
Black plate (15,1)Chevrolet Sonic Owner Manual - 2012
Vehicle Care 10-15
1.8L L4 Engine
1. Remove the two screws, tilt the cover, and slide it out of the
assembly.
2. Inspect or replace the engine air cleaner/filter.
3. Lower the cover, slide it into the assembly, then secure with the
two screws.
See Maintenance Schedule on
page 11‑3 for replacement intervals.
{WARNING
Operating the engine with the air
cleaner/filter off can cause you or
others to be burned. The air
cleaner not only cleans the air; it
helps to stop flames if the engine
backfires. Use caution when
working on the engine and do not
drive with the air cleaner/filter off.
Notice: If the air cleaner/filter is
off, dirt can easily get into the
engine, which could damage it.
Always have the air cleaner/filter
in place when you are driving.
Cooling System
The cooling system allows the
engine to maintain the correct
working temperature.
1.4L L4 Engine
A. Engine Electric Cooling Fan (Out of View)
B. Engine Coolant Surge Tank and Pressure Cap

Black plate (16,1)Chevrolet Sonic Owner Manual - 2012
10-16 Vehicle Care
1.8L L4 Engine
A. Engine Electric Cooling Fan (Out of View)
B. Engine 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 may require changing
sooner, at the first maintenance
service after each 30,000 miles
(50 000 km) or 24 months,
whichever occurs first. Any
repairs would not be covered by
the vehicle warranty. Always use
DEX‐COOL
®(silicate‐free) coolant
in the vehicle.
Engine Coolant
The cooling system in the vehicle is
filled with DEX-COOL engine
coolant. This coolant is designed to
remain in the vehicle for 5 years or
240 000 km (150,000 mi), whichever
occurs first.
The following explains the cooling
system and how to check and add
coolant when it is low. If there is a
problem with engine overheating,
see Engine Overheating on
page 10‑20.
What to Use
{WARNING
Adding only plain water or some
other liquid to the cooling system
can be dangerous. Plain water
and other liquids, can boil before
the proper coolant mixture will.
The coolant warning system is set
for the proper coolant mixture.
(Continued)

Black plate (17,1)Chevrolet Sonic Owner Manual - 2012
Vehicle Care 10-17
WARNING (Continued)
With plain water or the wrong
mixture, the engine could get too
hot but you would not get the
overheat warning. The engine
could catch fire and you or
others could be burned. Use a
50/50 mixture of clean, drinkable
water and DEX-COOL coolant.
Use a 50/50 mixture of clean
drinkable water and DEX-COOL
coolant. This mixture:
.Gives freezing protection down
to −37°C (−34°F), outside
temperature.
.Gives boiling protection up to
129°C (265°F), engine
temperature.
.Protects against rust and
corrosion.
.Will not damage aluminum parts.
.Helps keep the proper engine
temperature.
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 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.
It is normal to see coolant moving in
the upper coolant hose return line
when the engine is running.
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
clean drinkable water and
DEX-COOL coolant.
Be sure the cooling system is cool
before this is done.

Black plate (18,1)Chevrolet Sonic Owner Manual - 2012
10-18 Vehicle Care
If no coolant is visible in the coolant
surge tank, add coolant as follows:
How to Add Coolant to the
Coolant Surge Tank
Notice:This vehicle has a
specific coolant fill procedure.
Failure to follow this procedure
could cause the engine to
overheat and be severely
damaged.
If no problem is found, check to see
if coolant is visible in the coolant
surge tank. If coolant is visible
but the coolant level is not at
the indicated level mark, add a
50/50 mixture of clean, drinkable
water and DEX-COOL coolant at
the coolant surge tank, but be sure
the cooling system, including the
coolant surge tank pressure cap,
is cool before you do it.
{WARNING
Steam and scalding liquids from a
hot cooling system can blow out
and burn you badly. They are
under pressure, and if you turn
the coolant surge tank pressure
cap —even a little —they can
come out at high speed. Never
turn the cap when the cooling
system, including the coolant
surge tank pressure cap, is hot.
Wait for the cooling system and
coolant surge tank pressure cap
to cool if you ever have to turn
the pressure cap.
{WARNING
Adding only plain water or some
other liquid to the cooling system
can be dangerous. Plain water
and other liquids, can boil before
the proper coolant mixture will.
The coolant warning system is set
for the proper coolant mixture.
With plain water or the wrong
mixture, the engine could get too
hot but you would not get the
overheat warning. The engine
could catch fire and you or
others could be burned. Use a
50/50 mixture of clean, drinkable
water and DEX-COOL coolant.
Notice: In cold weather, water
can freeze and crack the engine,
radiator, heater core and other
parts. Use the recommended
coolant and the proper coolant
mixture.

