ECU CADILLAC CTS 2018 Service Manual

Cadillac CTS/CTS-V Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
11349156) - 2018 - CRC - 9/29/17
DRIVING AND OPERATING 247
.Do not tow a trailer during the
first 2 414 km (1,500 mi) to
prevent damage to the engine,
axle, or other parts.
. Then during the first 800 km
(500 mi) of trailer towing, do not
drive over 80 km/h (50 mph) and
do not make starts at full throttle.
. Vehicles can tow in D (Drive). Shift
the transmission to a lower gear if
the transmission shifts too often
under heavy loads and/or hilly
conditions.
. Do not use Adaptive Cruise
Control when towing.
. The Forward Automatic Braking
System should be set to Off when
towing. See Forward Automatic
Braking (FAB) 0235.
. Turn off Parking Assist when
towing.{Warning
When towing a trailer, exhaust
gases may collect at the rear of the
vehicle and enter if the liftgate,
trunk/hatch, or rear-most window
is open.
When towing a trailer:
. Do not drive with the liftgate,
trunk/hatch, or rear-most
window open.
. Fully open the air outlets on
or under the instrument
panel.
. Also 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
0 199.
Towing a trailer requires a certain
amount of experience. The
combination you are driving is longer and not as responsive as the vehicle
itself. Get acquainted with the
handling and braking of the rig before
setting out for the open road.
Before starting, check all trailer hitch
parts and attachments, safety chains,
electrical connectors, lamps, tires, and
mirrors. If the trailer has electric
brakes, start the combination moving
and then apply the trailer brake
controller by hand to be sure the
brakes work.
During the trip, check occasionally to
be sure that the load is secure and the
lamps and any trailer brakes
still work.
Following Distance
Stay at least twice as far behind the
vehicle ahead as you would when
driving the vehicle 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 will
not accelerate as quickly and is longer

Cadillac CTS/CTS-V Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
11349156) - 2018 - CRC - 9/29/17
VEHICLE CARE 273
1. Remove the coolant surge tankpressure cap from the top
chamber when the cooling
system, including the coolant
surge tank pressure cap and
upper radiator hose, is no
longer hot.
Turn the pressure cap slowly
counterclockwise. If you hear a
hiss, wait for that to stop. This
will allow any pressure still left
to be vented out the
discharge hose.
2. Keep turning the pressure cap slowly and remove it. Open the
surge tank service port cap to
the lower chamber. The service
port is behind the top chamber.
3. Fill the surge tank top chamberwith the proper mixture to the
bottom of the fill neck. The top
chamber needs to be completely
full. Fill the surge tank bottom
chamber through the service port
to approximately half.
4. With the coolant surge tank pressure cap off and the surge
tank service port cap open, start
the engine and let it run until
you can feel the upper radiator
hose getting hot. Watch out for
the engine cooling fan(s).
By this time, the coolant level
inside the coolant surge tank top
chamber may be lower. If the level is lower, add more of the
proper mixture to the surge tank
top chamber until the level
reaches the bottom of the
fill neck.
5. Replace the surge tank pressure cap tightly and close the surge
tank service port cap.
6. Check the level in the surge tank top and bottom chambers when
the cooling system has cooled
down. If the coolant is not at the
proper levels, repeat Steps 1–
6 and reinstall the pressure cap
and close the service port. If the
coolant still is not at the proper
levels when the system cools
down again, see your dealer.
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 CTS/CTS-V Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
11349156) - 2018 - CRC - 9/29/17
VEHICLE CARE 293
FusesUsage
26 Front ventilated seats
27 Side blind zone alert/Lane departure warning/External
object calculating module
28 Trailer/Sunshade
29 Rear heated seats
30 Semi-active damping system
31 Transfer case control module/Rear control drive
module
32 Theft module/Universal garage door opener/Rain
sensor
33 Ultrasonic parking assist
34 Radio/DVD
35 –/Exhaust valve (V-series)
36 Trailer
37 Fuel system control module Fuses
Usage
38 Fuel pump prime/Exhaust valve (V-series)
39 –
42 Memory seat module
43 Body control module 3
44 –
45 Battery regulated voltage control
46 Engine control module/ Battery
47 –
48 –
49 Trailer module
53 –
55 – Relays
Usage
17 Trailer
18 Logistics
20 Rear window defogger
40 Run crank 2 (V-series)
41 Fuel pump prime/ Run crank 2
50 Child door lock security
51 Rear closure
52 Rear closure 2
54 Door lock security
56 Fuel door

