Page 262 of 374

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-12032549) -
2019 - crc - 8/20/18
Vehicle Care 261
Headlamp Wiring
An electrical overload may cause
the lamps to go on and off, or in
some cases to remain off. Have the
headlamp wiring checked right away
if the lamps go on and off or
remain off.
Windshield Wipers
If the wiper motor overheats due to
heavy snow or ice, the windshield
wipers will stop until the motor cools
and will then restart.
Although the circuit is protected
from electrical overload, overload
due to heavy snow or ice may
cause wiper linkage damage.
Always clear ice and heavy snow
from the windshield before using the
windshield wipers.
If the overload is caused by an
electrical problem and not snow or
ice, be sure to get it fixed.
Fuses and Circuit
Breakers
The wiring circuits in the vehicle are
protected from short circuits by a
combination of fuses and circuit
breakers. This greatly reduces the
chance of damage caused by
electrical problems.
{Danger
Fuses and circuit breakers are
marked with their ampere rating.
Do not exceed the
specified amperage rating when
replacing fuses and circuit
breakers. Use of an oversized
fuse or circuit breaker can result
in a vehicle fire. You and others
could be seriously injured or
killed.
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.
To identify and check fuses, circuit
breakers, and relays, see
Engine
Compartment Fuse Block 0261 and
Instrument Panel Fuse Block 0265.
Engine Compartment
Fuse Block
To remove the fuse block cover,
squeeze the three retaining clips on
the cover and lift it straight up.
Page 263 of 374
Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-12032549) -
2019 - crc - 8/20/18
262 Vehicle Care
Caution
Spilling liquid on any electrical
component on the vehicle may
damage it. Always keep the
covers on any electrical
component.
The vehicle may not be equipped
with all of the fuses, relays, and
features shown.Fuses Usage
1 –
2 –
3 Antilock brake system pump
5 – Fuses Usage
6 Rear closure
7 Left corner lamp
8 Power windows/ Rearview mirror/
Power seats
9 Electric brake boost/ Pedestrian alert
Page 265 of 374
Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-12032549) -
2019 - crc - 8/20/18
264 Vehicle Care
FusesUsage
56 –
57 Transmission auxiliary pump
58 Transmission range control module
59 High-beam headlamps
60 Cooling fan
61 –
62 –
63 –
65 Air conditioning (HEV)
67 –
68 –
69 Right HID low-beam headlamps
70 Left HID low-beam headlamps
72 Starter pinion
74 Starter motor Fuses
Usage
75 Engine control module
76 Powertrain –off
engine
77 –
78 Horn
79 Washer pump
81 Transmission control module/Engine
control module
82 –
83 Ignition coil –odd
84 Ignition coil –even
85 Shunt
86 Shunt
87 –
88 Aeroshutter
89 Headlamp washer
91 – Fuses
Usage
92 Traction power inverter module/
Motor generator unit
coolant motor
93 Headlamp leveling
95 –
96 –
97 –
99 Coolant pump
Relays Usage
4 –
20 Rear defogger
25 Front wiper control
31 Run/Crank
37 Front wiper speed
42 Transmission auxiliary pump
64 Air conditioning control
66 Powertrain
Page 266 of 374
Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-12032549) -
2019 - crc - 8/20/18
Vehicle Care 265
RelaysUsage
71 HID low-beam headlamps
73 Starter motor
80 Starter pinion
90 –
94 Headlamp washer
98 –
Instrument Panel Fuse
Block
The instrument panel fuse block is
in the instrument panel, on the
driver side of the vehicle. To operate
the fuses, open the fuse panel by
pulling down at the top.
Pull the panel toward you to release
it from the hinges.
Page 267 of 374
Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-12032549) -
2019 - crc - 8/20/18
266 Vehicle Care
The vehicle may not be equipped
with all of the fuses, relays, and
features shown.Fuses Usage
F1 Left window
F2 Right window
F3 – Fuses
Usage
F4 Heating ventilation & air conditioning
blower motor
F5 Body control module 2
F6 Electric steering column
F7 – Fuses
Usage
F8 Body control module 3
F9 Engine control module/Battery
F10 Body control module 2 (stop/start)
F11 –
F12 –
F13 –
F14 –
F15 Transmission control module (stop/start)
F16 Amplifier
F17 –
F18 Body control module 7
F19 –
F20 Body control module 1
F21 Body control module 4
Page 268 of 374
Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-12032549) -
2019 - crc - 8/20/18
Vehicle Care 267
FusesUsage
F22 Body control module 6
F23 Electric steering column lock
F24 Airbag sensing diagnostic module/
Passenger sensing
module
F25 Data link connector
F26 –
F27 AC DC inverter
F28 HID headlamps
F29 Body control module 8
F30 Overhead console
F31 Steering wheel control
F32 –
F33 Heating, ventilation & air conditioning
F34 Communication gateway module Fuses
Usage
F35 Integrated chassis control module
F36 Charger
F37 Auxiliary power outlet/Cigar lighter
F38 OnStar
F39 Display
F40 Obstacle detection
F41 Body control module 1 (stop/start)
F42 Radio
F43 Rear accessory power outlet
F44 Front accessory power outlet
Relays Usage
K1 –
K2 Retained accessory power
K3 –
K4 – Relays
Usage
K5 Logistics
Page 351 of 374

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-12032549) -
2019 - crc - 8/20/18
350 OnStar
Press=to:
. Open the OnStar app on the
infotainment display. See the
infotainment manual for
information on how to use the
OnStar app.
Or
. Make a call, end a call,
or answer an incoming call.
. Give OnStar Hands-Free Calling
voice commands.
. Give OnStar Turn-by-Turn
Navigation voice commands.
. Obtain and customize the Wi-Fi
hotspot name or SSID and
password, if equipped.
Press
Qto connect to an
Advisor to:
. Verify account information or
update contact information.
. Get driving directions.
. Receive a Diagnostic check of
the vehicle's key operating
systems.
. Receive Roadside Assistance. .
Manage Wi-Fi Settings,
if equipped.
Press
>to get a priority connection
to an OnStar Advisor available
24/7 to:
. Get help for an emergency.
. Be a Good Samaritan or
respond to an AMBER Alert.
. Get assistance in severe
weather or other crisis situations
and find evacuation routes.
OnStar Services
Emergency
Emergency Services require an
active safety and security plan. With
Automatic Crash Response, built-in
sensors can automatically alert a
specially trained OnStar Advisor
who is immediately connected in to
the vehicle to help.
Press
>for a priority connection to
an OnStar Advisor who can contact
emergency service providers, direct
them to your exact location, and
relay important information.
With OnStar Crisis Assist, specially
trained Advisors are available
24 hours a day, 7 days a week, to
provide a central point of contact,
assistance, and information during a
crisis.
With Roadside Assistance, Advisors
can locate a nearby service provider
to help with a flat tire, a battery
jump, or an empty gas tank.