ignition BUICK LACROSSE 2018 Workshop Manual

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
182 Driving and Operating
This vehicle is equipped with an
electronic transmission. The shift
lock release button is designed to
prevent shifting out of P (Park) while
the vehicle is running, unless the
ignition is on, the brake pedal is
applied, and the shift lock release
button is pressed.
When the vehicle is stopped, press
ENGINE START/STOP to turn off
the vehicle. The transmission will
shift to P (Park) automatically.
The vehicle will not shift into
P (Park) if it is moving too fast. Stop
the vehicle and shift into P (Park).To shift in and out of P (Park), see
Shifting Into Park
0176 andShifting
out of Park 0177.
R : Use this gear to back up.
If the vehicle is shifted from either
R (Reverse) to D (Drive),
or D (Drive) to R (Reverse) while the
speed is too high, the vehicle will
shift to N (Neutral). Reduce the
vehicle speed and try the shift
again.
To shift into R (Reverse): 1. Bring the vehicle to a complete stop.
2. Press the shift lock release button on the side of the shift
lever.
3. From the center position, move the shift lever forward, and
then to the left.
4. R will illuminate in red.
5. After releasing the shift lever, it will return to the center
position. To shift out of R (Reverse):
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.
At low vehicle speeds, R (Reverse)
can be used to rock the vehicle
back and forth to get out of snow,
ice, or sand without damaging the
transmission. See If the Vehicle Is
Stuck 0166.
N : In this position, the engine does
not connect to the wheels. To restart
the engine when the vehicle is
already moving, use
N (Neutral) only.
{Warning
Shifting into a drive gear while the
engine is running at high speed is
dangerous. Unless your foot is
firmly on the brake pedal, the
vehicle could move very rapidly.
(Continued)

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
188 Driving and Operating
Using ABS
Do not pump the brakes. Just hold
the brake pedal down firmly and let
ABS work. You may hear the ABS
pump or motor operating and feel
the brake pedal pulsate. This is
normal.
Braking in Emergencies
ABS allows you to steer and brake
at the same time. In many
emergencies, steering can help
more than even the very best
braking.
Electric Parking Brake
The Electric Parking Brake (EPB)
can always be activated, even if the
ignition is off. To prevent draining
the battery, avoid repeated cycles of
the EPB when the engine is not
running.
The system has a red parking brake
status light and an amber parking
brake warning light. There are also
parking brake-related Driver
Information Center (DIC) messages.
In case of insufficient electrical
power, the EPB cannot be applied
or released.
Before leaving the vehicle, check
the red parking brake status light to
ensure that the parking brake is
applied.
EPB Apply
To apply the EPB:1. Be sure the vehicle is at a complete stop.
2. Press the EPB switch momentarily.
The red parking brake status light
will flash and then stay on once the
EPB is fully applied. If the red parking brake status light flashes
continuously, then the EPB is only
partially applied or there is a
problem with the EPB. A DIC
message will display. Release the
EPB and try to apply it again. If the
light does not come on, or keeps
flashing, have the vehicle serviced.
Do not drive the vehicle if the red
parking brake status light is flashing.
See your dealer.
If the amber parking brake warning
light is on, press the EPB switch.
Continue to hold the switch until the
red parking brake status light
remains on. If the amber parking
brake warning light is on, see your
dealer.
If the EPB is applied while the
vehicle is moving, the vehicle will
decelerate as long as the switch is
pressed. If the switch is pressed
until the vehicle comes to a stop,
the EPB will remain applied.
The vehicle may automatically apply
the EPB in some situations when
the vehicle is not moving. This is

