2021 CADILLAC CT4 Owner's Manual

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
328 VEHICLE CARE
To replace the windshield wiper blade:1. Pull the windshield wiper assembly away from the windshield.
2. Lift up on the latch in the middleof the wiper blade where the wiper
arm attaches.
3. With the latch open, pull the wiper blade down toward the windshield
far enough to release it from the
J-hooked end of the wiper arm.
4. Remove the wiper blade.
5. Reverse Steps 1–3 for wiper blade replacement.
Windshield Replacement
HUD System
The windshield is part of the HUD
system. If the windshield needs to be
replaced, be sure to get one that is
designed for HUD or the HUD image
may look out of focus.
Driver Assistance Systems
If the windshield needs to be replaced
and the vehicle is equipped with a
front camera sensor for the Driver
Assistance Systems, a GM
replacement windshield is
recommended. The replacement
windshield must be installed
according to GM specifications for
proper alignment. If it is not, these
systems may not work properly, they
may display messages, or they may
not work at all. See your dealer for
proper windshield replacement.
Acoustic Windshield
The vehicle is equipped with an
acoustic windshield. If the windshield
needs to be replaced be sure to get an acoustic windshield so you will
continue to have the benefits an
acoustic windshield can provide.
Gas Strut(s)
This vehicle is equipped with gas
strut(s) to provide assistance in lifting
and holding open the hood/trunk/
liftgate system in full open position.
{Warning
If the gas struts that hold open the
hood, trunk, and/or liftgate fail, you
or others could be seriously injured.
Take the vehicle to your dealer for
service immediately. Visually
inspect the gas struts for signs of
wear, cracks, or other damage
periodically. Check to make sure the
hood/trunk/liftgate is held open
with enough force. If struts are
failing to hold the hood/trunk/
liftgate, do not operate. Have the
vehicle serviced.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
VEHICLE CARE 329
Caution
Do not apply tape or hang any
objects from gas struts. Also do not
push down or pull on gas struts.
This may cause damage to the
vehicle.
See Maintenance Schedule 0380.
Hood
Trunk
Liftgate
Headlamp Aiming
Front Headlamp Aiming
Headlamp aim has been preset and
should need no further adjustment.
If the vehicle is damaged in a crash,
the headlamp aim may be affected.
If adjustment to the headlamps is
necessary, see your dealer.
Bulb Replacement
For the proper type of replacement
bulbs, or any bulb changing procedure
not listed in this section, contact your
dealer.
Caution
Do not replace incandescent bulbs
with aftermarket LED replacement
bulbs. This can cause damage to
the vehicle electrical system.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
330 VEHICLE CARE
Halogen Bulbs
{Warning
Halogen bulbs have pressurized gas
inside and can burst if you drop or
scratch the bulb. You or others
could be injured. Be sure to read
and follow the instructions on the
bulb package.
High Intensity Discharge
(HID) Lighting
{Warning
The High Intensity Discharge (HID)
lighting system operates at a very
high voltage. If you try to service
any of the system components, you
could be seriously injured. Have
your dealer or a qualified technician
service them.
After an HID headlamp bulb has been
replaced, the beam might be a slightly
different shade than it was originally.
This is normal.
LED Lighting
This vehicle has several LED lamps.
For replacement of any LED lighting
assembly, contact your dealer.
Front Turn Signal Lamps
Uplevel
See your dealer for turn signal
replacement.
Base level
To replace one of these lamps: 1. Open the hood.
2. If your vehicle is equipped with a beauty cover, remove the beauty
cover to get access to the bulb.3. Turn the bulb socketcounterclockwise to remove it from
the headlamp assembly.
4. Unplug the electrical connector from the bulb by releasing the clip
on the connector.
5. Replace the bulb and reverse Steps 1–4 to reinstall.
Electrical System
Electrical System Overload
The vehicle has fuses and circuit
breakers to protect against an
electrical system overload.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
VEHICLE CARE 331
When the electrical load is too heavy
a circuit breaker opens, protecting the
circuit until overcurrent condition is
removed. This greatly reduces the
chance of circuit overload and fire
caused by electrical problems.
Fuses and circuit breakers protect
electrical devices in the vehicle.
Replace a blown or open fuse with a
new one of the identical size and
rating.
