2021 CADILLAC XT4 lock

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14584367) - 2021 - CRC - 10/14/20
VEHICLE CARE 293
How to Add Coolant to the
Surge Tank
{Warning
Spilling coolant on hot engine parts
can burn you. Coolant contains
ethylene glycol and it will burn if
the engine parts are hot enough.
{Warning
Steam and scalding liquids from a
hot cooling system are under
pressure. Turning the pressure cap,
even a little, can cause them to
come out at high speed and you
could be burned. Never turn the cap
when the cooling system, including
the pressure cap, is hot. Wait for
the cooling system and pressure
cap to cool.
Caution
Failure to follow the specific
coolant fill procedure could cause
the engine to overheat and could(Continued)
Caution (Continued)
cause system damage. If coolant is
not visible in the surge tank,
contact your dealer.
The coolant surge tank pressure cap
can be removed when the cooling
system, including the surge tank
pressure cap and upper radiator hose,
is no longer hot.
1. Turn the pressure cap slowly counterclockwise. If a hiss is heard,
wait for that to stop. A hiss means
there is still some pressure left.
2. Keep turning the pressure cap slowly and remove it.
3. If topping off the level in thecoolant surge tank, add the proper
mixture until the level reaches the
mark on the front of the tank and
replace the cap. Operate the
vehicle. Repeat steps 1–3, as
necessary.
If filling the system (such as after
servicing), follow the Automatic
Coolant Service Fill Instructions.
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.

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14584367) - 2021 - CRC - 10/14/20
302 VEHICLE CARE
Back-Up Lamps
To replace one of these bulbs:
1. Remove the fasteners to removethe trailer hitch cover. 2. Access the lamp through the
opening in the underbody.
3. Disconnect the electrical connector from the bulb assembly.
4. Turn the bulb socketcounterclockwise and pull the bulb
straight out of the socket.
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. When the current electrical load is too
heavy, the circuit breaker opens and
closes, protecting the circuit until the
current load returns to normal or the
problem is fixed. This greatly reduces
the chance of circuit overload and fire
caused by electrical problems.
Fuses and circuit breakers protect
power devices in the vehicle.
Replace a bad 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.

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14584367) - 2021 - CRC - 10/14/20
VEHICLE CARE 303
Windshield Wipers
If the wiper motor overheats due to
heavy snow or ice, the windshield
wipers will stop until the motor cools
and will then restart.
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(CONTINUED)
Danger (Continued)
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.
{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
0 283 and
General Information 0282. 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 underhood fuse block is in the
engine compartment, on the driver
side of the vehicle.

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14584367) - 2021 - CRC - 10/14/20
304 VEHICLE CARE
Caution
Do not pull the engine
compartment fuse block lever, since
it is intended only for service
purposes. If pulled, vehicle
malfunction may occur.
Caution
Spilling liquid on any electrical
component on the vehicle may
damage it. Always keep the covers
on any electrical component.
To remove the fuse block cover, press
the clips on the cover and lift it
straight up.
The vehicle may not be equipped with
all of the fuses, relays, and features
shown.
Fuses Usage
3 Electronic brake control module Fuses
Usage
5 Trailer brake
6 Rear closure

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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VEHICLE CARE 305
FusesUsage
7 Trailer stop/Turn LH
8 Memory seat module
9 Pedestrian friendly alert function
10 Semi-active damping system
11 DC DC Battery 1/2
12 Rear defogger
13 Heated mirror
14 –
15 Passive entry passive start
16 Front wiper
17 Passenger power seat
18 Power liftgate module
19 Driver power seat
21 Sunroof
22 Rear wiper
23 Trailer interface module 2 Fuses
Usage
26 Transmission control module/Ignition
27 Instrument panel body/ Ignition
28 Rear wiper
29 Trailer ignition
30 Malfunction indicator lamp start/stop Trailer
interface module ignition
32 Rear drive control module 1
33 –
34 Handsfree/Window switch
35 Diesel exhaust fuel heater
36 Fuel module
39 Massage
40 Steering column lock
41 –
43 Heated steering wheel Fuses
Usage
44 Seat ventilation/Front heated seat
46 Engine control module/ Ignition
48 Rear drive control module 2
49 Heating ventilation/Air conditioning blower
motor
50 –
51 –
54 –
55 –
56 Starter motor
57 –
58 –
59 High-beam headlamps left/right
60 Trailer interface module 1
61 –
62 –

