2012 BUICK LACROSSE heater

Black plate (15,1)Buick LaCrosse Owner Manual - 2012
Vehicle Care 10-15
Cooling System
The cooling system allows the
engine to maintain the correct
working temperature.
When it is safe to lift the hood:
2.4L L4 Engine
A. Engine Cooling Fans (Outof View)
B. Coolant Surge Tank and Pressure Cap 3.6L V6 Engine
A. Engine Cooling Fans (Out
of View)
B. Coolant Surge Tank and Pressure Cap
{WARNING
An electric engine cooling fan
under the hood 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
Heater and radiator hoses, and
other engine parts, can be very
hot. Do not touch them. If you do,
you can be burned.
Do not run the engine if there is a
leak. If you run the engine, it
could lose all coolant. That could
cause an engine fire, and you
could be burned. Get any leak
fixed before you drive the vehicle.
Notice: Using coolant other than
DEX-COOL
®can cause premature
engine, heater core, or radiator
corrosion. In addition, the engine
coolant could require changing
sooner. Any repairs would not be
covered by the vehicle warranty.
Always use DEX-COOL
(silicate-free) coolant in the
vehicle.

Black plate (17,1)Buick LaCrosse Owner Manual - 2012
Vehicle Care 10-17
Notice:If an improper coolant
mixture is used, the engine could
overheat and be badly damaged.
The repair cost would not be
covered by the vehicle warranty.
Too much deionized water or
clean, drinkable water in the
mixture can freeze and crack the
engine, radiator, heater core, and
other parts.
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.
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 is not at or above the mark
pointed to, add a 50/50 mixture of
deionized water or clean drinkable
water and DEX-COOL coolant.
Be sure the cooling system is cool
before this is done. If no coolant is visible in the coolant
surge tank, add coolant as follows:
How to Add Coolant to the
Coolant Surge Tank
{WARNING
You can be burned if you spill
coolant on hot engine parts.
Coolant contains ethylene glycol
and it will burn if the engine parts
are hot enough. Do not spill
coolant on a hot engine.
Notice: This vehicle has a
specific coolant fill procedure.
Failure to follow this procedure
could cause the engine to
overheat and be severely
damaged.

Black plate (20,1)Buick LaCrosse Owner Manual - 2012
10-20 Vehicle Care
If Steam Is Coming from the
Engine Compartment
SeeOverheated Engine Protection
Operating Mode on page 10‑21 for
information on driving to a safe
place in an emergency.
If No Steam Is Coming from
the Engine Compartment
If an engine overheat warning is
displayed but no steam can be seen
or heard, the problem might not be
too serious. Sometimes the engine
can get a little too hot when the
vehicle:
.Climbs a long hill on a hot day.
.Stops after high-speed driving.
.Idles for long periods in traffic.
.Tows a trailer. If the overheat warning displays with
no sign of steam:
1. Turn the air conditioning off.
2. Turn the heater on to the highest
temperature and to the highest
fan speed. Open the windows as
necessary.
3. In heavy traffic, let the engine idle in N (Neutral) while stopped.
If it is safe to do so, pull off the
road, shift to P (Park) or
N (Neutral), and let the
engine idle.
2.4L L4 Engine
If the engine coolant temperature
warning light no longer displays, the
vehicle can be driven. Continue to
drive the vehicle slowly for about
10 minutes. Keep a safe vehicle
distance from the vehicle in front.
If the warning does not come back
on, continue to drive normally. 3.6L V6 Engine
If the temperature overheat gauge is
no longer in the overheat zone or an
engine coolant temperature warning
light no longer displays, the vehicle
can be driven. Continue to drive the
vehicle slowly for about 10 minutes.
Keep a safe vehicle distance from
the vehicle in front. If the warning
does not come back on, continue to
drive normally.
If the warning continues, pull over,
stop, and park the vehicle
right away.
If there is no sign of steam, idle the
engine for three minutes while
parked. If the warning is still
displayed, turn off the engine until it
cools down. Also, see
Overheated
Engine Protection Operating Mode
on page 10‑21.

