ignition BUICK LACROSSE 2015 Repair Manual

Black plate (1,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Vehicle Care 10-1
Vehicle Care
General Information
General Information . . . . . . . . . . 10-2
California Proposition65 Warning . . . . . . . . . . . . . . . . . 10-3
California Perchlorate Materials Requirements . . . . 10-3
Accessories and Modifications . . . . . . . . . . . . . . . 10-3
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 10-4
Hood . . . . . . . . . . . . . . . . . . . . . . . . 10-5
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . 10-6
Engine Oil . . . . . . . . . . . . . . . . . . 10-11
Engine Oil Life System . . . . . 10-13
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . 10-15
Engine Air Cleaner/Filter . . . . 10-15
Cooling System . . . . . . . . . . . . 10-17
Engine Coolant . . . . . . . . . . . . . 10-19
Engine Overheating . . . . . . . . 10-21
Overheated Engine Protection
Operating Mode . . . . . . . . . . . 10-23 Power Steering Fluid (2.4L
L4 Engine and 3.6L
V6 Engine with FWD) . . . . . 10-23
Power Steering Fluid (3.6L V6 Engine with AWD) . . . . . 10-23
Washer Fluid . . . . . . . . . . . . . . . 10-24
Brakes . . . . . . . . . . . . . . . . . . . . . 10-25
Brake Fluid . . . . . . . . . . . . . . . . . 10-26
Battery . . . . . . . . . . . . . . . . . . . . . 10-27
All-Wheel Drive . . . . . . . . . . . . . 10-28
Starter Switch Check . . . . . . . 10-28
Automatic Transmission Shift Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . 10-29
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . 10-29
Park Brake and P (Park) Mechanism Check . . . . . . . . 10-29
Wiper Blade Replacement . . . . . . . . . . . . . . 10-30
Windshield Replacement . . . 10-30
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . 10-31
Bulb Replacement
Bulb Replacement . . . . . . . . . . 10-31
Halogen Bulbs . . . . . . . . . . . . . . 10-31 High Intensity Discharge
(HID) Lighting . . . . . . . . . . . . . 10-31
LED Lighting . . . . . . . . . . . . . . . 10-31
Headlamps, Front Turn Signal and Parking
Lamps . . . . . . . . . . . . . . . . . . . . 10-32
Taillamps, Turn Signal, Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . 10-33
License Plate Lamp . . . . . . . . 10-33
Replacement Bulbs . . . . . . . . . 10-34
Electrical System
High Voltage Devices and Wiring . . . . . . . . . . . . . . . . . . . . . 10-34
Electrical System Overload . . . . . . . . . . . . . . . . . . 10-35
Fuses and Circuit Breakers . . . . . . . . . . . . . . . . . . 10-35
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-36
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-40
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . 10-42
All-Season Tires . . . . . . . . . . . . 10-43
Winter Tires . . . . . . . . . . . . . . . . 10-43
Summer Tires . . . . . . . . . . . . . . 10-43

Black plate (29,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Vehicle Care 10-29
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. Apply the parking brake. 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.
Ignition Transmission
Lock Check
If equipped with a key type ignition,
while parked and with the parking
brake set, try to turn the ignition to
LOCK/OFF in each shift lever
position.
.The ignition should turn to
LOCK/OFF only when the shift
lever is in P (Park).
.The ignition key should come
out only in LOCK/OFF.
Contact your dealer if service is
required.
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.