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
Driving and Operating 189
normal, and is done to periodically
check the correct operation of the
EPB system.
If the EPB fails to apply, block the
rear wheels to prevent vehicle
movement.
EPB Release
To release the EPB:1. Turn the ignition on or to ACC/ ACCESSORY.
2. Apply and hold the brake pedal.
3. Press the EPB switch momentarily.
The EPB is released when the red
parking brake status light is off.
If the amber parking brake warning
light is on, release the EPB by
pressing and holding the EPB
switch. Continue to hold the switch
until the red parking brake status
light is off. If either light stays on
after release is attempted, see your
dealer.
Caution
Driving with the parking brake on
can overheat the brake system
and cause premature wear or
damage to brake system parts.
Make sure that the parking brake
is fully released and the brake
warning light is off before driving.
Automatic EPB Release
The EPB will automatically release if
the vehicle is running, placed into
gear, and an attempt is made to
drive away. Avoid rapid acceleration
when the EPB is applied, to
preserve parking brake lining life.
Brake Assist
The Brake Assist feature is
designed to assist the driver in
stopping or decreasing vehicle
speed in emergency driving
conditions. This feature uses the
stability system hydraulic brake
control module to supplement the
power brake system under
conditions where the driver has quickly and forcefully applied the
brake pedal in an attempt to quickly
stop or slow down the vehicle. The
stability system hydraulic brake
control module increases brake
pressure at each corner of the
vehicle until the ABS activates.
Minor brake pedal pulsation or
pedal movement during this time is
normal and the driver should
continue to apply the brake pedal as
the driving situation dictates. The
Brake Assist feature will
automatically disengage when the
brake pedal is released or brake
pedal pressure is quickly
decreased.
Automatic Vehicle
Hold (AVH)
The Automatic Vehicle Hold (AVH)
feature provides Hill Start Assist
(HSA). This feature will activate
when the vehicle is stopped on a
moderate to steep grade to help
prevent it from rolling in an
unintended direction. After the brake
pedal has been released and before
the accelerator pedal has been
pressed, AVH uses braking

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
Driving and Operating 195
Passing Another Vehicle While
Using Cruise Control
Use the accelerator pedal to
increase the vehicle speed. When
you take your foot off the pedal, the
vehicle will slow down to the
previously set cruise speed. While
pressing the accelerator pedal or
shortly following the release to
override cruise control, briefly
pressing SET−will result in cruise
set to the current vehicle speed.
Using Cruise Control on Hills
How well the cruise control will work
on hills depends upon the vehicle
speed, load, and the steepness of
the hills. When going up steep hills,
you might have to step on the
accelerator pedal to maintain your
speed. When going downhill, you
might have to brake or shift to a
lower gear to keep your speed
down. If the brake pedal is applied,
cruise control will disengage.
Ending Cruise Control
There are four ways to end cruise
control:
. Step lightly on the brake pedal. .
Press*.
. Shift the transmission to
N (Neutral).
. To turn off cruise control,
press
5.
Erasing Speed Memory
The cruise control set speed is
erased from memory if
5is pressed
or the ignition is turned off.
Adaptive Cruise Control
If equipped with Adaptive Cruise
Control (ACC), it allows for selecting
the cruise control set speed and
following gap. Read this entire
section before using this system.
ACC uses a radar sensor to detect
other vehicles. See Radio
Frequency Statement 0335. The
following gap is the following time
(or distance) between your vehicle
and a vehicle detected directly
ahead in your path, moving in the
same direction. If no vehicle is
detected in your path, ACC works
like regular cruise control. If a vehicle is detected in your path,
ACC can speed up the vehicle or
apply limited, moderate braking to
maintain the selected following gap.
To disengage ACC, apply the brake.
If the Traction Control System (TCS)
or StabiliTrak
®electronic stability
control system activates while ACC
is engaged, ACC may automatically
disengage. See Traction Control/
Electronic Stability Control 0190.
When road conditions allow ACC to
be safely used, ACC can be turned
back on. ACC will not engage if the
TCS or StabiliTrak electronic
stability control system is disabled.
{Warning
ACC has limited braking ability
and may not have time to slow
the vehicle down enough to avoid
a collision with another vehicle
you are following. This can occur
when vehicles suddenly slow or
stop ahead, or enter your lane.
Also see “Alerting the Driver” in
this section. Complete attention is
(Continued)

