check engine BUICK LACROSSE 2018 Owner's Guide

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
224 Driving and Operating
Maintenance when Trailer
Towing
The vehicle needs service more
often when pulling a trailer. See
Maintenance Schedule0311.
Things that are especially important
in trailer operation are automatic
transmission fluid, engine oil, axle
lubricant, belts, cooling system, and
brake system. It is a good idea to
inspect these before and during
the trip.
Check periodically to see that all
hitch nuts and bolts are tight.
Trailer Towing
Before pulling a trailer, three
important considerations have to do
with weight:
. Weight of the trailer
. Weight of the trailer tongue
. Total weight on your vehicle's
tires
Weight of the Trailer
How heavy can a trailer safely be?
It should never weigh more than
454 kg (1,000 lb). But even that can
be too heavy.
It depends on how the rig is used.
For example, speed, altitude, road
grades, outside temperature, the
dimensions of the front of the trailer,
and how much the vehicle is used
to pull a trailer are all important.
It can depend on any special
equipment on the vehicle, and the
amount of tongue weight the vehicle
can carry. See “Weight of the Trailer
Tongue” following.
Maximum trailer weight is calculated
assuming the tow vehicle has the
driver, a front seat passenger, all the
required tow equipment, and all the
required trailering equipment. The
weight of additional optional
equipment, passengers, and cargo
in the tow vehicle must be
subtracted from the maximum trailer
weight. Ask your dealer for trailering
information or advice, or write us at
our Customer Assistance Offices.
See
Customer Assistance Offices
0 327.
Weight of the Trailer Tongue
The tongue load (1) of any trailer is
an important weight to measure
because it affects the total gross
weight of the vehicle. The Gross
Vehicle Weight (GVW) includes the
curb weight of the vehicle, any
cargo carried in it, and the people
who will be riding in the vehicle.
If there are a lot of options,
equipment, passengers, or cargo in
the vehicle, it will reduce the tongue
weight the vehicle can carry, which
will also reduce the trailer weight the
vehicle can tow. If towing a trailer,
the tongue load must be added to
the GVW because the vehicle will
be carrying that weight, too. See
Vehicle Load Limits 0166.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
226 Driving and Operating
Conversions and
Add-Ons
Add-On Electrical
Equipment
{Warning
The Data Link Connector (DLC) is
used for vehicle service and
Emission Inspection/Maintenance
testing. SeeMalfunction Indicator
Lamp (Check Engine Light) 0117.
A device connected to the DLC —
such as an aftermarket fleet or
driver-behavior tracking device —
may interfere with vehicle
systems. This could affect vehicle
operation and cause a crash.
Such devices may also access
information stored in the vehicle’s
systems.
Caution
Some electrical equipment can
damage the vehicle or cause
components to not work and
would not be covered by the
vehicle warranty. Always check
with your dealer before adding
electrical equipment.
Add-on equipment can drain the
vehicle's 12-volt battery, even if the
vehicle is not operating.
The vehicle has an airbag system.
Before attempting to add anything
electrical to the vehicle, see
Servicing the Airbag-Equipped
Vehicle 079 and Adding Equipment
to the Airbag-Equipped Vehicle
0 79.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
Vehicle Care 227
Vehicle Care
General Information
General Information . . . . . . . . . . 228
California Proposition65 Warning . . . . . . . . . . . . . . . . . 228
California Perchlorate Materials Requirements . . . . . 229
Accessories and Modifications . . . . . . . . . . . . . . . . 229
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 229
Hood . . . . . . . . . . . . . . . . . . . . . . . . . 230
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . 231
Engine Oil . . . . . . . . . . . . . . . . . . . . 234
Engine Oil Life System . . . . . . . 237
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . 238
Engine Air Cleaner/Filter . . . . . . 238
Cooling System . . . . . . . . . . . . . . 239
Engine Overheating . . . . . . . . . . 243
Overheated Engine Protection Operating Mode . . . . . . . . . . . . . 244
Washer Fluid . . . . . . . . . . . . . . . . . 245
Brakes . . . . . . . . . . . . . . . . . . . . . . . 245
Brake Fluid . . . . . . . . . . . . . . . . . . . 246
Battery - North America . . . . . . 247 All-Wheel Drive . . . . . . . . . . . . . . . 248
Starter Switch Check . . . . . . . . . 248
Wiper Blade Replacement . . . . 249
Windshield Replacement . . . . . 249
