2021 CHEVROLET BLAZER check engine

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14608203) - 2021 - CRC - 10/29/20
262 Vehicle Care
11. Remote Negative (-) Battery Terminal.SeeJump Starting - North America 0318.
Engine Oil
To ensure proper engine performance and
long life, careful attention must be paid to
engine oil. Following these simple, but
important steps will help protect your
investment:
.Use engine oil approved to the proper
specification and of the proper viscosity
grade. See “Selecting the Right Engine
Oil” in this section.
.Check the engine oil level regularly and
maintain the proper oil level. See
“Checking Engine Oil” and“When to Add
Engine Oil” in this section.
.Change the engine oil at the appropriate
time. SeeEngine Oil Life System 0264.
.Always dispose of engine oil properly. See
“What to Do with Used Oil” in this
section.
Checking Engine Oil
Check the engine oil level regularly, every
650 km (400 mi), especially prior to a long
trip. The engine oil dipstick handle is a loop.
See Engine Compartment Overview 0257 for
the location.
{Warning
The engine oil dipstick handle may be
hot; it could burn you. Use a towel or
glove to touch the dipstick handle.
If a low oil Driver Information Center (DIC)
message displays, check the oil level.
Follow these guidelines:
.To get an accurate reading, park the
vehicle on level ground. Check the engine
oil level after the engine has been off for
at least two hours. Checking the engine
oil level on steep grades or too soon after
engine shutoff can result in incorrect
readings. Accuracy improves when
checking a cold engine prior to starting.
Remove the dipstick and check the level.
.If unable to wait two hours, the engine
must be off for at least 15 minutes if the
engine is warm, or at least 30 minutes if
the engine is not warm. Pull out the
dipstick, wipe it with a clean paper towel
or cloth, then push it back in all the way.
Remove it again, keeping the tip down,
and check the level.
When to Add Engine Oil
2.0L L4 Engine
2.5L L4 Engine
3.6L V6 Engine
If the oil is below the cross-hatched area at
the tip of the dipstick and the engine has
been off for at least 15 minutes, add 1 L (1
qt) of the recommended oil and then

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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Vehicle Care 263
recheck the level. See“Selecting the Right
Engine Oil” later in this section for an
explanation of what kind of oil to use. For
engine oil crankcase capacity, see Capacities
and Specifications 0345.
Caution
Do not add too much oil. Oil levels above
or below the acceptable operating range
shown on the dipstick are harmful to the
engine. If the oil level is above the
operating range (i.e., the engine has so
much oil that the oil level gets above the
cross-hatched area that shows the proper
operating range), the engine could be
damaged. Drain the excess oil or limit
driving of the vehicle, and seek a service
professional to remove the excess oil.
See Engine Compartment Overview 0257 for
the location of the engine oil fill cap.
Add enough oil to put the level somewhere
in the proper operating range. Push the
dipstick all the way back in when through.
Selecting the Right Engine Oil
Selecting the right engine oil depends on
both the proper oil specification and
viscosity grade. See Recommended Fluids
and Lubricants 0340.
Specification
Use full synthetic engine oils that meet the
dexos1 specification. Engine oils that have
been approved by GM as meeting the
dexos1 specification are marked with the
dexos1 approved logo. See
www.gmdexos.com.
Caution
Failure to use the recommended engine
oil or equivalent can result in engine
damage not covered by the vehicle
warranty. Viscosity Grade
Use SAE 0W-20 viscosity grade engine oil for
the 2.0L L4 and 2.5L L4 engines.
Use SAE 5W-30 viscosity grade engine oil for
the 3.6L V6 engine. Cold Temperature
Operation: In an area of extreme cold,
where the temperature falls below
−29 °C
(−20 °F), an SAE 0W-30 oil may be used. An
oil of this viscosity grade will provide easier
cold starting for the engine at extremely
low temperatures.
When selecting an oil of the appropriate
viscosity grade, it is recommended to select
an oil of the correct specification. See
“Specification” earlier in this section.
Engine Oil Additives/Engine Oil Flushes
Do not add anything to the oil. The
recommended oils meeting the dexos1
specification are all that is needed for good
performance and engine protection.
Engine oil system flushes are not
recommended and could cause engine
damage not covered by the vehicle
warranty.

