check engine CADILLAC CT6 2018 1.G Service Manual

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/15/17
326 VEHICLE CARE
Extended Storage: Remove the 12-volt
battery black, negative (−) cable from
the battery or use a battery trickle
charger.
Remember to reconnect the battery
when ready to drive the vehicle.
All-Wheel Drive
If the vehicle is equipped with
All-Wheel Drive (AWD), this is an
additional system that needs
lubrication.
Transfer Case
When to Check Lubricant
It is not necessary to regularly check
the transfer case fluid unless a leak is
suspected or an unusual noise is
heard. A fluid loss could indicate a
problem. Have it inspected and
repaired.How to Check Lubricant1. Fill Plug
2. Drain Plug
To get an accurate reading, the vehicle
should be on a level surface.
If the level is below the bottom of the
fill plug hole on the transfer case,
some lubricant will need to be added.
Add enough lubricant to raise the
level to the bottom of the fill plug
hole. Use care not to overtighten the
fill plug.What to Use
To determine what kind of lubricant
to use, see
Recommended Fluids and
Lubricants 0399.
Starter Switch Check
{Warning
When you are doing this inspection,
the vehicle could move suddenly.
If the vehicle moves, you or others
could be injured.
1. Before starting this check, be sure there is enough room
around the vehicle.
2. Firmly apply both the parking brake and the regular brake. Do
not use the accelerator pedal,
and be ready to turn off the
engine immediately if it starts.
3. Try to start the engine in each gear. The vehicle should start
only in P (Park) or N (Neutral).
If the vehicle starts in any other
position, contact your dealer for
service.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/15/17
VEHICLE CARE 327
Automatic Transmission
Shift Lock Control Function
Check
{Warning
When you are doing this inspection,
the vehicle could move suddenly.
If the vehicle moves, you or others
could be injured.
1. Before starting this check, be sure there is enough room
around the vehicle. It should be
parked on a level surface.
2. Firmly apply the parking brake. See Electric Parking Brake 0235.
Be ready to apply the regular
brake immediately if the vehicle
begins to move.
3. With the engine off, turn the ignition on, but do not start the
engine. Without applying the
regular brake, try to move the
shift lever out of P (Park) with
normal effort. If the shift lever
moves out of P (Park), contact
your dealer for service.
Park Brake and P (Park)
Mechanism Check
{Warning
When you are doing this check, the
vehicle could begin to move. You or
others could be injured and
property could be damaged. Make
sure there is room in front of the
vehicle in case it begins to roll. Be
ready to apply the regular brake at
once should the vehicle begin
to move.
Park on a fairly steep hill, with the
vehicle facing downhill. Keeping your
foot on the regular brake, set the
parking brake.
. To check the parking brake's
holding ability: With the engine
running and the transmission in
N (Neutral), slowly remove foot
pressure from the regular brake
pedal. Do this until the vehicle is
held by the parking brake only. .
To check the P (Park) mechanism's
holding ability: With the engine
running, shift to P (Park). Then
release the parking brake followed
by the regular brake.
Contact your dealer if service is
required.
Wiper Blade Replacement
Windshield wiper blades should be
inspected for wear or cracking.
For the proper type and size, see
Maintenance Replacement Parts 0400.
To replace the wiper blade assembly: 1. Pull the windshield wiper assembly away from the
windshield.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/15/17
332 VEHICLE CARE
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 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 CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/15/17
VEHICLE CARE 339
FusesUsage
F28 Amplifier
F29 Sunroof
F30 Body control module 2
F31 Body control module 6
F32 Exterior heated mirrors
F33 Right window
F34 Power trunk module
F35 On-board charging module
F36 Alarm siren module
F37 DC AC inverter
F38 Rear blower
F39 Fuel pump power
F40 –
F41 Rear seat power outlet
F42 Left rear memory seat
F43 – Fuses
Usage
F44 Rear closure
F45 Auxiliary audio/ Video/Radio
F46 External object calculating/Side blind
zone alert/Radar
short range sensor
F47 –
F48 Right front seat
F49 Memory bolster module
F50 Body control module 1
F51 Transmission control module
F52 Parking assist
F53 Ventilated seats
F54 Headliner
F55 Front memory seat module
F56 Evaporative emissions leak check
module Fuses
Usage
F57 Voltage current temperature module
F58 –
F59 Engine control module battery
F60 Right motorized seat belt pretensioner
F61 Parking lamps
F62 –
F63 –
F64 Engine control module ignition
F65 Rear window sunshade
F66 Rear vision camera/ Interior rearview
mirror
F67 DC DC converter/Air quality sensor
F68 Damping control module
F69 Television tuner module

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/15/17
VEHICLE CARE 375
The jump start negative terminal (3)
and positive terminal (4) are on the
battery of the vehicle providing the
jump start.