Gas Strut(s) . . . . . . . . . . . . . . . . . . 249
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . 251
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . 251
High Intensity Discharge (HID)
Lighting . . . . . . . . . . . . . . . . . . . . . 251
LED Lighting . . . . . . . . . . . . . . . . . 251
Taillamps, Turn Signal, Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . . . 251
License Plate Lamp . . . . . . . . . . 252
Electrical System
Electrical System Overload . . . 253
Fuses and Circuit Breakers . . . 253
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 254
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 257
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 259
All-Season Tires . . . . . . . . . . . . . . 260
Winter Tires . . . . . . . . . . . . . . . . . . 260
Tire Sidewall Labeling . . . . . . . . 261 Tire Designations . . . . . . . . . . . . . 263
Tire Terminology and
Definitions . . . . . . . . . . . . . . . . . . 264
Tire Pressure . . . . . . . . . . . . . . . . . 266
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . 267
Tire Pressure Monitor System . . . . . . . . . . . . . . . . . . . . . . 268
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . . . 269
Tire Inspection . . . . . . . . . . . . . . . . 272
Tire Rotation . . . . . . . . . . . . . . . . . 272
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . 273
Buying New Tires . . . . . . . . . . . . . 274
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . . . . 275
Uniform Tire Quality Grading . . . . . . . . . . . . . . . . . . . . . 276
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . . . 277
Wheel Replacement . . . . . . . . . . 277
Tire Chains . . . . . . . . . . . . . . . . . . . 278
If a Tire Goes Flat . . . . . . . . . . . . 279
Tire Sealant and Compressor Kit . . . . . . . . . . . . . 280
Storing the Tire Sealant and Compressor Kit . . . . . . . . . . . . . 287
Tire Changing . . . . . . . . . . . . . . . . 287
Compact Spare Tire . . . . . . . . . . 292

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
234 Vehicle Care
1. Windshield Washer FluidReservoir. See Washer Fluid
0 245.
2. Engine Oil Fill Cap. See Engine Oil 0234.
3. Engine Oil Dipstick. See Engine Oil 0234.
4. Engine Cooling Fan (Out of View). See Cooling System
0 239.
5. Brake Fluid Reservoir. See Brake Fluid 0246.
6. Engine Air Cleaner/Filter 0238.
7. Coolant Surge Tank and Pressure Cap. See Cooling
System 0239.
8. Remote Positive (+) Battery Terminal (Under Cover).
See Jump Starting - North
America (with or without
eAssist) 0294 orJump Starting
- North America (On-board with
eAssist Only) 0293.
9. Remote Negative (-) Battery Terminal.
See Jump Starting - North
America (with or without eAssist)
0293 orJump Starting
- North America (On-board with
eAssist Only) 0293.
10. Engine Compartment Fuse
Block 0254.
Engine Oil
To ensure proper engine
performance and long life, careful
attention must be paid to engine oil.
Following these simple, but
important steps will help protect
your investment:
.
Use engine oil approved to the
proper specification and of the
proper viscosity grade. See
“Selecting the Right Engine Oil”
in this section.
. Check the engine oil level
regularly and maintain the
proper oil level. See “Checking
Engine Oil” and“When to Add
Engine Oil” in this section.
. Change the engine oil at the
appropriate time. See Engine Oil
Life System 0237. .
Always dispose of engine oil
properly. See “What to Do with
Used Oil” in this section.
Checking Engine Oil
Check the engine oil level regularly,
every 650 km (400 mi), especially
prior to a long trip. The engine oil
dipstick handle is a loop. See
Engine Compartment Overview
0231 for the location.
{Warning
The engine oil dipstick handle
may be hot; it could burn you.
Use a towel or glove to touch the
dipstick handle.
If a low oil Driver Information Center
(DIC) message displays, check the
oil level.
Follow these guidelines:
. To get an accurate reading, park
the vehicle on level ground.
Check the engine oil level after
the engine has been off for at
least two hours. Checking the
engine oil level on steep grades

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
Vehicle Care 235
or too soon after engine shutoff
can result in incorrect readings.
Accuracy improves when
checking a cold engine prior to
starting. Remove the dipstick
and check the level.
. If unable to wait two hours, the
engine must be off for at least
15 minutes if the engine is
warm, or at least 30 minutes if
the engine is not warm. Pull out
the dipstick, wipe it with a clean
paper towel or cloth, then push it
back in all the way. Remove it
again, keeping the tip down, and
check the level.
