2012 CHEVROLET EXPRESS check engine

Black plate (14,1)Chevrolet Express Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707481) - 2015 - CRC - 4/30/14
10-14 Vehicle Care
Cooling System
The cooling system allows the
engine to maintain the correct
working temperature.
1. Radiator Pressure Cap
2. Coolant Recovery Tank
3. Engine Cooling Fan (Outof View)
{Warning
An electric engine cooling fan can
start even when the engine is not
running. To avoid injury, always
keep hands, clothing, and tools
away from any engine
cooling 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.
{Caution
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.
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 10-18.

Black plate (16,1)Chevrolet Express Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707481) - 2015 - CRC - 4/30/14
10-16 Vehicle Care
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 recovery tank. If the
coolant inside the coolant recovery
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 COLD FILL mark, add
a 50/50 mixture of clean, drinkable
water and DEX-COOL coolant at the
coolant recovery tank, but be sure
the cooling system is cool before
this is done.
The coolant recovery tank cap has
this symbol on it.When the engine is cold, the coolant
level should be at or above the
COLD FILL mark. If it is not, there
could be a leak in the cooling
system.
If the coolant is low, add the coolant
or take the vehicle to a dealer for
service.
How to Add Coolant to the
Recovery Tank for Gasoline
Engines
{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.
{Caution
This vehicle has a specific
coolant fill procedure. Failure to
follow this procedure could cause
the engine to overheat and be
severely damaged.
If coolant is needed, add the proper
DEX-COOL coolant mixture at the
coolant recovery tank.
How to Add Coolant to the
Radiator
{Warning
Steam and scalding liquids from a
hot cooling system can blow out
and burn you badly. Never turn
the cap when the cooling system,
including the surge tank pressure
cap, is hot. Wait for the cooling
system and surge tank pressure
cap to cool.

Black plate (18,1)Chevrolet Express Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707481) - 2015 - CRC - 4/30/14
10-18 Vehicle Care
6. Start the engine and let it rununtil the upper radiator hose can
be felt getting hot. Watch out for
the engine cooling fan.
7. By this time, the coolant level inside the radiator filler neck
may be lower. If the level is
lower, add more of the proper
DEX-COOL coolant mixture
through the filler neck until the
level reaches the base of the
filler neck. 8. Replace the pressure cap. At
any time during this procedure if
coolant begins to flow out of the
filler neck, reinstall the
pressure cap.
{Caution
If the pressure cap is not tightly
installed, coolant loss and
possible engine damage may
occur. Be sure the cap is properly
and tightly secured.
Engine Overheating
If the vehicle has a diesel engine,
see the Duramax diesel
supplement.
The vehicle has an indicator to warn
of engine overheating.
There is an engine coolant
temperature gauge on the vehicle's
instrument cluster. See Engine
Coolant Temperature Gauge on
page 5-13. If the decision is made not to lift the
hood when this warning appears,
but instead 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 fans are running. If the
engine is overheating, the fan
should be running. If it is not, do not
continue to run the engine and have
the vehicle serviced.
See if the engine cooling fan speed
increases when idle speed is
doubled by pushing the accelerator
pedal down. If it does not, the
vehicle needs service. Turn off the
engine.

Black plate (19,1)Chevrolet Express Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707481) - 2015 - CRC - 4/30/14
Vehicle Care 10-19
{Caution
Running the engine without
coolant may cause damage or a
fire. Vehicle damage 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.(Continued)
Warning (Continued)
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
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.
.Tows a trailer. See“Driving on
Grades” underTrailer Towing on
page 9-47. If the overheat warning is displayed
with no sign of steam:
1. Turn the air off.
2. Turn the heater on to the highest
temperature and to the highest
fan speed. Open the windows as
necessary.
3. When it is safe to do so, pull off the road, shift to P (Park) or
N (Neutral) and let the
engine idle.
If the engine coolant temperature
gauge is no longer in the overheat
zone or an overheat warning 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 and have the cooling
system checked for proper fit and
function.
If the warning continues, pull over,
stop, and park the vehicle
right away.

Black plate (20,1)Chevrolet Express Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707481) - 2015 - CRC - 4/30/14
10-20 Vehicle Care
If there is still no sign of steam,
push down the accelerator until the
engine speed is about twice as fast
as normal idle speed for at least
three minutes while parked. If the
warning is still on, turn off the
engine until it cools down.
If the decision is made not to lift the
hood, get service help right away.
Engine Fan
The vehicle has a clutched engine
cooling fan. When the clutch is
engaged, the fan spins faster to
provide more air to cool the engine.
In most everyday driving conditions,
the fan is spinning slower and the
clutch is not fully engaged. This
improves fuel economy and reduces
fan noise. Under heavy vehicle
loading, trailer towing, and/or high
outside temperatures, the fan speed
increases as the clutch more fully
engages, so an increase in fan
noise may be heard. This is normal
and should not be mistaken as the
transmission slipping or makingextra shifts. It is merely the cooling
system functioning properly. The fan
will slow down when additional
cooling is not required and the
clutch partially disengages.
This fan noise may be heard when
starting the engine. It will go away
as the fan clutch partially
disengages.
Power Steering Fluid
The power steering fluid reservoir is
in the engine compartment on the
driver side of the vehicle. See
Engine Compartment Overview on
page 10-5
for reservoir location.
When to Check Power Steering
Fluid
It is not necessary to regularly
check power steering fluid unless
there is a leak suspected in the
system or an unusual noise is
heard. A fluid loss in this system
could indicate a problem. Have the
system inspected and repaired.
How to Check Power Steering
Fluid
To check the power steering fluid:
1. Turn the key off and let the
engine compartment cool down.
2. Wipe the cap and the top of the reservoir clean.
3. Unscrew the cap and wipe the dipstick with a clean rag.
4. Replace the cap and completely tighten it.
5. Remove the cap again and look at the fluid level on the dipstick.