If there is a problem on the road and
a fuse needs to be replaced, the
same amperage fuse can be borrowed.
Choose some feature of the vehicle
that is not needed to use and replace
it as soon as possible.
Headlamp Wiring
An electrical overload may cause the
lamps to go on and off, or in some
cases to remain off. Have the
headlamp wiring checked right away if
the lamps go on and off or remain off.
Windshield Wipers
If the wiper motor overheats due to
heavy snow or ice, the windshield
wipers will stop. Wiper function is
available immediately after the wiper
switch is set to off, and back to on.
To protect the wiper motor from
overheating, the wipers may slow
down when the windshield is dry for a
long period of time. If a period of dry
operation, or little moisture, exceeds
10 minutes, the wipers may switch to
intermittent operation, and remain
there. When moisture is again
detected on the windshield, wiper
operation will return to the operator
selected speed.
Although the circuit is protected from
electrical overload, overload due to
heavy snow or ice may cause wiper
linkage damage. Always clear ice and
heavy snow from the windshield
before using the windshield wipers.
If the overload is caused by an
electrical problem and not snow or
ice, be sure to get it fixed.
Fuses and Circuit Breakers
The wiring circuits in the vehicle are
protected from short circuits by a
combination of fuses and circuit
breakers. This greatly reduces the
chance of damage caused by electrical
problems.
{Danger
Fuses and circuit breakers are
marked with their ampere rating.
Do not exceed the
specified amperage rating when
replacing fuses and circuit breakers.
Use of an oversized fuse or circuit
breaker can result in a vehicle fire.
You and others could be seriously
injured or killed.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
332 VEHICLE CARE
{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
0 306 and
General Information 0305.
To check a fuse, look at the
silver-colored band inside the fuse.
If the band is broken or melted,
replace the fuse. Be sure to replace a
bad fuse with a new one of the
identical size and rating.
Fuses of the same amperage can be
temporarily borrowed from another
fuse location, if a fuse goes out.
Replace the fuse as soon as possible.
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-14584335) -
2021 - CRC - 11/23/20
VEHICLE CARE 333
FusesUsage
1 Long range radar front sensor
2 Park/Daytime running lamps
3 Exterior lighting module 4
4 Exterior lighting module 7
5 Headlamp level Fuses
Usage
6 –
7 Electronic brake control module
8 Washer pump
9 –
10 –
11 –
12 Horn Fuses
Usage
13 Front wiper
14 Exterior lighting module 6
15 Exterior lighting module 1
16 Exterior lighting module 5
17 Exterior lighting module 3
18 Aero shutter
19 –
20 –
21 Virtual key system/ Power sounder
module
22 Engine control module
23 Transmission control module/Transmission
reverse lock out
24 Active engine mount
25 –

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
334 VEHICLE CARE
FusesUsage
26 Engine control module
27 Injectors/Ignition 2
28 Charged air cooler
29 Transmission aux oil pump/Transmission
reverse lock out
30 Injectors/Ignition 1
31 Emissions 1
32 Emissions 2
33 Starter solenoid
34 –
35 –
36 Starter pinion
37 AC clutch
38 –
39 –
40 –
41 –
42 Water pump
43 – Fuses
Usage
44 –
Relays Usage
47 –
48 Front wiper speed
49 Front wiper control
51 –
52 Engine control module
53 Starter solenoid
54 Starter pinion
55 –
57 AC clutch
58 –Instrument Panel Fuse
Block
The instrument panel fuse block is in
the end of the driver side of the
instrument panel.
To access the fuses, remove the end
panel by gently prying with a plastic
tool near each clip, beginning at the
point shown.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
VEHICLE CARE 335
To install the end cover, insert the
tabs on the back of the cover into the
slots in the instrument panel at the
points shown. Align the clips with the
slots in the instrument panel, and
press the cover into place.
The vehicle may not be equipped with
all of the fuses and relays shown.
FusesUsage
1 –
2 HVAC blower
3 –
4 –
5 Theft deterrent/ Universal garage door
opener/Overhead
console/Rain sensor Fuses
Usage
6 –
7 Air quality ionizer
8 Heated steering wheel
9 –
10 Electronic steering column lock 1
11 –
12 –