ECU CADILLAC XT4 2024 Service Manual

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
17180837) - 2024 - CRC - 2/28/23
Driving and Operating 173
The Certification/Tire label may also
show the maximum weights for the
front and rear axles, called the Gross
Axle Weight Rating (GAWR). To find out
the actual loads on the front and rear
axles, weigh the vehicle at a weigh
station. Your dealer can help with this.
Be sure to spread the load equally on
both sides of the centerline.Caution
Overloading the vehicle may cause
damage. Repairs would not be covered by
the vehicle warranty. Do not overload the
vehicle.
{Warning
Things inside the vehicle can strike
and injure people in a sudden stop or
turn, or in a crash.
.Put things in the cargo area of the
vehicle. In the cargo area, put
them as far forward as possible.
Try to spread the weight evenly.
(Continued)
Warning (Continued)
.Never stack heavier things, like
suitcases, inside the vehicle so
that some of them are above the
tops of the seats.
.Do not leave an unsecured child
restraint in the vehicle.
.Secure loose items in the vehicle.
.Do not leave a seat folded down
unless needed.
Starting and Operating
New Vehicle Break-In
Caution
The vehicle does not need an elaborate
break-in. But it will perform better in the
long run if you follow these guidelines:
.Do not drive at any one constant
speed, fast or slow, for the first
800 km (500 mi). Do not make
full-throttle starts. Avoid downshifting
to brake or slow the vehicle.
(Continued)
Caution (Continued)
.Avoid making hard stops for the first
300 km (200 mi) or so. During this
time the new brake linings are not yet
broken in. Hard stops with new linings
can mean premature wear and earlier
replacement. Follow this breaking-in
guideline every time you get new
brake linings.
.Do not tow a trailer during break-in.
See Trailer Towing 0253 for the trailer
towing capabilities of the vehicle and
more information.
Following break-in, engine speed and load
can be gradually increased.
On new vehicles, the various mechanical and
electrical systems experience a “break-in”
period during the first 6 400 km (4,000 mi)
of routine driving. As the vehicle is driven,
the mechanical systems adjust to provide
optimal fuel economy and transmission shift
performance.
Electrical systems will adapt and calibrate
during the break-in period. A one-time
occurrence of clicks and similar vehicle
noises is normal during this process.

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
17180837) - 2024 - CRC - 2/28/23
178 Driving and Operating
2. Push plastic hooks back to engage grilleslats. It is recommended to start with
the lower hooks at the center of the
grille.
3. Repeat for all hooks to fully engage cover to grille.
For vehicles equipped with a front license
plate bracket, only the outer clips will be
engaged on the upper row. Ensure the
top center portion of the cover is
positioned securely behind the license
plate bracket.
4. Make sure all clips remain engaged during installation. Cover should be
stretched to a tight fit when properly
installed.
Engine Heater
The engine heater, if available, can help in
cold weather conditions at or below
−18 °C (0 °F) for easier starting and better
fuel economy during engine warm-up. Plug
in the engine heater at least four hours
before starting the vehicle. An internal
thermostat in the plug end of the cord will
prevent engine heater operation at
temperatures above −18 °C (0 °F).
{Warning
Do not plug in the engine block heater
while the vehicle is parked in a garage or
under a carport. Property damage or
personal injury may result. Always park
the vehicle in a clear open area away
from buildings or structures.
To Use the Engine Heater
1. Turn off the engine.
2. Open the hood and unwrap the electrical
cord. The cord is located on the
passenger side of the compartment near
the air cleaner/filter. Check the heater cord for damage. If it is
damaged, do not use it. See your dealer
for a replacement. Inspect the cord for
damage yearly.
3. Plug it into a normal, grounded 110-volt AC outlet.
{Warning
Improper use of the heater cord or an
extension cord can damage the cord and
may result in overheating and fire.
.Plug the cord into a three-prong
electrical utility receptacle that is
protected by a ground fault detection
function. An ungrounded outlet could
cause an electric shock.
.Use a weatherproof, heavy-duty,
15 amp-rated extension cord if needed.
Failure to use the recommended
extension cord in good operating
condition, or using a damaged heater
or extension cord, could make it
overheat and cause a fire, property
damage, electric shock, and injury.
(Continued)