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
200 Driving and Operating
Notification to Resume ACC
ACC will maintain a following gap
behind a detected vehicle and slow
your vehicle to a stop behind that
vehicle.
If the stopped vehicle ahead has
driven away and ACC has not
resumed, the vehicle ahead
indicator will flash as a reminder to
check traffic ahead before
proceeding. In addition, the left and
right sides of the Safety Alert Seat
will pulse three times, or three
beeps will sound. See”Alert Type”
and “Go Notifier” in“Collision/
Detection Systems” underVehicle
Personalization 0133.
When the vehicle ahead drives
away, press RES+ or the
accelerator pedal to resume cruise
control. If stopped for more than
two minutes or if the driver door is
opened and the driver seat belt is
unbuckled, ACC automatically
applies the Electric Parking Brake
(EPB) to hold the vehicle. The
Electric Parking Brake status light will turn on. See
Electric Parking
Brake 0188. To release the EPB,
press the accelerator pedal.
A DIC warning message may
display indicating to shift to P (Park)
before exiting the vehicle.
{Warning
If ACC has stopped the vehicle,
and if ACC is disengaged, turned
off, or canceled, the vehicle will
no longer be held at a stop. The
vehicle can move. When ACC is
holding the vehicle at a stop,
always be prepared to manually
apply the brakes.
{Warning
Leaving the vehicle without
placing it in P (Park) can be
dangerous. Do not leave the
vehicle while it is being held at a
stop by ACC. Always place the
(Continued)
Warning (Continued)
vehicle in P (Park) and turn off
the ignition before leaving the
vehicle.
ACC Override
If using the accelerator pedal while
ACC is active, a DIC warning
message will indicate that automatic
braking will not occur. ACC will
resume operation when the
accelerator pedal is not being
pressed.
{Warning
The ACC will not automatically
apply the brakes if your foot is
resting on the accelerator pedal.
You could crash into a vehicle
ahead of you.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
202 Driving and Operating
Other Vehicle Lane Changes
ACC will not detect a vehicle ahead
until it is completely in the lane. The
brakes may need to be manually
applied.
Do Not Use ACC on Hills and
When Towing a Trailer
Do not use ACC when driving on
steep hills or when towing a trailer.
ACC will not detect a vehicle in thelane while driving on steep hills. The
driver will often need to take over
acceleration and braking on steep
hills, especially when towing a
trailer. If the brakes are applied, the
ACC disengages.
Disengaging ACC
There are three ways to
disengage ACC:
.
Step lightly on the brake pedal.
. Press
*.
. Press
5.
Erasing Speed Memory
The cruise control set speed is
erased from memory if
5is pressed
or if the ignition is turned off. Cleaning the Sensing System
The radar sensor on the front of the
vehicle can become blocked by
snow, ice, dirt, or mud. This area
needs to be cleaned for ACC to
operate properly.
For cleaning instructions, see
“Washing the Vehicle”
under
Exterior Care 0300.
System operation may also be
limited under snow, heavy rain,
or road spray conditions.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
Vehicle Care 255
The vehicle may not be equipped
with all of the fuses, relays, and
features shown.Fuses Usage
1 –
2 –
3 ABS pump
5 AC DC inverter
6 Rear closure
7 Left corner lamp
8 Power windows/ Rearview mirror/
Power seats
9 Engine boost
10 Airbag sensing diagnostic module/
Passenger sensing
module—eAssist
11 DC DC Battery 1
12 Rear window defogger
13 Heated mirrors
14 – Fuses Usage
15 Passive entry/ Passive start
16 Front wipers
17 Passenger power seat
18 ABS valve
19 Driver power seat
21 Sunroof
22 Right corner lamp
23 Auto headlamp leveling
24 –
26 Transmission control module/Ignition
27 Instrument panel/ Ignition
28 Electronic precision shift/Ignition
29 Rear vision camera/ Ventilation
30 Malfunction indicator lamp/Shift solenoid Fuses Usage
32 Canister vent solenoid
33 Front heated seats
34 BSM (eAssist)/Fan control module/
Damping control
module (SADS)
35 Fog lamps
36 Fuel module
38 –
39 –
40 Steering columnn lock
41 –
43 Heated steering wheel
44 Headlamp leveling/ Rear seat ventilation
45 –
46 Engine control module/Ignition
47 –

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
256 Vehicle Care
FusesUsage
48 Engine boost/Left cooling fan
49 DC DC battery 2/AWD
50 –
51 –
52 –
53 –
54 –
55 –
56 –
57 Transmission auxiliary pump
58 TRCM
59 High-beam headlamps
60 Cooling fan
61 –
62 –
63 –
65 A/C HEV Fuses
Usage
67 –
68 –
69 Right HID low-beam headlamps
70 Left HID low-beam headlamps
72 Starter pinion
74 Starter motor
75 Engine control module
76 Powertrain –off
engine
77 –
78 Horn
79 Washer pump
81 Transmission control module/ Engine
control module
82 –
83 Ignition coils
84 Coil Fuses
Usage
85 Engine control module switch 2
86 Engine control module switch 1
87 SAI reaction pump
88 Aeroshutter
89 Headlamp washer
91 –
92 TPIM motor generator unit pump
93 Headlamp leveling
95 SAI reaction solenoid
96 Fuel heater
97 –
99 Coolant pump
Relays Usage
4 AC DC inverter
20 Rear defogger
25 Front wiper control
31 Run/Crank