Black plate (21,1)Chevrolet Express Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707481) - 2015 - CRC - 4/30/14
Vehicle Care 10-21
The level should be at the COLD
FILL mark. If necessary, add only
enough fluid to bring the level up to
the mark.
To prevent contamination of brake
fluid, never check or fill the power
steering reservoir with the brake
master cylinder cover off.
What to Use
{Caution
Use of the incorrect fluid may
damage the vehicle and the
damages may not be covered by
the vehicle warranty. Always use
the correct fluid listed in
Recommended Fluids and
Lubricants on page 11-11.
To determine what kind of fluid to
use, see Recommended Fluids and
Lubricants on page 11-11. Always
use the proper fluid. Failure to use
the proper fluid can cause leaks and
damage hoses and seals.
Washer Fluid
What to Use
When the vehicle needs windshield
washer fluid, be sure to read the
manufacturer's instructions before
use. If operating the vehicle in an
area where the temperature may fall
below freezing, use a fluid that has
sufficient protection against
freezing.
Adding Washer Fluid
Open the cap with the washer
symbol on it. Add washer fluid until
the tank is full. See Engine
Compartment Overview on
page 10-5 for reservoir location.
{Caution
.Do not use engine coolant
(antifreeze) in the windshield
washer. It can damage the
windshield washer system
and paint.
.Do not mix water with
ready-to-use washer fluid.
Water can cause the solution
to freeze and damage the
washer fluid tank and other
parts of the washer system.
.When using concentrated
washer fluid, follow the
manufacturer instructions for
adding water.
.Fill the washer fluid tank only
three-quarters full when it is
very cold. This allows for fluid
expansion if freezing occurs,
which could damage the tank
if it is completely full.

Black plate (23,1)Chevrolet Express Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707481) - 2015 - CRC - 4/30/14
Vehicle Care 10-23
Brake Fluid
The brake master cylinder reservoir
is filled with DOT 3 brake fluid. See
Engine Compartment Overview on
page 10-5for the location of the
reservoir.
There are only two reasons why the
brake fluid level in the reservoir
might go down:
.The brake fluid level goes down
because of normal brake lining
wear. When new linings are
installed, the fluid level goes
back up.
.A fluid leak in the brake
hydraulic system can also cause
a low fluid level. Have the brake
hydraulic system fixed, since a
leak means that sooner or later
the brakes will not work well. Do not top off the brake fluid.
Adding fluid does not correct a leak.
If fluid is added when the linings are
worn, there will be too much fluid
when new brake linings are
installed. Add or remove brake fluid,
as necessary, only when work is
done on the brake hydraulic system.
{Warning
If too much brake fluid is added, it
can spill on the engine and/or fuel
operated heater parts,
if equipped. If the vehicle has a
diesel engine and a fuel operated
heater, see
“Fuel Operated
Heater (FOH)” in the diesel
engine supplement. The fluid will
burn if the engine is hot enough.
You or others could be burned,
and the vehicle could be
damaged. Add brake fluid only
when work is done on the brake
hydraulic system. See “Checking
Brake Fluid” in this section. Refer to the Maintenance Schedule
to determine when to check the
brake fluid. See
Maintenance
Schedule on page 11-3.
Checking Brake Fluid
Check brake fluid by looking at the
brake fluid reservoir. See Engine
Compartment Overview on
page 10-5.
The fluid level should be above
MIN. If it is not, have the brake
hydraulic system checked to see if
there is a leak.

Black plate (26,1)Chevrolet Express Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707481) - 2015 - CRC - 4/30/14
10-26 Vehicle Care
Federal law prohibits the following
acts or the causing thereof:
1. The removal or renderinginoperative by any person, other
than for purposes of
maintenance, repair or
replacement, of any device or
element of design incorporated
into any new vehicle for the
purpose of noise control, prior to
its sale or delivery to the ultimate
purchaser or while it is in use; or
2. The use of the vehicle after such device or element of design has
been removed or rendered
inoperative by any person.
Among those acts presumed to
constitute tampering are the acts
listed below.
Insulation:
.Removal of the noise shields or
any underhood insulation. Engine:
.Removal or rendering engine
speed governor, if the vehicle
has one, inoperative so as to
allow engine speed to exceed
manufacturer specifications.
Fan and Drive:
.Removal of fan clutch, if the
vehicle has one, or rendering
clutch inoperative.
.Removal of the fan shroud, if the
vehicle has one.
Air Intake:
.Removal of the air cleaner
silencer.
.Modification of the air cleaner.
Exhaust:
.Removal of the muffler and/or
resonator.
.Removal of the exhaust pipes
and exhaust pipe clamps. Fuel Operated Heater (FOH)
—
Diesel Engine:
.Removal of the muffler.
Starter Switch 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.
2. Apply both the parking brake and the regular brake.
Do not use the accelerator
pedal, and be ready to turn off
the engine immediately if it
starts.
3. Try to start the engine in each gear. The vehicle should start
only in P (Park) or N (Neutral).