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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Driving and Operating 179
Warning (Continued)
.Do not operate the vehicle with the
heater cord permanently attached to
the vehicle. Possible heater cord and
thermostat damage could occur.
.While in use, do not let the heater
cord touch vehicle parts or sharp
edges. Never close the hood on the
heater cord.
.Before starting the vehicle, unplug the
cord, reattach the cover to the plug,
and securely fasten the cord. Keep the
cord away from any moving parts.
4. Before starting the engine, be sure to unplug and store the cord as it was
before to keep it away from moving
engine parts. If you do not it could be
damaged.
The length of time the heater should remain
plugged in depends on several factors. Ask a
dealer in the area where you will be parking
the vehicle for the best advice on this.
Retained Accessory Power (RAP)
When the vehicle is turned from on to off,
the following features (if equipped) will
continue to function for up to 10 minutes,
or until the driver door is opened. These
features will also work when the vehicle is
on or in accessory mode:
.Infotainment System
.Power Windows (during RAP this
functionality will be lost when any door
is opened)
.Sunroof (during RAP this functionality will
be lost when any door is opened)
.Auxiliary Power Outlet
.Audio System
.OnStar System
Shifting Into Park
To shift into P (Park): 1. Hold the brake pedal down and set the Electric Parking Brake (EPB). See Electric
Parking Brake 0187.
2. Press the button on top of the shift lever to shift into P (Park). See Automatic
Transmission 0181.
3. The P indicator on the shift lever will turn red when the vehicle is in P (Park). If the vehicle is shifted into P (Park) on a
hill, the Electric Parking Brake (EPB) may
apply automatically. You may not be
able to release the EPB using the EPB
switch. It should automatically release
when the vehicle is shifted out of
P (Park).
Leaving the Vehicle with the Engine
Running
{Warning
It can be dangerous to leave the vehicle
with the engine running. It could
overheat and catch fire.
It is dangerous to get out of the vehicle
if the vehicle is not in P (Park) with the
Electric Parking Brake (EPB) set. The
vehicle can roll.
Do not leave the vehicle when the engine
is running. If you have left the engine
running, the vehicle can move suddenly.
You or others could be injured. To be
sure the vehicle will not move, even
when you are on fairly level ground,
always set the EPB and shift the vehicle
(Continued)

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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Driving and Operating 251
The following advanced driver assistance
features should be turned off when towing
a trailer, and may turn off automatically
when a trailer is detected:
.Park Assist
.Reverse Automatic Braking (RAB)
.Rear Cross Traffic Alert (RCTA)
.Rear Cross Traffic Braking (RCTB)
.Lane Change Alert (LCA)
.Super Cruise and Adaptive Cruise
Control (ACC), unless equipped with
trailering functionality, see Adaptive
Cruise Control (Advanced).
Automatic Emergency Braking (AEB) and
Front Pedestrian Braking (FPB) should be set
to Alert unless equipped with Super Cruise.
Do not use Automatic Parking Assist (APA)
while towing a trailer.
{Warning
To prevent serious injury or death from
carbon monoxide (CO), when towing a
trailer:
.Do not drive with the liftgate, trunk/
hatch, or rear-most window open. (Continued)
Warning (Continued)
.Fully open the air outlets on or under
the instrument panel.
.Adjust the climate control system to a
setting that brings in only outside air.
See“Climate Control Systems” in the
Index.
For more information about carbon
monoxide, see Engine Exhaust 0181.
Towing a trailer requires experience. The
combination of the vehicle and trailer is
longer and not as responsive as the vehicle
itself. Become familiar to the handling and
braking by driving on a level road surface
before driving on public roads.
The trailer structure, the tires, and the
brakes must be all be rated to carry the
intended cargo. Inadequate trailer
equipment can cause the combination to
operate in an unexpected or unsafe manner.
Before driving, inspect all trailer hitch parts
and attachments, safety chains, electrical
connectors, lamps, tires, and mirrors. See
Towing Equipment 0256. If the trailer has
electric brakes, start the combination
moving and then manually apply the trailer
brake controller to check that the trailer brakes work. During the trip, occasionally
check that the cargo and trailer are secure
and that the lamps and any trailer brakes
are working.Towing with a Stability Control System
When towing, the stability control system
might be heard. The system reacts to
vehicle movement caused by the trailer,
which mainly occurs during cornering. This is
normal when towing heavier trailers.
Following Distance
Stay at least twice as far behind the vehicle
ahead as you would when driving without a
trailer. This can help to avoid heavy braking
and sudden turns.
Passing
More passing distance is needed when
towing a trailer. The combination of the
vehicle and trailer will not accelerate as
quickly and is much longer than the vehicle
alone. It is necessary to go much farther
beyond the passed vehicle before returning
to the lane. Pass on level roadways. Avoid
passing on hills if possible.

