
Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-9803782) -
2017 - crc - 9/7/16
Instruments and Controls 115
Caution
Modifications to the engine,
transmission, exhaust, intake,
or fuel system, or the use of
replacement tires that do not
meet the original tire
specifications, can cause this light
to come on. This could lead to
costly repairs not covered by the
vehicle warranty. This could also
affect the vehicle’s ability to pass
an Emissions Inspection/
Maintenance test. See
Accessories and Modifications
0228.
If the light is flashing : A
malfunction has been detected that
could damage the emission control
system and increase vehicle
emissions. Diagnosis and service
may be required.
To help prevent damage, reduce
vehicle speed and avoid hard
accelerations and uphill grades. If towing a trailer, reduce the
amount of cargo being hauled as
soon as possible.
If the light continues to flash, find a
safe place to park. Turn the vehicle
off and wait at least 10 seconds
before restarting the engine. If the
light is still flashing, follow the
previous guidelines and see your
dealer for service as soon as
possible.
If the light is on steady :
A
malfunction has been detected.
Diagnosis and service may be
required.
Check the following:
. If fuel has been added to the
vehicle using the capless funnel
adapter, make sure that it has
been removed. See “Filling the
Tank with a Portable Gas Can”
under Filling the Tank 0218.
The diagnostic system can
detect if the adapter has been
left installed in the vehicle,
allowing fuel to evaporate into
the atmosphere. A few driving
trips with the adapter removed
may turn off the light. .
Poor fuel quality can cause
inefficient engine operation and
poor driveability, which may go
away once the engine is warmed
up. If this occurs, change the
fuel brand. It may require at
least one full tank of the proper
fuel to turn the light off. See Fuel
0 217.
If the light remains on, see your
dealer.
Emissions Inspection and
Maintenance Programs
If the vehicle requires an Emissions
Inspection/Maintenance test, the
test equipment will likely connect to
the vehicle's Data Link
Connector (DLC).
The DLC is under the instrument
panel to the left of the steering
wheel. Connecting devices that are

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-9803782) -
2017 - crc - 9/7/16
136 Instruments and Controls
Steering System
Messages
STEERING ASSIST IS
REDUCED DRIVE WITH CARE
This message may display if a
problem occurs with the electric
power steering system. If this
message appears, steering effort
may be slightly higher than normal.
The vehicle is still safe to drive. Use
caution while in reduced assist
mode. If this message is persistent
or appears repeatedly, take the
vehicle to your dealer for service.
SeeSteering 0165.
Starting the Vehicle
Messages
PRESS BRAKE TO START
This message is displayed when
attempting to start the vehicle
without first pressing the brake
pedal.
SERVICE KEYLESS START
SYSTEM
This message is displayed if there is
a problem with the pushbutton start
system. Take the vehicle to your
dealer for service.
Tire Messages
SERVICE TIRE MONITOR
SYSTEM
This message displays if there is a
problem with the Tire Pressure
Monitor System (TPMS). See Tire
Pressure Monitor Operation 0264.
TIRE LEARNING ACTIVE
This message displays when the
system is learning new tires. See
Tire Pressure Monitor Operation
0264.
TIRE PRESSURE LOW ADD
AIR TO TIRE
On vehicles with the Tire Pressure
Monitor System (TPMS), this
message displays when the
pressure in one or more of the
vehicle's tires is low. The low tire pressure warning light
will also come on. See
Tire
Pressure Light 0119.
If a tire pressure message displays,
inflate the tires until the tire pressure
is equal to the values shown on the
Tire and Loading Information label.
See Tires 0254, Vehicle Load
Limits 0170, and Tire Pressure
0 261.
More than one tire pressure
message can be received at a time.
The DIC also shows the tire
pressure values. See Driver
Information Center (DIC) 0122.
Transmission Messages
SERVICE TRANSMISSION
There may be a problem with the
transmission. See your dealer.
SERVICE TRANSMISSION
NOW UNABLE TO
SHIFT SOON
The transmission needs service.
Unless the vehicle is serviced, the
transmission will be unable to be

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-9803782) -
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Instruments and Controls 137
shifted out of P (Park) soon. Have
the vehicle serviced as soon as
possible.
SERVICE SHIFTER SEE
OWNER’S MANUAL
The shift lever needs service. Have
the vehicle serviced as soon as
possible. If the vehicle is
automatically shifting into P (Park),
check to see if the P (Park) button
on top of the shifter is stuck. To
operate the vehicle, hold the shift
lever in the desired gear,
R (Reverse) or D (Drive), until
vehicle speed exceeds 15 km/h
(10 mph), then release the shift
lever.
SHIFT DENIED
This message displays when
attempting to shift to a gear not
appropriate for the vehicle speed
and engine revolutions per
minute (rpm).
SHIFT TO PARK
This message displays when the
transmission needs to be shifted to
P (Park). This may appear when
turning the ignition off if the vehicle
is not in P (Park).