Cadillac CTS/CTS-V Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
11349156) - 2018 - CRC - 9/29/17
314 VEHICLE CARE
Warning (Continued)
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 rear tires.
Caution
If the vehicle is equipped with a tire
size other than P245/40R18,
245/40R18, 275/35R18, 255/35R19,
265/35ZR19, or 295/30ZR19 use tire
chains only where legal and only
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 rear
axle. Don't use chains on the tires(Continued)
Caution (Continued)
of the front 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
If the vehicle has run-flat tires, there
is no need to stop on the side of the
road to change a flat tire. See Run-Flat
Tires 0295.
{Warning
Special tools and procedures are
required to service a run-flat tire.
If these special tools and
procedures are not used, injury or
vehicle damage may occur. Always
(Continued)
Warning (Continued)
be sure the proper tools and
procedures, as described in the
service manual, are used.
It is unusual for a tire to blow out
while driving, especially if the tires are
maintained properly. See Tires0294.
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

Cadillac CTS/CTS-V Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
11349156) - 2018 - CRC - 9/29/17
VEHICLE CARE 325
{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 remote
positive (+) terminal on the
discharged battery.
6. Connect the other end of the red positive (+) cable to the
positive (+) terminal of the good
battery.
7. Connect one end of the black negative (–) cable to the
negative (–) terminal of the good
battery.
8. Connect the other end of the black negative (–) cable to the
remote negative (–) grounding
terminal for the discharged
battery. 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.
Caution
If the jumper cables are connected
or removed in the wrong order,
electrical shorting may occur and
damage the vehicle. The repairs
would not be covered by the vehicle
warranty. Always connect and
remove the jumper cables in the
correct order, making sure that the
cables do not touch each other or
other metal.
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
Caution
Incorrectly towing a disabled
vehicle may cause damage. The
damage would not be covered by
the vehicle warranty.
Do not lash or hook to suspension
components. Use the proper straps
around the tires to secure the
vehicle.
Use only a flatbed tow truck for
towing a disabled vehicle. Never use a
sling type lift or damage will occur.
Use ramps to help reduce approach
angles if necessary. A towed vehicle
should have its drive wheels off the
ground. Consult a professional towing
service if the disabled vehicle must be
towed.

Cadillac CTS/CTS-V Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
11349156) - 2018 - CRC - 9/29/17
328 VEHICLE CARE
Dolly Towing (Rear-Wheel-Drive
Vehicles)
To dolly tow a rear-wheel-drive vehicle
from the rear:1. Attach the dolly to the tow vehicle following the dolly
manufacturer instructions.
2. Put the rear wheels on the dolly.
3. Shift the transmission to P (Park).
4. Firmly set the parking brake. 5. Use an adequate clamping device
designed for towing to ensure
that the front wheels are locked
into the straight-ahead position.
6. Secure the vehicle to the dolly following the manufacturer
instructions.
7. Release the parking brake only after the vehicle being towed is
firmly attached to the towing
vehicle.
8. Turn the ignition to off.
Dolly Towing (All-Wheel Drive
Vehicles)
Vehicles with all-wheel drive cannot
be dolly towed.

Cadillac CTS/CTS-V Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
11349156) - 2018 - CRC - 9/29/17
336 VEHICLE CARE
Care of Seat Belts
Keep belts clean and dry.
{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 usage.
.
The original equipment floor mats
were designed for your vehicle.
If the floor mats need replacing, 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.
The driver side floor mat is held in
place by two button-type retainers.
Removing and Replacing the
Floor Mats
1. Pull up on the rear of the floor mat to unlock the retainers and
remove.
2. Reinstall by lining up the floor mat retainer openings over the
carpet retainers and snap into
position.
3. Make sure the floor mat is properly secured in place. Verify
the floor mat does not interfere
with the pedals.

Cadillac CTS/CTS-V Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
11349156) - 2018 - CRC - 9/29/17
CUSTOMER INFORMATION 361
General Motors of Canada also has a
Mobility program. See www.gm.ca or
call 1-800-GM-DRIVE (800-463-7483)
for details. TTY users call
1-800-263-3830.
Roadside Service
U.S.: 1-800-224-1400.
Canada: 1-800-882-1112.
Text Telephone (TTY) Users (U.S.
Only): 1-888-889-2438.
Service is available 24 hours a day,
365 days a year.
Calling for Service
When calling Roadside Service, have
the following information ready:
.Your name, home address, and
home telephone number
. Telephone number of your
location
. Location of the vehicle
. Model, year, color, and license
plate number of the vehicle .
Odometer reading, Vehicle
Identification Number (VIN), and
delivery date of the vehicle
. Description of the problem
Coverage
Services are provided for the duration
of the vehicle’s powertrain warranty.
In the U.S., anyone driving the vehicle
is covered. In Canada, a person driving
the vehicle without permission from
the owner is not covered.
Roadside Service is not a part of the
New Vehicle Limited Warranty.
General Motors North America and
Cadillac reserve the right to make any
changes or discontinue the Roadside
Service program at any time without
notification.
General Motors North America and
Cadillac reserve the right to limit
services or payment to an owner or
driver if they decide the claims are
made too often, or the same type of
claim is made many times.
Cadillac Owner Privileges ™
.
Emergency Fuel Delivery:
Delivery of enough fuel for the
vehicle to get to the nearest
service station.
. Lock-Out Service: Service to
unlock the vehicle if you are
locked out. A remote unlock may
be available if you have OnStar.
For security reasons, the driver
must present identification before
this service is given.
. Emergency Tow from a Public
Road or Highway: Tow to the
nearest Cadillac dealer for
warranty service, or if the vehicle
was in a crash and cannot be
driven. Assistance is not given
when the vehicle is stuck in the
sand, mud, or snow.
. Flat Tire Change: Service to
change a flat tire with a spare tire.
The spare tire, if equipped, must
be in good condition and properly
inflated. It is your responsibility
for the repair or replacement of
the tire if it is not covered by the
warranty.