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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264 Vehicle Care
What to Do with Used Oil
Used engine oil contains certain elements
that can be unhealthy for your skin and
could even cause cancer. Do not let used oil
stay on your skin for very long. Clean your
skin and nails with soap and water, or a
good hand cleaner. Wash or properly
dispose of clothing or rags containing used
engine oil. See the manufacturer's warnings
about the use and disposal of oil products.
Used oil can be a threat to the environment.
If you change your own oil, be sure to drain
all the oil from the filter before disposal.
Never dispose of oil by putting it in the
trash or pouring it on the ground, into
sewers, or into streams or bodies of water.
Recycle it by taking it to a place that
collects used oil.
Engine Oil Life System
When to Change Engine Oil
This vehicle has a computer system that
indicates when to change the engine oil and
filter. This is based on a combination of
factors which include engine revolutions,
engine temperature, and miles driven. Based
on driving conditions, the mileage at which
an oil change is indicated can varyconsiderably. For the oil life system to work
properly, the system must be reset every
time the oil is changed.
When the system has calculated that oil life
has been diminished, it indicates that an oil
change is necessary. A CHANGE ENGINE OIL
SOON message comes on. Change the oil as
soon as possible within the next 1 000 km
(600 mi). It is possible that, if driving under
the best conditions, the oil life system
might indicate that an oil change is not
necessary for up to a year. The engine oil
and filter must be changed at least once a
year and, at this time, the system must be
reset. Your dealer has trained service people
who will perform this work and reset the
system. It is also important to check the oil
regularly over the course of an oil drain
interval and keep it at the proper level.
If the system is ever reset accidentally, the
oil must be changed at 5 000 km (3,000 mi)
since the last oil change. Remember to reset
the oil life system whenever the oil is
changed.
How to Reset the Engine Oil Life System
Reset the system whenever the engine oil is
changed so that the system can calculate
the next engine oil change. To reset the
system:
1. Display the REMAINING OIL LIFE on the DIC. See Driver Information Center (DIC)
(Base and Midlevel) 0107 or
Driver Information Center (DIC) (Uplevel)
0 110.
2. Press and hold the thumbwheel on the DIC while the Oil Life display is active.
3. Confirm yes, and the oil life will change to 100%.
The oil life system can also be reset as
follows: 1. Place the ignition in Service Mode. See Ignition Positions 0200.
2. Display REMAINING OIL LIFE on the DIC menu. See Driver Information Center
(DIC) (Base and Midlevel) 0107 or
Driver Information Center (DIC) (Uplevel)
0 110.
3. Fully press and release the accelerator pedal three times within five seconds.
4. If the display changes to 100%, the system is reset.

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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Vehicle Care 265
If the CHANGE ENGINE OIL SOON message
comes back on when the vehicle is started,
the engine oil life system has not been
reset. Repeat the procedure.
Automatic Transmission Fluid
It is not necessary to check the transmission
fluid level. A transmission fluid leak is the
only reason for fluid loss. If a leak occurs,
take the vehicle to the dealer and have it
repaired as soon as possible.
Change the fluid at the intervals listed in
Maintenance Schedule0332, and be sure to
use the transmission fluid listed in
Recommended Fluids and Lubricants 0340.
Caution
Use of the incorrect automatic
transmission fluid may damage the
vehicle, and the damage may not be
covered by the vehicle warranty. Always
use the correct automatic transmission
fluid. See Recommended Fluids and
Lubricants 0340.
If you need to check the transmission fluid
level, take the vehicle to your dealer.
Engine Air Filter Life System
If equipped, this feature provides the engine
air filter’s remaining life and best timing for
a change. The timing to change an engine
air filter depends on driving and
environmental conditions.
When to Change the Engine Air Filter
When the Driver Information Center (DIC)
displays a message to replace the engine air
filter at the next oil change, follow this
timing.
When the DIC displays a message to replace
the engine air filter soon, replace the engine
air filter at the earliest convenience.
The system must be reset after the engine
air filter is changed.
If the DIC displays a message to check the
engine air filter system, see your dealer.
How to Reset the Engine Air Filter Life
System
To reset: 1. Place the vehicle in P (Park). 2. Display the Air Filter Life on the DIC. See
Driver Information Center (DIC) (Base and
Midlevel) 0107 or
Driver Information Center (DIC) (Uplevel)
0 110.
3. Press
Tto move to the Reset/Disable
display area. Select Reset then press the
thumbwheel.
4. Press the thumbwheel to confirm the reset.
Engine Air Cleaner/Filter
The engine air cleaner/filter is in the engine
compartment. See Engine Compartment
Overview 0257.
When to Inspect the Engine Air Cleaner/
Filter
If the vehicle is not equipped with the
engine air filter life system, see
Maintenance Schedule 0332 for intervals on
inspecting and replacing the engine air
cleaner/filter.
How to Inspect/Replace the Engine Air
Cleaner/Filter
Do not start the engine or have the engine
running with the engine air cleaner/filter
housing open. Before removing the engine