TRANSMISSION HOT—IDLE
ENGINE
This message displays and a chime
sounds if the transmission fluid in
the vehicle gets hot. Driving with the
transmission fluid temperature high
can cause damage to the vehicle.
Stop the vehicle and let it idle to
allow the transmission to cool. This
message clears when the fluid
temperature reaches a safe level.
Vehicle Reminder
Messages
REAR SEAT REMINDER LOOK
IN REAR SEAT
This message displays under
certain conditions indicating there
may be an item or passenger in the
rear seat. Check before exiting the
vehicle.
Vehicle Speed Messages
SPEED LIMIT EXCEEDED
This message is displayed when the
vehicle speed is greater than the
speed warning speed. See "Speed
Warning" under Instrument Cluster
0 108.
SPEED LIMIT SET TO XXX
This message is displayed when the
speed warning is set. See "Speed
Warning" under Instrument Cluster
0 108.
Window Messages
OPEN, THEN CLOSE DRIVER/
PASSENGER WINDOW
This message is displayed when the
window needs to be reprogrammed.
If the vehicle's battery has been
discharged or disconnected, you
may need to program each front
window for the express-up feature to
work. See Power Windows 045.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-9803782) -
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Driving and Operating 167
Warning (Continued)
After driving through a large
puddle of water or a car/vehicle
wash, lightly apply the brake
pedal until the brakes work
normally.
Flowing or rushing water creates
strong forces. Driving through
flowing water could cause the
vehicle to be carried away. If this
happens, you and other vehicle
occupants could drown. Do not
ignore police warnings and be
very cautious about trying to drive
through flowing water.
Hydroplaning
Hydroplaning is dangerous. Water
can build up under the vehicle's
tires so they actually ride on the
water. This can happen if the road is
wet enough and you are going fast
enough. When the vehicle is
hydroplaning, it has little or no
contact with the road.There is no hard and fast rule about
hydroplaning. The best advice is to
slow down when the road is wet.
Other Rainy Weather Tips
Besides slowing down, other wet
weather driving tips include:
.
Allow extra following distance.
. Pass with caution.
. Keep windshield wiping
equipment in good shape.
. Keep the windshield washer fluid
reservoir filled.
. Have good tires with proper
tread depth. See Tires0254.
. Turn off cruise control.
Hill and Mountain Roads
Driving on steep hills or through
mountains is different than driving
on flat or rolling terrain. Tips include:
.
Keep the vehicle serviced and in
good shape.
. Check all fluid levels and brakes,
tires, cooling system, and
transmission. .
Shift to a lower gear when going
down steep or long hills.
{Warning
Using the brakes to slow the
vehicle on a long downhill slope
can cause brake overheating, can
reduce brake performance, and
could result in a loss of braking.
Shift the transmission to a lower
gear to let the engine assist the
brakes on a steep downhill slope.
{Warning
Coasting downhill in N (Neutral)
or with the ignition off is
dangerous. This can cause
overheating of the brakes and
loss of steering. Always have the
engine running and the vehicle
in gear.
. Drive at speeds that keep the
vehicle in its own lane. Do not
swing wide or cross the
center line.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-9803782) -
2017 - crc - 9/7/16
Driving and Operating 175
engine starts. SeeStarting the
Engine 0175. The ignition will then
remain in ON/RUN.
Service Only Mode
This power mode is available for
service and diagnostics, and Car
Wash Mode. See Automatic
Transmission 0181. Service Only
Mode is also available to verify the
proper operation of the malfunction
indicator lamp as may be required
for emission inspection purposes.
With the vehicle off, and the brake
pedal not applied, pressing and
holding ENGINE START/STOP for
more than five seconds will place
the vehicle in Service Only Mode.
The instruments and audio systems
will operate as they do in ON/RUN,
but the vehicle will not be able to be
driven. The engine will not start in
Service Only Mode. Press ENGINE
START/STOP again to turn the
vehicle off.Starting the Engine
Place the transmission in P (Park) or
N (Neutral). To restart the engine
when the vehicle is already moving,
use N (Neutral).
Caution
Do not try to shift to P (Park) if the
vehicle is moving. If you do, you
could damage the transmission.
Shift to P (Park) only when the
vehicle is stopped.
Caution
If you add electrical parts or
accessories, you could change
the way the engine operates. Any
resulting damage would not be
covered by the vehicle warranty.
See Add-On Electrical Equipment
0 225. To start the vehicle:
1. With the Keyless Access system, the RKE transmitter
must be in the vehicle. Press
ENGINE START/STOP with the
brake pedal applied. When the
engine begins cranking, let go
of the button. The idle speed
will go down as the engine
warms up. Do not race the
engine immediately after
starting it.
If the RKE transmitter is not in
the vehicle, if there is
interference, or if the RKE
battery is low, a Driver
Information Center (DIC)
message will display.
See Key and Lock Messages
0 132 andRemote Keyless
Entry (RKE) System Operation
0 27.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-9803782) -
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184 Driving and Operating
2. After releasing the shift lever, itwill return to the center
position.
To shift out of N (Neutral): 1. Bring the vehicle to a complete stop.