Cadillac CTS/CTS-V Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
11349156) - 2018 - CRC - 10/2/17
ONSTAR 371
OnStar
OnStar Overview
OnStar Overview . . . . . . . . . . . . . . . . . . 371
OnStar Services
Emergency . . . . . . . . . . . . . . . . . . . . . . . . 372
Security . . . . . . . . . . . . . . . . . . . . . . . . . . . 373
Navigation . . . . . . . . . . . . . . . . . . . . . . . . 373
Connections . . . . . . . . . . . . . . . . . . . . . . 374
Diagnostics . . . . . . . . . . . . . . . . . . . . . . . 376
OnStar Additional Information
OnStar AdditionalInformation . . . . . . . . . . . . . . . . . . . . . 377
OnStar Overview
=Voice Command Button
QBlue OnStar Button
>Red Emergency Button
This vehicle may be equipped with a
comprehensive, in-vehicle system that
can connect to an OnStar Advisor for
Emergency, Security, Navigation,
Connections, and Diagnostics Services.
OnStar services may require a paid
service plan and data plan. OnStar
requires the vehicle battery and
electrical system, cellular service, and
GPS satellite signals to be available
and operating. OnStar acts as a link to
existing emergency service providers.
OnStar may collect information about you and your vehicle, including
location information. See OnStar User
Terms, Privacy Statement, and
Software Terms for more details
including system limitations at
www.onstar.com (U.S.) or
www.onstar.ca (Canada).
The OnStar system status light is next
to the OnStar buttons. If the status
light is:
.
Solid Green: System is ready.
. Flashing Green: On a call.
. Red: Indicates a problem.
. Off: System is active. Press
Q
twice to speak with an OnStar
Advisor.
Press
Qor call 1-888-4ONSTAR
(1-888-466-7827) to speak to an
Advisor.
Functionality of the Voice Command
button may vary by vehicle and
region.

Cadillac CTS/CTS-V Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
11349156) - 2018 - CRC - 10/2/17
ONSTAR 373
Security
If equipped, OnStar provides these
services:
.With Stolen Vehicle Assistance,
OnStar Advisors can use GPS to
pinpoint the vehicle and help
authorities quickly recover it.
. With Remote Ignition Block,
if equipped, OnStar can block the
engine from being restarted.
. With Stolen Vehicle Slowdown,
if equipped, OnStar can work with
law enforcement to gradually slow
the vehicle down.
Theft Alarm Notification
If equipped, if the doors are locked
and the vehicle alarm sounds, a
notification by text, e-mail, or phone
call will be sent. If the vehicle is
stolen, an OnStar Advisor can work
with authorities to recover the vehicle.
Navigation
OnStar navigation requires a specific
OnStar or connected service plan. Press
Qto receive Turn-by-Turn
directions or have them sent to the
vehicle’s navigation screen,
if equipped.
Turn-by-Turn Navigation
1. PressQto connect to an
Advisor.
2. Request directions to be downloaded to the vehicle.
3. Follow the voice-guided commands.
Using Voice Commands During a
Planned Route
Functionality of the Voice Command
button may vary by vehicle and
region. For some vehicles, press
=to
open the OnStar app on the
infotainment display. For other
vehicles press
=as follows.
Cancel Route
1. Press
=. System responds:
“OnStar ready,” then a tone. 2. Say
“Cancel route.” System
responds: “Do you want to cancel
directions?”
3. Say “Yes.”System responds: “OK,
request completed, thank you,
goodbye.”
Route Preview
1. Press
=. System responds:
“OnStar ready,” then a tone.
2. Say “Route preview.” System
responds with the next three
maneuvers.
Repeat
1. Press
=. System responds:
“OnStar ready,” then a tone.
2. Say “Repeat.” System responds
with the last direction given,
then responds with “OnStar
ready,” then a tone.
Get My Destination
1. Press
=. System responds:
“OnStar ready,” then a tone.