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
17180837) - 2024 - CRC - 2/28/23
270 Vehicle Care
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 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 the coolantsurge 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.
Automatic Coolant Service Fill
Instructions
This feature assists in filling and removing
air from the cooling system after service of
components or when coolant is added after
being too low.
To activate the fill and air removal process:
1. With a cold system, add coolant to the indicated mark on the surge tank.
2. Replace the cap on the surge tank.
3. Connect the vehicle to a battery charger.

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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276 Vehicle Care
2. Lift up on the latch in the middle of thewiper 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.
Rear Wiper Blade Replacement
To remove the wiper blade:
1. Put the vehicle in accessory mode andturn on the rear windshield wiper. The
wiper will stop pointing down. See Rear
Window Wiper/Washer 090.
2. Push ENGINE START/STOP to turn the vehicle off.
3. Lift the wiper arm away from the window.
4. Push the release lever (2) to disengage the hook and push the wiper arm (1) out
of the blade assembly (3).
5. Push the new blade assembly securely on the wiper arm until the release lever
clicks into place.
6. Start the engine and the rear wiper will return to its normal position.
Windshield Replacement
HUD System
If equipped, the windshield is part of the
HUD system. If the windshield must be
replaced, get one that is designed for HUD
or the HUD image may look out of focus.
Driver Assistance Systems
When a windshield replacement is needed
and the vehicle is equipped with a
front-looking camera sensor for the Driver
Assistance Systems, the windshield must be
installed according to GM specifications for
these systems to work properly. If it is not,
there may be unexpected behavior and/or
messages from these systems.
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.

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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Vehicle Care 303
Tire Chains
{Warning
If the vehicle has 235/60R18 or 245/45R20
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 it contacts the vehicle.
Do not spin the wheels. If traction
devices are used, install them on the
front tires.
Caution
If the vehicle is equipped with a tire size
other than 235/60R18 or 245/45R20, use
tire chains only where legal and only
(Continued)
Caution (Continued)
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
front axle. Do not use chains on the tires
of the rear axle. Tighten them as tightly
as possible with the ends securely
fastened. Drive slowly and follow the
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. SeeTires0286. If air goes out of
a tire, it is much more likely to leak out
slowly. But if there is ever 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 wheel firmly. Steer to
maintain lane position, and then gently
brake to a stop, well off the road,
if possible.
A rear blowout, particularly on a curve, acts
much like a skid and may require the same
correction as used in a skid. Stop pressing
the accelerator pedal and steer to straighten
the vehicle. It may be very bumpy and
noisy. Gently brake to a stop, well off the
road, if possible.
{Warning
Driving on a flat tire will cause
permanent damage to the tire.
Re-inflating a tire after it has been driven
on while severely underinflated or flat
may cause a blowout and a serious crash.
Never attempt to re-inflate a tire that has
been driven on while severely
underinflated or flat. Have your dealer or
an authorized tire service center repair or
replace the flat tire as soon as possible.