When to Add Engine Oil
2.5L L4 Engine
3.6L V6 Engine
If the oil is below the cross-hatched
area at the tip of the dipstick and
the engine has been off for at least
15 minutes, add 1 L (1 qt) of the
recommended oil and then recheck
the level. See “Selecting the Right
Engine Oil” later in this section for
an explanation of what kind of oil to
use. For engine oil crankcase
capacity, see Capacities and
Specifications 0323.
Caution
Do not add too much oil. Oil
levels above or below the
acceptable operating range
shown on the dipstick are harmful
(Continued)
Caution (Continued)
to the engine. If you find that you
have an oil level above the
operating range, i.e., the engine
has so much oil that the oil level
gets above the cross-hatched
area that shows the proper
operating range, the engine could
be damaged. You should drain
out the excess oil or limit driving
of the vehicle and seek a service
professional to remove the
excess amount of oil.
See Engine Compartment Overview
0 231 for the location of the engine
oil fill cap.
Add enough oil to put the level
somewhere in the proper operating
range. Push the dipstick all the way
back in when through.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
Vehicle Care 237
Engine Oil Life System
When to Change Engine Oil
This vehicle has a computer system
that indicates when to change the
engine oil and filter. This is based
on a combination of factors which
include engine revolutions, engine
temperature, and miles driven.
Based on driving conditions, the
mileage at which an oil change is
indicated can vary considerably. For
the oil life system to work properly,
the system must be reset every time
the oil is changed.
When the system has calculated
that oil life has been diminished, it
indicates that an oil change is
necessary. A CHANGE ENGINE
OIL SOON message comes on.
Change the oil as soon as possible
within the next 1 000 km (600 mi).
It is possible that, if driving under
the best conditions, the oil life
system may indicate that an oil
change is not necessary for up to a
year. The engine oil and filter must
be changed at least once a year
and at this time the system must be
reset. Your dealer has trainedservice people who will perform this
work and reset the system. It is also
important to check the oil regularly
over the course of an oil drain
interval and keep it at the proper
level.
If the system is ever reset
accidentally, the oil must be
changed at 5 000 km (3,000 mi)
since the last oil change.
Remember to reset the oil life
system whenever the oil is changed.
How to Reset the Engine Oil
Life System
Reset the system whenever the
engine oil is changed so that the
system can calculate the next
engine oil change. To reset the
system:
1. Using the DIC controls on the right side of the steering wheel,
display REMAINING OIL LIFE
on the DIC. See Driver
Information Center (DIC) 0126.
When remaining oil life is low,
the CHANGE ENGINE OIL
SOON message will appear on
the display. 2. Press
Von the DIC controls
and hold down for a few
seconds to clear the CHANGE
ENGINE OIL SOON message
and reset the oil life at 100%.
Be careful not to reset the oil
life display accidentally at any
time other than after the oil is
changed. It cannot be reset
accurately until the next oil
change.
The system is reset when the
CHANGE ENGINE OIL SOON
message is off.
If the CHANGE ENGINE OIL SOON
message comes back on when the
vehicle is started, the engine oil life
system has not been reset. Repeat
the procedure.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
238 Vehicle Care
Automatic Transmission
Fluid
How to Check Automatic
Transmission Fluid
It is not necessary to check the
transmission fluid level.
A transmission fluid leak is the only
reason for fluid loss. If a leak
occurs, take the vehicle to your
dealer service department and have
it repaired as soon as possible.
There is a special procedure for
checking and changing the
transmission fluid. Because this
procedure is difficult, you should
have this done at your dealer
service department. Contact your
dealer for additional information or
the procedure can be found in the
service manual. To purchase a
service manual, seeService
Publications Ordering Information
0 334.
Change the fluid at the intervals
listed in Maintenance Schedule
0 311, and be sure to use the fluid
listed in Recommended Fluids and
Lubricants 0319.
Engine Air Cleaner/Filter
The engine air cleaner/filter is in the
engine compartment on the
passenger side of the vehicle. See
Engine Compartment Overview
0231.
When to Inspect the Engine Air
Cleaner/Filter
For intervals on changing and
inspecting the engine air cleaner/
filter, see Maintenance Schedule
0 311.