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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268 Vehicle Care
2.5L L4 Engine
1. Engine Cooling Fan (Out of View)
2. Engine Coolant Surge Tank andPressure Cap
3.6L V6 Engine
1. Engine Cooling Fan (Out of View)
2. Engine Coolant Surge Tank andPressure Cap
{Warning
An underhood electric fan 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
Do not touch heater or radiator hoses,
or other engine parts. They can be very
hot and can burn you. Do not run the
engine if there is a leak; all coolant could
leak out. That could cause an engine fire
and can burn you. Fix any leak before
driving the vehicle.
Engine Coolant
The cooling system in the vehicle is filled
with DEX-COOL engine coolant. This coolant
needs to be checked and replaced at
appropriate intervals. See Maintenance
Schedule 0332.
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 0271.
What to Use
{Warning
Do not touch heater or radiator hoses,
or other engine parts. They can be very
hot and can burn you. Do not run the
(Continued)

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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Vehicle Care 269
Warning (Continued)
engine if there is a leak; all coolant could
leak out. That could cause an engine fire
and can burn you. Fix any leak before
driving the vehicle.
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.
Caution
Do not use anything other than a mix of
DEX-COOL coolant that meets GM
Standard GMW3420 and clean, drinkable
water. Anything else can cause damage
to the engine cooling system and the
vehicle, which would not be covered by
the vehicle warranty. Never dispose of engine coolant by putting
it in the trash, or by 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. See
Engine
Overheating 0271. The coolant surge tank is in the engine
compartment on the driver side of the
vehicle. See
Engine Compartment Overview
0 257.
How to Add Coolant to the Coolant
Surge Tank
{Warning
Spilling coolant on hot engine parts can
burn you. Coolant contains ethylene
glycol and it will burn if the engine parts
are hot enough.
{Warning
Steam and scalding liquids from a hot
cooling system are under pressure.
Turning the pressure cap, even a little,
can cause them to come out at high
speed and you could be burned. Never
turn the cap when the cooling system,
including the pressure cap, is hot. Wait
for the cooling system and pressure cap
to cool.

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14608203) - 2021 - CRC - 10/29/20
270 Vehicle Care
{Warning
Plain water, or other liquids such as
alcohol, can boil before the proper
coolant mixture will. With plain water or
the wrong mixture, the engine could get
too hot but there would not be an
overheat warning. The engine could catch
fire and you or others could be burned.
Caution
Failure to follow the specific coolant fill
procedure could cause the engine to
overheat and could cause system
damage. If coolant is not visible in the
surge tank, contact your dealer.
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 or above the indicated mark, add a
50/50 mixture of clean, drinkable water and
DEX-COOL coolant. Be sure the cooling
system, including the coolant surge tank
pressure cap, is cool before you do it.
2.5L L4 and 3.6L V6 Engines
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 theproper 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
mixture to the coolant surge tank until
the level reaches the indicated
level mark.
5. Replace the pressure cap tightly.

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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Vehicle Care 271
6. Verify coolant level after the engine isshut off and the coolant is cold.
If necessary, repeat coolant fill procedure
Steps 1–6.
If the coolant still is not at the proper
level when the system cools down again,
see your dealer.
Caution
If the pressure cap is not tightly installed,
coolant loss and engine damage may
occur. Be sure the cap is properly and
tightly secured.
2.0L L4 Engine Only - Automatic Coolant
Service Fill Instructions
If equipped, this feature assists in filling and
removing air from the cooling system after
service of components or when coolant is
added after being too low.
To activate the fill and air removal process:
1. With a cold system, add coolant to the indicated mark on the surge tank.
2. Replace the cap on the surge tank.
3. Connect the vehicle to a battery charger.
4. Turn the ignition to Service Mode. See Ignition Positions 0200. 5. Turn off the air conditioning.
6. Set the parking brake.
7. At the same time, press the accelerator
and the brake for two seconds, then
release.
At the end of the cycle, check the coolant
level in the surge tank and add coolant if it
is low. Turn off the vehicle, allow the
Electronic Control Module (ECM) to go to
sleep, about two minutes, and repeat
Steps 4–7.
Listen for pump activation and movement of
the control valves while watching the level
of the coolant in the surge tank. If the tank
empties, turn the ignition off, carefully
remove the surge tank cap, refill to the
indicated mark, and repeat Steps 4–7. The
fill and air removal process will run for
approximately 10 minutes.
Engine Overheating
The vehicle has several indicators to warn of
the engine overheating.
There is an engine coolant temperature
gauge on the instrument cluster. See Engine
Coolant Temperature Gauge 096. The
vehicle may also display a message on the
Driver Information Center (DIC). If the decision is made not to lift the hood
when this warning appears, get service help
right away. See
Roadside Assistance Program
0 352.
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.
Caution
Do not run the engine if there is a leak
in the engine cooling system. This can
cause a loss of all coolant and can
damage the system and vehicle. Have
any leaks fixed right away.
If Steam Is Coming from the Engine
Compartment
{Warning
Steam and scalding liquids from a hot
cooling system are under pressure.
Turning the pressure cap, even a little,
can cause them to come out at high (Continued)