The positive jump start connection for
the discharged battery is under a red
cover. Remove the cover to expose the
terminal.1. Check the other vehicle. It must have a 12-volt battery with a
negative ground system.
Caution
If the other vehicle does not have a
12-volt system with a negative
ground, both vehicles can be
damaged. Only use a vehicle that
has a 12-volt system with a
negative ground for jump starting.
2. Position the two vehicles so that they are not touching.
3. Set the parking brake firmly and put the shift lever in P (Park). See
Shifting Into Park 0224.
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.
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 remote
positive (+) terminal on the
discharged battery.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
390 SERVICE AND MAINTENANCE
Cadillac Premium Care
Maintenance
Your vehicle comes with the Cadillac
Premium Care Maintenance. It is a
maintenance program that covers
select maintenance services during
the first three years or 58 000 km
(36,000 mi) whichever comes first.
Cadillac Premium Care Maintenance
covers routine maintenance services,
when scheduled in accordance with
the owner’s manual, including:
.Oil changes based on the vehicle's
oil life monitor system.
. Tire rotation every 12 000 km
(7,500 mi).
. Passenger compartment air filter
replacement.
. Multi-point vehicle inspection
(MPVI) performed by a qualified
technician.
Cadillac requires that all Cadillac
Premium Care Maintenance services
be performed by a Cadillac authorized
service dealer.
Maintenance Schedule
Owner Checks and Services
At Each Fuel Stop
. Check the engine oil level. See
Engine Oil 0307.
Once a Month
. Check the tire inflation pressures.
See Tire Pressure 0347.
. Inspect the tires for wear. See Tire
Inspection 0353.
. Check the windshield washer fluid
level. See Washer Fluid 0322.
Engine Oil Change
When the CHANGE ENGINE OIL
SOON message displays, have the
engine oil and filter changed within
the next 1 000 km/600 mi. If driven
under the best conditions, the engine
oil life system may not indicate the
need for vehicle service for up to a
year. The engine oil and filter must be
changed at least once a year and the
oil life system must be reset. Your
trained dealer technician can perform
this work. If the engine oil life system is reset accidentally, service the
vehicle within 5 000 km/3,000 mi since
the last service. Reset the oil life
system when the oil is changed. See
Engine Oil Life System
0309.
Tire Rotation and Required
Services Every 12 000 km/
7,500 mi
Rotate the tires, if recommended for
the vehicle, and perform the following
services. See Tire Rotation0353.
. Check engine oil level and oil
life percentage. If needed, change
engine oil and filter, and reset oil
life system.
See Engine Oil 0307 and Engine Oil
Life System 0309.
. Check engine coolant level.
See Cooling System (Gasoline Only)
0 312 orCooling System (PLUG-IN
Only) 0316.
. Check windshield washer fluid
level. See Washer Fluid 0322.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
SERVICE AND MAINTENANCE 391
.Visually inspect windshield wiper
blades for wear, cracking,
or contamination. See Exterior
Care 0380. Replace worn or
damaged wiper blades. See Wiper
Blade Replacement 0327.
. Check tire inflation pressures. See
Tire Pressure 0347.
. Inspect tire wear. See Tire
Inspection 0353.
. Visually check for fluid leaks.
. Inspect engine air cleaner filter.
See Engine Air Cleaner/Filter 0311.
. Inspect brake system. See Exterior
Care 0380.
. Visually inspect steering,
suspension, and chassis
components for damaged, loose,
or missing parts or signs of wear.
See Exterior Care 0380.
. Check restraint system
components. See Safety System
Check 083.
. Visually inspect fuel system for
damage or leaks. .
Visually inspect exhaust system
and nearby heat shields for loose
or damaged parts.
. Lubricate body components. See
Exterior Care 0380.
. Check starter switch. See Starter
Switch Check 0326.
. Check automatic transmission
shift lock control function. See
Automatic Transmission Shift Lock
Control Function Check 0327.
. Check parking brake and
automatic transmission park
mechanism. See Park Brake and
P (Park) Mechanism Check 0327.
. Check accelerator pedal for
damage, high effort, or binding.
Replace if needed.
. Visually inspect gas strut for signs
of wear, cracks, or other damage.
Check the hold open ability of the
strut. If the hold open ability is
low, service the gas strut. See Gas
Strut(s) 0328.