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14584367) - 2021 - CRC - 10/14/20
306 VEHICLE CARE
FusesUsage
63 –
65 Air conditioning control
67 –
68 –
69 –
70 Trailer park lamp
72 Starter pinion
75 Engine control module main
76 Powertrain off engine
78 Horn
79 Washer pump
81 Transmission control module/Engine control
module/Cooling pump
82 Nitrogen oxide sensor
83 Ignition coil
84 Powertrain on engine
85 Shunt
86 –
87 Diesel fuel heater 1 Fuses
Usage
88 Aeroshutter
89 Selective catalytic reduction module
92 Trailer stop/Turn right
93 Automatic headlamp leveling/Canister vent
solenoid
95 Smart sensors
96 Diesel fuel heater 2
99 –
Relays Usage
4 –
20 Rear defogger
25 Front wiper control
31 Run/Crank
37 Front wiper speed
42 –
64 Starter motor
66 Powertrain
71 Trailer park lamp Relays
Usage
73 Air conditioning control
80 Starter pinion
90 Powertrain sensor
94 Diesel exhaust fuel heater
98 Diesel fuel heater
Instrument Panel Fuse
Block
The instrument panel fuse block is on
the driver side of the instrument
panel, between the steering wheel and

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14584367) - 2021 - CRC - 10/14/20
308 VEHICLE CARE
FusesUsage
F14 –
F15 Transmission control module (Stop/Start)
F16 Amplifier
F17 –
F18 Video processing module
F19 Power steering column
F20 Body control module 6
F21 Body control module 4
F22 Body control module 7
F23 Electric steering column lock
F24 Airbag
F25 Data link connector
F26 –
F27 –
F28 –
F29 Body control module 8
F30 Overhead console
F31 Steering wheel control Fuses
Usage
F32 –
F33 Heating ventilation/Air conditioning
F34 Central gateway module
F35 Heated switch
F36 Charger
F37 Auxiliary power outlet–front
F38 OnStar
F39 Display
F40 Obstacle detection
F41 Body control module 1 (Stop/Start)
F42 Radio
F43 Auxiliary power outlet–console (circuit
breaker)
F44 Auxiliary power outlet–console Relay
Usage
K1 –
K2 Retained accessory
power
K3 Content theft
K4 –
K5 –
Wheels and Tires
Tires
Every new GM vehicle has
high-quality tires made by a
leading tire manufacturer. See the
warranty manual for information
regarding the tire warranty and
where to get service. For
additional information refer to the
tire manufacturer.
{Warning
.Poorly maintained and
improperly used tires are
dangerous.
(Continued)

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14584367) - 2021 - CRC - 10/14/20
326 VEHICLE CARE
Warning (Continued)
and cause a crash. Use only
radial-ply tires with the wheels
on the vehicle.
Winter tires with the same speed
rating as the original equipment
tires may not be available for H, V,
W, Y and ZR speed rated tires.
Never exceed the winter tires’
maximum speed capability when
using winter tires with a lower
speed rating.
If the vehicle tires must be
replaced with a tire that does not
have a TPC Spec number, make
sure they are the same size, load
range, speed rating, and
construction (radial) as the
original tires.
The Tire and Loading Information
label indicates the original
equipment tires on the vehicle.
See Vehicle Load Limits 0215.Different Size Tires and
Wheels
If wheels or tires are installed that are
a different size than the original
equipment wheels and tires, vehicle
performance, including its braking,
ride and handling characteristics,
stability, and resistance to rollover
may be affected. If the vehicle has
electronic systems such as antilock
brakes, rollover airbags, traction
control, electronic stability control,
or All-Wheel Drive, the performance
of these systems can also be affected.
{Warning
If different sized wheels are used,
there may not be an acceptable
level of performance and safety if
tires not recommended for those
wheels are selected. This increases
the chance of a crash and serious
injury. Only use GM specific wheel
and tire systems developed for the
vehicle, and have them properly
installed by a GM certified
technician. See
Buying New Tires 0325 and
Accessories and Modifications 0283.
Uniform Tire Quality
Grading
The following information relates
to the system developed by the
United States National Highway
Traffic Safety Administration
(NHTSA), which grades tires by
treadwear, traction, and
temperature performance. This
applies only to vehicles sold in the
United States. The grades are
molded on the sidewalls of most
passenger car tires. The Uniform
Tire Quality Grading (UTQG)
system does not apply to deep
tread, winter tires, compact spare
tires, tires with nominal rim
diameters of 10 to 12 inches
(25 to 30 cm), or to some
limited-production tires.
While the tires available on
General Motors passenger cars
and light trucks may vary with
respect to these grades, they must