Black plate (37,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Vehicle Care 10-37
J-CaseFuses Usage
25 Rear Heated Seats
26 Antilock Brake System Pump
27 Electric Parking Brake
28 Rear Window Defogger
41 Brake Vacuum Pump
42 Cooling Fan K2
43 Not Used
44 Transmission Auxiliary Oil Pump
(eAssist)
45 Cooling Fan K1
59 AIR Pump Mini Fuses Usage
1 Transmission Control Module —
Battery
2 Engine Control Module Battery
3 Air Conditioning Compressor Clutch
5 Engine Control Module Run/Crank
7 Long Range Radar/ Front Camera
8 Ignition Coils –Even
(Six Cylinder
Engine), Ignition
Coils –All (Four
Cylinder Engine)
9 Ignition Coils –Odd
(Six Cylinder
Engine) Mini Fuses Usage
10 Engine Control Module–Switched
Battery (from Engine
Control Module
Relay)
11 Six Cylinder Engine: Post Catalytic
Converter Oxygen
Sensor Heater,
Mass Air Flow
Sensor, FlexFuel
Sensor, Secondary
Air Induction
Solenoid
13 Crank for Transmission
Control Module/Fuel
Pump Power/
Chassis Control
Module (eAssist)

Black plate (41,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Vehicle Care 10-41
FusesUsage
9 Body Control Module 4
10 Body Control Module 8
(J-Case Fuse)
11 Front Heater Ventilation Air
Conditioning/Blower
(J-Case Fuse)
12 Passenger Seat (Circuit Breaker)
13 Driver Seat (Circuit Breaker)
14 Diagnostic Link Connector
15 Airbag/Automatic Occupant Sensing
16 Trunk
17 Heater Ventilation Air Conditioning
Controller Fuses
Usage
18 Pre-Fuse for Fuses 4 and 5
19 Center Stack Displays, Head-Up
Display, Right
Steering Wheel
Control Switch, Rear
Seat Infotainment
Display (eAssist),
HVAC Center Stack
Displays
20 Rear Seat Entertainment
Display/Rear Seat
Audio
21 Instrument Cluster
22 Discrete Logic Ignition Switch
23 Body Control Module 3
24 Body Control Module 2 Fuses
Usage
25 Rear Heater Ventilation Air
Conditioning/Blower
26 AC/DC Inverter
Relays Usage
R1 Trunk Relay
R2 Not Used
R3 Power Outlet Relay

Black plate (53,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Vehicle Care 10-53
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 transmits 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. SeeVehicle Load
Limits on page 9-10.
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) on page 5-28.
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
they are cold. See Vehicle Load
Limits on page 9-10, for an example
of the Tire and Loading Information
label and its location. Also see Tire
Pressure on page 10-50. The TPMS can warn about a low
tire pressure condition but it does
not replace normal tire
maintenance. See
Tire Inspection
on page 10-56, Tire Rotation on
page 10-56 andTires on
page 10-42.
{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.
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

Black plate (54,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
10-54 Vehicle Care
low tire 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 on page 10-58.
.Operating electronic devices or
being near facilities using radio
wave frequencies similar to the
TPMS could cause the TPMS
sensors to malfunction.
If the TPMS is not functioning
properly it cannot detect or signal a
low tire condition. See your dealer for service if the TPMS malfunction
light and DIC message comes on
and stays on.
TPMS Sensor Matching
Process
Each TPMS sensor has a unique
identification code. The identification
code needs to be matched to a new
tire/wheel position after rotating the
vehicle’s tires or replacing one or
more of the TPMS sensors. The
TPMS sensor matching process
should also be performed after
replacing a spare tire with a road
tire containing the TPMS sensor.
The malfunction light and the DIC
message should go off at the next
ignition cycle. The sensors are
matched to the tire/wheel positions,
using a TPMS relearn tool, in the
following order: driver side front tire,
passenger side front tire, passenger
side rear tire, and driver side rear.
See your dealer for service or to
purchase a relearn tool. A TPMS
relearn tool can also be purchased.
See Tire Pressure Monitor Sensor