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Vehicle Care 317
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.
4. Turn the ignition off. Turn off all lights and accessories in both vehicles, except
the hazard warning flashers if needed.
{Warning
An electric fan can start up even when
the engine is not running and can injure
you. Keep hands, clothing, and tools
away from any underhood electric fan.
{Warning
Using a match near a battery can cause
battery gas to explode. People have been
hurt doing this, and some have been
blinded. Use a flashlight if you need
more light.
(Continued)
Warning (Continued)
Battery fluid contains acid that can burn
you. Do not get it on you. If you
accidentally get it in your eyes or on
your skin, flush the place with water and
get medical help immediately.
{Warning
Fans or other moving engine parts can
injure you badly. Keep your hands away
from moving parts once the engine is
running.
5. Connect one end of the red positive (+) cable to the discharged battery
positive (+) terminal.
6. Connect the other end of the red positive (+) cable to the good battery
positive (+) terminal.
7. Connect one end of the black negative (–) cable to the good battery negative
(–) terminal.
8. Connect the other end of the black negative (–) cable to the discharged
battery negative (–) terminal on the
driver side shock tower. 9. Start the engine in the vehicle with the
good battery and run the engine at idle
speed for at least four minutes.
10. Try to start the vehicle that had the dead battery. If it will not start after a
few tries, it probably needs service.
Jumper Cable Removal
Reverse the sequence exactly when
removing the jumper cables.
After starting the disabled vehicle and
removing the jumper cables, allow it to idle
for several minutes.
Towing the Vehicle
Transporting a Disabled Vehicle
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.

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
17180837) - 2024 - CRC - 2/28/23
320 Vehicle Care
3. Apply the brake pedal and hold until theend of step 5.
4. Push and hold the Electric Parking Brake (EPB) switch. After 15 seconds, the EPB
amber telltale will begin flashing in the
IP cluster.
5. When the indicator flashes amber, release the EPB within five seconds.
Then, push and release the EPB switch
and release the brake pedal.
6. The EPB amber telltale will remain flashing and parking brake will be
released if process is successful.
7. Put the front wheels on the dolly.
8. Shift the transmission to P (Park).
9. Turn the vehicle off.
10. Secure the vehicle to the dolly.
11. Follow the dolly manufacturer's instructions for preparing the vehicle and
dolly for towing.
12. Open the hood.
13. Disconnect the negative (-) terminal connector from the 12–volt battery.
14. Close and latch the hood.
Unloading from the Dolly1. On level ground open the hood. 2. Connect the negative (-) terminal
connector to the 12–volt battery.
3. Close the hood.
4. Follow the dolly manufacturer's instructions for preparing the vehicle and
dolly for unloading.
5. Unsecure the vehicle from the dolly.
6. Start the engine.
7. Shift the transmission to R (Reverse).
8. Drive vehicle off of the dolly.
9. Shift the transmission to P (Park).
10. Apply the brake pedal and hold until step 12.
11. Push and hold the EPB switch for 5 seconds.
12. The EPB amber telltale in the IP cluster will go out.
13. Apply and release Parking Brake by pushing the EPB switch.Towing the Vehicle from the Rear

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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328 Vehicle Care
{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 were
designed for your vehicle. If the floor
mats need to be replaced, it is
recommended that GM-certified floor mats be 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.
Removing and Replacing the Floor Mats
The driver and passenger side floor mats are
held in place by two button-type retainers.
1. Pull up on the rear of the floor mat to
unlock each retainer and remove.
2. Reinstall by lining up the floor mat retainer openings over the carpet
retainers and pushing down to snap into
position.
3. Make sure the floor mat is properly secured in place. Verify the floor mat
does not interfere with the pedals.
Cleaning Rubber Floor Mats (All-Weather
Mats and Floor Liners)
See “Vinyl/Rubber” underInterior Care 0325
for important cleaning information.