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
Vehicle Care 269
This sequence will continue upon
subsequent vehicle start-ups as
long as the malfunction exists.
When the malfunction indicator is
illuminated, the system may not be
able to detect or signal low tire
pressure as intended. TPMS
malfunctions may occur for a variety
of reasons, including the installation
of replacement or alternate tires or
wheels on the vehicle that prevent
the TPMS from functioning properly.
Always check the TPMS malfunction
telltale after replacing one or more
tires or wheels on your vehicle to
ensure that the replacement or
alternate tires and wheels allow the
TPMS to continue to function
properly.
SeeTire Pressure Monitor
Operation 0269.
See Radio Frequency Statement
0 335.Tire Pressure Monitor
Operation
This vehicle may have a Tire
Pressure Monitor System (TPMS).
The TPMS is designed to warn the
driver when a low tire pressure
condition exists. TPMS sensors are
mounted onto each tire and wheel
assembly, excluding the spare tire
and wheel assembly. The TPMS
sensors monitor the air pressure in
the tires and transmit the tire
pressure readings to a receiver
located in the vehicle.
When a low tire pressure condition
is detected, the TPMS illuminates
the low tire pressure warning light
located on the instrument cluster.
If the warning light comes on, stop
as soon as possible and inflate the
tires to the recommended pressure shown on the Tire and Loading
Information label. See
Vehicle Load
Limits 0166.
A message to check the pressure in
a specific tire displays in the Driver
Information Center (DIC). The low
tire pressure warning light and the
DIC warning message come on at
each ignition cycle until the tires are
inflated to the correct inflation
pressure. Using the DIC, tire
pressure levels can be viewed. For
additional information and details
about the DIC operation and
displays see Driver Information
Center (DIC) 0126.
The low tire pressure warning light
may come on in cool weather when
the vehicle is first started, and then
turn off as the vehicle is driven. This
could be an early indicator that the
air pressure is getting low and
needs to be inflated to the proper
pressure.
A Tire and Loading Information
label, attached to your vehicle,
shows the size of the original
equipment tires and the correct
inflation pressure for the tires when

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
270 Vehicle Care
they are cold. SeeVehicle Load
Limits 0166, for an example of the
Tire and Loading Information label
and its location. Also see Tire
Pressure 0266.
The TPMS can warn about a low
tire pressure condition but it does
not replace normal tire
maintenance. See Tire Inspection
0 272, Tire Rotation 0272 andTires
0 259.
Caution
Tire sealant materials are not all
the same. A non-approved tire
sealant could damage the TPMS
sensors. TPMS sensor damage
caused by using an incorrect tire
sealant is not covered by the
vehicle warranty. Always use only
the GM approved tire sealant
available through your dealer or
included in the vehicle.
Factory-installed Tire Inflator Kits
use a GM-approved liquid tire
sealant. Using non-approved tire
sealants could damage the TPMS sensors. See
Tire Sealant and
Compressor Kit 0280 for
information regarding the inflator kit
materials and instructions.
TPMS Malfunction Light and
Message
The TPMS will not function properly
if one or more of the TPMS sensors
are missing or inoperable. When the
system detects a malfunction, the
low tire pressure warning light
flashes for about one minute and
then stays on for the remainder of
the ignition cycle. A DIC warning
message also displays. The
malfunction light and DIC warning
message come on at each ignition
cycle until the problem is corrected.
Some of the conditions that can
cause these to come on are:
. One of the road tires has been
replaced with the spare tire. The
spare tire does not have a
TPMS sensor. The malfunction
light and DIC message should
go off after the road tire is
replaced and the sensor
matching process is performed successfully. See
“TPMS Sensor
Matching Process” later in this
section.
. The TPMS sensor matching
process was not done or not
completed successfully after
rotating the tires. The
malfunction light and the DIC
message should go off after
successfully completing the
sensor matching process. See
"TPMS Sensor Matching
Process" later in this section.
. One or more TPMS sensors are
missing or damaged. The
malfunction light and the DIC
message should go off when the
TPMS sensors are installed and
the sensor matching process is
performed successfully. See
your dealer for service.
. Replacement tires or wheels do
not match the original equipment
tires or wheels. Tires and wheels
other than those recommended
could prevent the TPMS from
functioning properly. See Buying
New Tires 0274.