Black plate (55,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Vehicle Care 10-55
Activation Tool at
www.gmtoolsandequipment.com or
call 1-800-GM TOOLS
(1-800-468-6657).
There are two minutes to match the
first tire/wheel position, and
five minutes overall to match all four
tire/wheel positions. If it takes
longer, the matching process stops
and must be restarted.
The TPMS sensor matching
process is:
1. Set the parking brake.
2. Turn the ignition to ON/RUN withthe engine off or place the
vehicle power mode in ON/RUN/
START. See Ignition Positions
(Key Access) on page 9-15 or
Ignition Positions (Keyless
Access) on page 9-16.
3. Make sure the Tire Pressure info page option is turned on. The
info pages on the DIC can be
turned on and off through the Settings menu. See
Driver
Information Center (DIC) on
page 5-28.
4. Use the DIC controls on the right side of the steering wheel to
scroll to the Tire Pressure
screen under the DIC info page.
5. Press and hold the
V(Set/
Reset) button located in the
center of the DIC controls.
The horn sounds twice to signal
the receiver is in relearn mode
and the TIRE LEARNING
ACTIVE message displays on
the DIC screen.
6. Start with the driver side front tire.
7. Place the relearn tool against the tire sidewall, near the valve
stem. Then press the button to
activate the TPMS sensor.
A horn chirp confirms that the
sensor identification code has
been matched to this tire and
wheel position. 8. Proceed to the passenger side
front tire, and repeat the
procedure in Step 7.
9. Proceed to the passenger side rear tire, and repeat the
procedure in Step 7.
10. Proceed to the driver side rear tire, and repeat the procedure
in Step 7. The horn sounds two
times to indicate the sensor
identification code has been
matched to the driver side rear
tire, and the TPMS sensor
matching process is no longer
active. The TIRE LEARNING
ACTIVE message on the DIC
display screen goes off.
11. Turn the ignition to LOCK/OFF or press STOP to turn the
ignition off.
12. Set all four tires to the recommended air pressure
level as indicated on the Tire
and Loading Information label.

Black plate (78,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
10-78 Vehicle Care
{Caution
When the compact spare is
installed, do not take the vehicle
through an automatic car wash
with guide rails. The compact
spare can get caught on the rails
which can damage the tire, wheel,
and other parts of the vehicle.
Do not use the compact spare on
other vehicles.
Do not mix the compact spare tire or
wheel with other wheels or tires.
They will not fit. Keep the spare tire
and its wheel together.
{Caution
Tire chains will not fit the compact
spare. Using them can damage
the vehicle and the chains. Do not
use tire chains on the compact
spare.
Jump Starting
Jump Starting (On-board
with eAssist Only)
If the vehicle fails to crank, it may
be jump started by using the eAssist
battery to charge the 12-volt battery.
Use the following procedure to
activate the on-board jump start
using the DIC controls.
DIC Buttons
The vehicle may be equipped with
an ignition key or an electronic
keyless ignition with pushbutton
start.
Key Access
Place the ignition key in the ON/
RUN position and proceed as
follows:
1. Press
Sthen scrollyorz
until the Settings menu displays.
2. Press
Vto enter the
Settings menu.

Black plate (81,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Vehicle Care 10-81
mounting bolt. Connect to a spot as
far away from the discharged
battery as possible.
1. Check the other vehicle. It musthave 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 on
page 9-24.
{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 to LOCK/OFF and switch 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.

Black plate (84,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
10-84 Vehicle Care
Dolly Towing from the Front
(Front-Wheel Drive)
Vehicles with front-wheel drive can
be dolly towed from the front.
Use the following procedure to dolly
tow the vehicle from the front:
1. Attach the dolly to the towvehicle following the dolly
manufacturer instructions.
2. Drive the front wheels onto the dolly.
3. Shift the transmission to P (Park). 4. Firmly set the parking brake.
5. Use an adequate clamping
device designed for towing to
ensure that the front wheels are
locked into the straight-ahead
position.
6. Secure the vehicle to the dolly following the manufacturer
instructions.
7. Release the parking brake only after the vehicle being towed is
firmly attached to the towing
vehicle.
8. Turn the ignition to OFF.
Dolly Towing from the Front
(All-Wheel Drive)
Vehicles with all-wheel drive cannot
be dolly towed.