
Do not repeatedly brake or
accelerate heavily when TCS
is off. The vehicle driveline
could be damaged.
To turn off only TCS, press
and release
g. The traction off
light
idisplays in the
instrument cluster. A DIC
message may display.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/10/22
366 Driving and Operating
Trailer Brakes
Loaded trailers over 450 kg
(1,000 lb) must be equipped
with brake systems and with
brakes for each axle. Trailer
braking equipment conforming
to Canadian Standards
Association (CSA) requirement
CAN3-D313, or its equivalent,
is recommended.
State or local regulations may
require trailers to have their
own braking system if the
loaded weight of the trailer
exceeds certain minimums
that can vary from state to
state. Read and follow the
instructions for the trailer
brakes so they are installed,
adjusted, and maintained
properly. Never attempt to tap
into your vehicle's hydraulic
brake system. If you do, both
the vehicle anti-lock brakes
and the trailer brakes may not
function, which could result in
a crash.
Trailer Lamps
Always check all trailer lamps
are working at the beginning
of each trip, and periodically
on longer trips.
Turn Signals When
Towing a Trailer
When properly connected, the
trailer turn signals will
illuminate to indicate the
vehicle is turning, changing
lanes, or stopping. When
towing a trailer, the arrows on
the instrument cluster will
illuminate even if the trailer is
not properly connected or the
bulbs are burned out.
Conversions and
Add-Ons
Add-On Electrical
Equipment
{Warning
The Data Link Connector
(DLC) is used for vehicle
service and Emission
Inspection/Maintenance
testing. See Malfunction
Indicator Lamp (Check
Engine Light)0118. A device
connected to the DLC —
such as an aftermarket fleet
or driver-behavior tracking
device —may interfere with
vehicle systems. This could
affect vehicle operation and
cause a crash. Such devices
may also access information
stored in the vehicle’s
systems.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
368 Vehicle Care
Vehicle Care
General Information
General Information . . . . . . 369
California PerchlorateMaterials
Requirements . . . . . . . . . . . . . 370
Accessories and Modifications . . . . . . . . . . . . . 370
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . 370
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . 371
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . 373
Engine Oil . . . . . . . . . . . . . . . . . . . . 378
Engine Oil Life System . . . 381
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 382
Manual Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 382
Hydraulic Clutch . . . . . . . . . . . 383
Engine Air Filter Life System . . . . . . . . . . . . . . . . . . . . . . 383
Engine Air Cleaner/ Filter . . . . . . . . . . . . . . . . . . . . . . . . . 384
Cooling System . . . . . . . . . . . . 386
Engine Overheating . . . . . . . 391 Washer Fluid . . . . . . . . . . . . . . . . 393
Brakes . . . . . . . . . . . . . . . . . . . . . . . . 393
Brake Pad Life System (If
Equipped) . . . . . . . . . . . . . . . . . . 396
Brake Fluid . . . . . . . . . . . . . . . . . . 398
Battery - North
America . . . . . . . . . . . . . . . . . . . . . 399
All-Wheel Drive . . . . . . . . . . . . 400
Park Brake and P (Park) Mechanism Check . . . . . . . 400
Wiper Blade Replacement . . . . . . . . . . . . . . 401
Windshield Replacement . . . . . . . . . . . . . . 401
Gas Strut(s) . . . . . . . . . . . . . . . . . 402
Headlamp Aiming
Front Headlamp Aiming . . . . . . . . . . . . . . . . . . . . . . . 403
Bulb Replacement
Bulb Replacement . . . . . . . . 403
Halogen Bulbs . . . . . . . . . . . . . . 403
High Intensity Discharge(HID) Lighting . . . . . . . . . . . . . 403
LED Lighting . . . . . . . . . . . . . . . . 403
Front Turn Signal Lamps . . . . . . . . . . . . . . . . . . . . . . . 404
Electrical System
Electrical SystemOverload . . . . . . . . . . . . . . . . . . . 404
Fuses and Circuit Breakers . . . . . . . . . . . . . . . . . . . 406
Engine Compartment
Fuse Block . . . . . . . . . . . . . . . . . 407
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 409
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . 411
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . 413
All-Season Tires . . . . . . . . . . . . 414
Winter Tires . . . . . . . . . . . . . . . . . 414
Run-Flat Tires . . . . . . . . . . . . . . . 415
Self-Sealing Tires . . . . . . . . . . 415
Low-Profile Tires . . . . . . . . . . 416
Summer Tires . . . . . . . . . . . . . . . 416
Tire Sidewall Labeling . . . . 417
Tire Designations . . . . . . . . . . 418
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . . . 419
Tire Pressure . . . . . . . . . . . . . . . 422
Tire Pressure for High-Speed
Operation . . . . . . . . . . . . . . . . . . 423
Tire Pressure Monitor System . . . . . . . . . . . . . . . . . . . . . . 424

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
398 Vehicle Care
Brake Fluid
The brake/clutch master
cylinder reservoir is filled with
GM approved DOT 4 brake
fluid as indicated on the
reservoir cap. See Engine
Compartment Overview0373
for the location of the
reservoir.
Checking Brake Fluid
Place the vehicle in P (Park) or
Neutral with the parking brake
applied if equipped with a
manual transmission. On a
level surface, the brake fluid
level should be between the
minimum and maximum marks
on the brake fluid reservoir. There are only two reasons
why the brake fluid level in the
reservoir may go down:
.Normal brake lining wear.
When new linings are
installed, the fluid level goes
back up.
.A fluid leak in the brake/
clutch hydraulic system.
Have the brake/clutch
hydraulic system fixed. With
a leak, the brakes will not
work well.
Always clean the brake fluid
reservoir cap and the area
around the cap before
removing it.
Do not top off the brake/
clutch fluid. Adding fluid does
not correct a leak. If fluid is
added when the linings are
worn, there will be too much
fluid when new brake linings
are installed. Add or remove
fluid, as necessary, only when
work is done on the brake/
clutch hydraulic system.
{Warning
If too much brake fluid is
added, it can spill on the
engine and burn, if the
engine is hot enough. You or
others could be burned, and
the vehicle could be
damaged. Add brake fluid
only when work is done on
the brake/clutch hydraulic
system.
When the brake/clutch fluid
falls to a low level, the brake
warning light comes on. See
Brake System Warning Light
0 120.
Brake fluid absorbs water over
time which degrades the
effectiveness of the brake
fluid. Replace brake fluid at the
specified intervals to prevent
increased stopping distance.
See Maintenance Schedule
0 469.

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
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.