Black plate (19,1)Chevrolet Sonic Owner Manual - 2012
Vehicle Care 10-19
{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.
1.4L Engine Shown, 1.8L EngineSimilar
1. Remove the coolant surge tank pressure cap when the cooling
system, including the coolant
surge tank pressure cap and
upper radiator hose, is no
longer hot. Turn the pressure cap slowly
counterclockwise about
one-quarter of a turn. If you
hear a hiss, wait for that to
stop. This will allow any
pressure still left to be vented
out the discharge hose.
2. Keep turning the pressure cap slowly and remove it.
3. Fill the coolant surge tank with
the proper DEX-COOL coolant
mixture to the indicated
level mark. 4. With the coolant surge tank
pressure cap off, start the
engine and let it run until you
can feel the upper radiator hose
getting hot. Watch out for the
engine cooling fan.
By this time, the coolant level
inside the coolant surge tank
may be lower. If the level is
lower, add more of the proper
DEX-COOL coolant mixture to
the coolant surge tank until the
level reaches the indicated
level mark.
5. Replace the pressure cap. Be sure the pressure cap is
hand-tight.
Check the level in the coolant surge
tank when the cooling system has
cooled down. If the coolant is not at
the proper level, repeat Steps 1
through 3 and reinstall the pressure
cap. If the coolant still is not at the
proper level when the system cools
down again, see your dealer.

Black plate (20,1)Chevrolet Sonic Owner Manual - 2012
10-20 Vehicle Care
Engine Overheating
The vehicle has an indicator to warn
of the engine overheating.
If the decision is made not to lift the
hood when this warning appears,
get service help right away. See
Roadside Assistance Program on
page 13‑5.
If the decision is made to lift the
hood, make sure the vehicle is
parked on a level surface.
Then check to see if the engine
cooling fan is running. If the engine
is overheating, the fan should be
running. If it is not, do not continue
to run the engine. Have the vehicle
serviced.
Notice:Engine damage from
running the engine without
coolant is not covered by the
warranty. Notice:
If the engine catches fire
because of being driven with no
coolant, the vehicle can be badly
damaged. The costly repairs
would not be covered by the
vehicle warranty.
If Steam Is Coming from the
Engine Compartment
{WARNING
Steam from an overheated engine
can burn you badly, even if you
just open the hood. Stay away
from the engine if you see or hear
steam coming from it. Just turn it
off and get everyone away from
the vehicle until it cools down.
Wait until there is no sign of
steam or coolant before you open
the hood.
If you keep driving when the
engine is overheated, the liquids
in it can catch fire. You or others
could be badly burned. Stop the
(Continued)
WARNING (Continued)
engine if it overheats, and get out
of the vehicle until the engine
is cool.
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 may 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.
If the overheat warning is displayed
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.

Black plate (36,1)Chevrolet Sonic Owner Manual - 2012
10-36 Vehicle Care
Number Usage28 Heated Outside
Rearview Mirror
29 Not Used
30 Heated Front Seat
31 Fuel System
Control Module 1
(1.4L), Not
Used (1.8L)
32 Flex Fuel
33 Washer
34 Fuel Pump
Relay (1.8L)
35 Fuel Pump (1.8L)
36 Engine Control
Module/
Transmission
Control Module
37 Fuel System
Control Module 2
(1.4L), Not
Used (1.8L)
38 Not Used Number Usage
39 Cooling Fan K5
40 Cooling Fan K4
41 EVP
42 Engine Control
Module
43 Air Conditioning
Compressor Clutch
44 Transmission
Control Module
45 Engine Control
Module 1
46 Coil
47 Engine Control
Module 4
48 Engine Control
Module 3
49 Engine Control
Module 2
50 Injector
51 Powertrain Relay Number Usage
52 Horn
53 Cooling Fan K3
Relay (1.8L),
Cooling Fan K3
High Current
Relay (1.4L)
54 Start
55 Start Relay
56 Air Conditioning
Compressor Clutch
Relay
57 High‐Beam Relay
58 Front Fog Lamps
59 Left High Beam
60 Right High Beam
61 Cooling Fan K1
Relay
62 Cooling Fan K2
Relay (1.4L)

Black plate (57,1)Chevrolet Sonic Owner Manual - 2012
Vehicle Care 10-57
Replace wheels, wheel bolts, wheel
nuts, or Tire Pressure Monitor
System (TPMS) sensors with new
GM original equipment parts.
{WARNING
Using the wrong replacement
wheels, wheel bolts, or wheel
nuts can be dangerous. It could
affect the braking and handling of
the vehicle. Tires can lose air,
and cause loss of control, causing
a crash. Always use the correct
wheel, wheel bolts, and wheel
nuts for replacement.
Notice: The wrong wheel can
also cause problems with bearing
life, brake cooling, speedometer
or odometer calibration,
headlamp aim, bumper height,
vehicle ground clearance, and tire
or tire chain clearance to the
body and chassis.
See If a Tire Goes Flat on
page 10‑58 for more information.
Used Replacement Wheels
{WARNING
Replacing a wheel with a used
one is dangerous. How it has
been used or how far it has been
driven may be unknown. It could
fail suddenly and cause a crash.
When replacing wheels, use a
new GM original equipment
wheel.
Tire Chains
{WARNING
Do not use tire chains. There is
not enough clearance. Tire chains
used on a vehicle without the
proper amount of clearance can
cause damage to the brakes,
suspension, or other vehicle
(Continued)
WARNING (Continued)
parts. The area damaged by the
tire chains could cause loss of
control and a crash.
Use another type of traction
device only if its manufacturer
recommends it for the vehicle's
tire size combination and road
conditions. Follow that
manufacturer's instructions. To
avoid vehicle damage, drive slow
and readjust or remove the
traction device if it contacts the
vehicle. Do not spin the wheels.
If traction devices are used, install
them on the front tires.