Black plate (40,1)Buick LaCrosse Owner Manual - 2012
10-40 Vehicle Care
Mini Fuses Usage1 Transmission
Control
Module
—Battery
2 Engine Control
Module Battery
3 Air Conditioning
Compressor Clutch
5 Engine Control
Module Run/Crank
8 Ignition
Coils
—Even (Six
Cylinder Engine),
Ignition Coils —All
(Four Cylinder
Engine
9 Ignition Coils
—Odd
(Six Cylinder
Engine)
10 Engine Control
Module
—Switched
Battery (from Engine
Control Module
Relay) Mini Fuses Usage
11 Six Cylinder Engine:
Post Catalytic
Converter Oxygen
Sensor Heater,
Mass Air Flow
Sensor, Flex Fuel
Sensor
13 Run/Crank for
Transmission
Control Module and
Fuel System Control
Module
14 Cabin Heater
Coolant Pump
(eAssist)
15 Motor Generator
Unit Coolant Pump
(eAssist)
16 Run/Crank for
eAssist Power
Inverter Module
17 Airbag
Module
—Run/
Crank Mini Fuses Usage
18 Vented Seats
(eAssist)
23 Variable Effort
Steering
(if equipped) or
eAssist Power
Inverter Module
29 Power Lumbar, Left
30 Power Lumbar,
Right or Power Pack
Cooling Fan
(eAssist)
31 Passive Entry/
Passive Start
Module
—Battery 1
(eAssist)
32 Body Control
Module 6
33 Heated
Seat
—Front
34 Antilock Brake
System Valves
35 Amplifier

Black plate (41,1)Buick LaCrosse Owner Manual - 2012
Vehicle Care 10-41
Mini Fuses Usage36 Adaptive Forward
Lighting (AFL)
Motors
—Battery
37 Right High Beam
38 Left High Beam
46 Cooling Fan Relay
47 Six Cylinder Engine:
Pre Catalytic
Converter Oxygen
Sensor Heater,
Canister Purge
Solenoid. Four
Cylinder Engine: Pre
and Post Catalytic
Converter Oxygen
Sensor Heaters,
Canister Purge
Solenoid, Mass Air
Flow Sensor.
48 Fog Lamps
49 Right High Intensity
Discharge
Headlamp Mini Fuses Usage
50 Left High Intensity
Discharge
Headlamp
51 Horn
52 Cluster Run/Crank
53 Run/Crank for Inside
Rearview Mirror,
Rear Vision Camera
54 Run/Crank for:
Heating, Ventilation
and Air Conditioning
55 Outside Rearview
Mirror, Universal
Garage Door
Opener, Front
Window Switches
56 Windshield Washer
60 Heated Mirror
62 Canister Vent
64 Adaptive Forward
Lighting (AFL)
Module
—Battery Mini Fuses Usage
65 Not Used
66 AIR Solenoid
(eAssist)
67 Fuel System Control
Module
69 Regulated Voltage
Control Sensor
70 Ultrasonic Parking
Assist/Side
Blind Zone
Mini Relays Usage 7 Engine Control
Module
9 Cooling Fan
13 Cooling Fan
15 Run/Crank
16 AIR Pump
17 Rear Window
Defogger

Black plate (42,1)Buick LaCrosse Owner Manual - 2012
10-42 Vehicle Care
Micro
Relays Usage
1 Air Conditioning
Compressor Clutch
2 Starter
4 Wiper Speed
5 Wiper Control
6 Cabin Heater
Coolant Pump
(eAssist)
10 Cooling Fan
14 Headlamp
Low Beam
Ultra Micro Relays Usage
11 Transmission
Auxiliary Oil Pump
(eAssist)Instrument Panel Fuse
Block
The instrument panel fuse block is
located in the instrument panel, on
the driver side of the vehicle. To
access the fuses, open the fuse
panel door by pulling down at
the top.
Press in on the sides of the door to
release it from the instrument panel.
Pull the door toward you to release
it from the hinge.

Black plate (43,1)Buick LaCrosse Owner Manual - 2012
Vehicle Care 10-43
Instrument Panel Fuse Block
The vehicle may not be equipped
with all of the fuses, relays, and
features shown. Fuses Usage
1 Steering Wheel
Controls Backlight
2 Body Control
Module 7
3 Body Control
Module 5
4 Radio
5 OnStar
6 Power Outlet 1
7 Power Outlet 2
8 Body Control
Module 1
9 Body Control
Module 4
10 Body Control
Module 8
(J‐Case Fuse) Fuses Usage
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
16 Trunk
17 Heater Ventilation
Air Conditioning
Controller
18 Pre‐Fuse for Fuses
4 and 5

Black plate (44,1)Buick LaCrosse Owner Manual - 2012
10-44 Vehicle Care
FusesUsage
19 Infotainment and
Center Stack
Displays, Head‐Up
Display, Preferred
Device Interface
Module, Rear Seat
Infotainment
(eAssist)
20 Automatic Occupant
Sensing
21 Instrument Panel
Cluster
22 Discrete Logic
Ignition Switch Fuses
Usage
23 Body Control
Module 3
24 Body Control
Module 2
25 Rear Heater
Ventilation Air
Conditioning/Blower
26 AC/DC Inverter
Relays Usage
R1 Trunk Relay
R2 Not Used
R3 Power Outlet RelayRear Compartment Fuse
Block
The rear compartment fuse block is
located on the left side of the trunk
behind a cover. Vehicles with
eAssist do not have a rear
compartment fuse block.