2. Shift to the desired gear.
3. After releasing the shift lever, it will return to the center
position.
Car Wash Mode (Engine Off)
To place the vehicle in N (Neutral)
with the engine off: 1. Put the ignition in OFF.
2. Put the ignition in Service Only Mode. See Ignition Positions
0 173.
3. Open the door while pressing the brake, and then shift to
N (Neutral).
4. The indicator should now show N. If it does not, repeat the
procedure.
5. When N (Neutral) is no longer needed, shift into P (Park) and
turn the ignition to OFF. Car Wash Mode (Engine On)
To place the vehicle in N (Neutral)
with the engine running:
1. Open the door while pressing the brake, then shift to
N (Neutral).
2. The indicator should now show N. If it does not, select
N (Neutral) again.
3. Shift into P (Park) upon returning to the vehicle.
D : This position is for normal
driving. It provides the best fuel
economy. If you need more power
for passing, and you are:
. Going less than 35 mph
(55 km/h), push the accelerator
pedal about halfway down.
. Going about 35 mph (55 km/h) or
more, push the accelerator all
the way down.
The transmission will shift down
to a lower gear and have more
power. To shift into D (Drive):
1. Bring the vehicle to a complete stop.
2. From the center position, move the shift lever back. If the
vehicle is in P (Park) press the
shift lever unlock button while
moving the shift lever back. D
is illuminated in red.
3. After releasing the shift lever, it will return to the center
position.
To shift out of D (Drive):
1. Bring the vehicle to a complete stop.
2. Shift to the desired gear.
3. After releasing the shift lever, it will return to the center
position.
Downshifting the transmission in
slippery road conditions could result
in skidding. See “Skidding”under
Loss of Control 0166.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-9803782) -
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Driving and Operating 223
Maintenance when Trailer
Towing
The vehicle needs service more
often when pulling a trailer. See
Maintenance Schedule0297.
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, 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 it has
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
0 313.
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 0170.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-9803782) -
2017 - crc - 9/7/16
226 Vehicle Care
Vehicle Care
General Information
General Information . . . . . . . . . . 227
California Proposition65 Warning . . . . . . . . . . . . . . . . . 227
California Perchlorate Materials Requirements . . . . . 227
Accessories and Modifications . . . . . . . . . . . . . . . . 228
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 228
Hood . . . . . . . . . . . . . . . . . . . . . . . . . 229
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . 230
Engine Oil . . . . . . . . . . . . . . . . . . . . 231
Engine Oil Life System . . . . . . . 233
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . 234
Engine Air Cleaner/Filter . . . . . . 235
Cooling System . . . . . . . . . . . . . . 236
Engine Coolant . . . . . . . . . . . . . . . 236
Engine Overheating . . . . . . . . . . 239
Overheated Engine Protection Operating Mode . . . . . . . . . . . . . 240
Washer Fluid . . . . . . . . . . . . . . . . . 241
Brakes . . . . . . . . . . . . . . . . . . . . . . . 242
Brake Fluid . . . . . . . . . . . . . . . . . . . 242 Battery - North America . . . . . . 243
All-Wheel Drive . . . . . . . . . . . . . . . 244
Starter Switch Check . . . . . . . . . 244
Park Brake and P (Park)
Mechanism Check . . . . . . . . . . 245
Wiper Blade Replacement . . . . 245
Windshield Replacement . . . . . 246
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . 246
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . 246
High Intensity Discharge (HID) Lighting . . . . . . . . . . . . . . . . . . . . . 246
LED Lighting . . . . . . . . . . . . . . . . . 247
Taillamps, Turn Signal, Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . . . 247
License Plate Lamp . . . . . . . . . . 247
Replacement Bulbs . . . . . . . . . . . 248
Electrical System
Electrical System Overload . . . 248
Fuses and Circuit Breakers . . . 249
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 249
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 252
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 254 All-Season Tires . . . . . . . . . . . . . . 255
Winter Tires . . . . . . . . . . . . . . . . . . 255
Tire Sidewall Labeling . . . . . . . . 256
Tire Designations . . . . . . . . . . . . . 258
Tire Terminology and
Definitions . . . . . . . . . . . . . . . . . . 259
Tire Pressure . . . . . . . . . . . . . . . . . 261
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . 262
Tire Pressure Monitor System . . . . . . . . . . . . . . . . . . . . . . 263
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . . . 264
Tire Inspection . . . . . . . . . . . . . . . . 267
Tire Rotation . . . . . . . . . . . . . . . . . 267
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . 268
Buying New Tires . . . . . . . . . . . . . 269
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . . . . 270
Uniform Tire Quality Grading . . . . . . . . . . . . . . . . . . . . . 271
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . . . 272
Wheel Replacement . . . . . . . . . . 272
Tire Chains . . . . . . . . . . . . . . . . . . . 273
If a Tire Goes Flat . . . . . . . . . . . . 274
Tire Changing . . . . . . . . . . . . . . . . 275
Compact Spare Tire . . . . . . . . . . 280