How to Inspect the Engine Air
Cleaner/Filter
Do not start the engine or have the
engine running with the engine air
cleaner/filter housing open. Before
removing the engine air cleaner/
filter, make sure that the engine air
cleaner/filter housing and nearby
components are free of dirt and
debris. Remove the engine air
cleaner/filter. Lightly tap and shake
the engine air cleaner/filter (away
from the vehicle), to release loose
dust and dirt. Inspect the engine air
cleaner/filter for damage, and replace if damaged. Do not clean
the engine air cleaner/filter or
components with water or
compressed air.
To inspect or replace the engine air
cleaner/filter:
2.5L L4 Engine

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
240 Vehicle Care
3.6L V6 Engine
1. Engine Cooling Fans (Outof View)
2. Coolant Surge Tank and Pressure Cap
{Warning
An underhood electric fan can
start up even when the engine is
not running and can cause injury.
Keep hands, clothing, and tools
away from any underhood
electric fan.
{Warning
Do not touch heater or radiator
hoses, or other engine parts.
They can be very hot and can
burn you. Do not run the engine if
there is a leak; all coolant could
leak out. That could cause an
engine fire and can burn you. Fix
any leak before driving the
vehicle.
Engine Coolant
The cooling system in the vehicle is
filled with DEX-COOL engine
coolant. This coolant needs to be
checked and replaced at
appropriate intervals. See
Maintenance Schedule 0311.
The following explains the cooling
system and how to check and add
coolant when it is low. If there is a
problem with engine overheating,
see Engine Overheating 0243.
What to Use
{Warning
Plain water, or other liquids such
as alcohol, can boil before the
proper coolant mixture will. With
plain water or the wrong mixture,
the engine could get too hot but
there would not be an overheat
warning. The engine could catch
fire and you or others could be
burned.
Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
coolant. If using this mixture,
nothing else needs to be added.
This mixture:
. Gives freezing protection down
to−37 °C (−34 °F), outside
temperature
. Gives boiling protection up to
129 °C (265 °F), engine
temperature
. Protects against rust and
corrosion
. Will not damage aluminum parts

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
Vehicle Care 241
.Helps keep the proper engine
temperature
Caution
Do not use anything other than a
mix of DEX-COOL coolant that
meets GM Standard
GMW3420 and clean, drinkable
water. Anything else can cause
damage to the vehicle’ s engine
cooling system and vehicle, which
would not be covered by the
vehicle warranty.
Never dispose of engine coolant by
putting it in the trash, pouring it on
the ground, or into sewers, streams,
or bodies of water. Have the coolant
changed by an authorized service
center, familiar with legal
requirements regarding used
coolant disposal. This will help
protect the environment and your
health.
Checking Coolant
The vehicle must be on a level
surface when checking the coolant
level.
2.5L L4 Engine Coolant Surge Tank
3.6L V6 Engine CoolantSurge Tank
Check to see if coolant is visible in
the coolant surge tank. If the coolant
inside the coolant surge tank is
boiling, do not do anything else until
it cools down. If coolant is visible
but the coolant level mark is not
visible, add a 50/50 mixture of
clean, drinkable water and
DEX-COOL coolant at the coolant
surge tank to the top rib on the
middle of the tank, but be sure the
cooling system is cool before this is
done. See Engine Overheating
0 243.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
242 Vehicle Care
The coolant surge tank is in the
engine compartment on the driver
side of the vehicle. SeeEngine
Compartment Overview 0231.
How to Add Coolant to the
Coolant Surge Tank
If no problem is found, check to see
if coolant is visible in the coolant
surge tank. If coolant is visible but
the coolant level is not at the
indicated level mark, add a 50/
50 mixture of clean, drinkable water
and DEX-COOL coolant at the
coolant surge tank, but be sure the
cooling system, including the
coolant surge tank pressure cap, is
cool before you do it.
{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,
(Continued)
Warning (Continued)
including the pressure cap, is hot.
Wait for the cooling system and
pressure cap to cool.
{Warning
Plain water, or other liquids such
as alcohol, can boil before the
proper coolant mixture will. With
plain water or the wrong mixture,
the engine could get too hot but
there would not be an overheat
warning. The engine could catch
fire and you or others could be
burned.
{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.
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.
1. Remove the coolant surge tankpressure cap 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 about
one-quarter of a turn. If you
hear a hiss, wait for that to
stop. This will allow any
pressure still left to be vented
out the discharge hose.