. Inspect sunroof track and seal,
if equipped. See Sunroof061.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
392 SERVICE AND MAINTENANCE
Maintenance Schedule
Additional Required Services -
Normal12 000 km/7,500 mi
24 000 km/15,000 mi
36 000 km/22,500 mi
48 000 km/30,000 mi
60 000 km/37,500 mi
72 000 km/45,000 mi
84 000 km/52,500 mi
96 000 km/60,000 mi
108 000 km/67,500 mi
120 000 km/75,000 mi
132 000 km/82,500 mi
144 000 km/90,000 mi
156 000 km/97,500 mi
168 000 km/105,000 mi
180 000 km/112,500 mi
192 000 km/120,000 mi
204 000 km/127,500 mi
216 000 km/135,000 mi
228 000 km/142,500 mi
240 000 km/150,000 mi
Rotate tires, if recommended for the vehicle, and
perform Required Services. Check engine oil level
and oil life percentage. Change engine oil and filter,
if needed. (1)@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
Replace passenger compartment air filter. (2)@ @@@@@
Inspect evaporative control system. (3)@ @@
Replace engine air cleaner filter. (4)@@@
Replace spark plugs. Inspect spark plug wires. (2.0L
and 3.0L Twin Turbo Engines)@ @
Replace spark plugs. Inspect spark plug wires. (3.6L
Engine Only)@
Drain and fill engine cooling system and Power
Electronics cooling system. (5)@
Change transfer case fluid, if equipped with
AWD. (6)@
Change rear axle fluid.@
Visually inspect accessory drive belts. (7)@
Replace brake fluid. (8)

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
394 SERVICE AND MAINTENANCE
Maintenance Schedule
Additional Required Services -
Severe12 000 km/7,500 mi
24 000 km/15,000 mi
36 000 km/22,500 mi
48 000 km/30,000 mi
60 000 km/37,500 mi
72 000 km/45,000 mi
84 000 km/52,500 mi
96 000 km/60,000 mi
108 000 km/67,500 mi
120 000 km/75,000 mi
132 000 km/82,500 mi
144 000 km/90,000 mi
156 000 km/97,500 mi
168 000 km/105,000 mi
180 000 km/112,500 mi
192 000 km/120,000 mi
204 000 km/127,500 mi
216 000 km/135,000 mi
228 000 km/142,500 mi
240 000 km/150,000 mi
Rotate tires, if recommended for the vehicle, and
perform Required Services. Check engine oil level
and oil life percentage. Change engine oil and filter,
if needed. (1)@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
Replace passenger compartment air filter. (2)@ @@@@@
Inspect evaporative control system. (3)@ @@
Replace engine air cleaner filter. (4)@@@
Replace spark plugs. Inspect spark plug wires. (2.0L
and 3.0L Twin Turbo Engines)@ @
Replace spark plugs. Inspect spark plug wires. (3.6L
Engine Only)@
Change automatic transmission fluid and filter.@@@
Change transfer case fluid, if equipped with
AWD. (5)@@@
Change rear axle fluid.@@@
Change front axle fluid, if equipped with AWD.@@@
Drain and fill engine cooling system and Power
Electronics cooling system. (6)@
Visually inspect accessory drive belts. (7)@
Replace brake fluid. (8)

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
396 SERVICE AND MAINTENANCE
Additional Maintenance
and Care
Your vehicle is an important
investment and caring for it properly
may help to avoid future costly
repairs. To maintain vehicle
performance, additional maintenance
services may be required.
It is recommended that your dealer
perform these services—their trained
dealer technicians know your vehicle
best. Your dealer can also perform a
thorough assessment with a
multi-point inspection to recommend
when your vehicle may need
attention.
The following list is intended to
explain the services and conditions to
look for that may indicate services are
required.
Battery
The 12-volt battery supplies power to
start the engine and operate any
additional electrical accessories.
. To avoid break-down or failure to
start the vehicle, maintain a
battery with full cranking power. .
Trained dealer technicians have
the diagnostic equipment to test
the battery and ensure that the
connections and cables are
corrosion-free.
Belts
. Belts may need replacing if they
squeak or show signs of cracking
or splitting.
. Trained dealer technicians have
access to tools and equipment to
inspect the belts and recommend
adjustment or replacement when
necessary.
Brakes
Brakes stop the vehicle and are crucial
to safe driving.
. Signs of brake wear may include
chirping, grinding, or squealing
noises, or difficulty stopping.
. Trained dealer technicians have
access to tools and equipment to
inspect the brakes and recommend
quality parts engineered for the
vehicle. Fluids
Proper fluid levels and approved fluids
protect the vehicle’s systems and
components. See
Recommended Fluids
and Lubricants 0399 for GM approved
fluids.
. Engine oil and windshield washer
fluid levels should be checked at
every fuel fill.
. Instrument cluster lights may
come on to indicate that fluids
may be low and need to be filled.
Hoses
Hoses transport fluids and should be
regularly inspected to ensure that
there are no cracks or leaks. With a
multi-point inspection, your dealer
can inspect the hoses and advise if
replacement is needed.
Lamps
Properly working headlamps,
taillamps, and brake lamps are
important to see and be seen on
the road.
. Signs that the headlamps need
attention include dimming, failure
to light, cracking, or damage. The