check engine CHEVROLET TRAILBLAZER 2021 Owner's Guide

Chevrolet Trailblazer Owner Manual (GMNA-Localizing-U.S./Canada-
14400528) - 2021 - CRC - 11/7/19
246 Vehicle Care
{Warning
Components under the hood can get hot
from running the engine. To help avoid
the risk of burning unprotected skin,
never touch these components until they
have cooled, and always use a glove or
towel to avoid direct skin contact.
To open the hood:
1. Pull the hood release handle inside the vehicle. It is located on the lower left
side of the instrument panel.
2. Go to the front of the vehicle and movethe secondary hood release lever toward
the right side of the vehicle.
3. Lift the hood and release the hood propfrom its retainer, above the radiator.
Securely place the hood prop into the
slot on the underside of the hood.
To close the hood: 1. Before closing the hood, be sure all filler caps are on properly. Then, lift the hood
to relieve pressure on the hood prop.
Remove the hood prop from the slot in
the underside of the hood and return the
prop to its retainer. The prop rod must
click into place when returning it to the
retainer to prevent hood damage.
2. Lower the hood 30 cm (12 in) above the vehicle and release it so it fully latches.
Check to make sure the hood is closed
and repeat the process if necessary.
{Warning
Do not drive the vehicle if the hood is
not latched completely. The hood could
open fully, block your vision, and cause a
crash. You or others could be injured.
Always close the hood completely before
driving.

Chevrolet Trailblazer Owner Manual (GMNA-Localizing-U.S./Canada-
14400528) - 2021 - CRC - 11/7/19
250 Vehicle Care
9.Battery - North America 0261.
10. Engine Compartment Fuse Block 0274.
11. Remote Negative (-) Battery Terminal. SeeJump Starting - North America 0302
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 0252.
.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 0247 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
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
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 0329.
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 you find that you have an oil
level above the operating range, i.e., the
(Continued)

Chevrolet Trailblazer Owner Manual (GMNA-Localizing-U.S./Canada-
14400528) - 2021 - CRC - 11/7/19
252 Vehicle Care
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 vary
considerably. 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 REMAINING OIL LIFE on the DIC. See Driver Information Center (DIC) (Base
Level) 0104 or
Driver Information Center (DIC) (Uplevel)
0 107. This display shows an estimate of
the oil’s remaining useful life. If 99% is
displayed, that means that 99% of the
current oil life remains.
2. Press and hold
lor the thumbwheel
while the Oil Life display is active.
Confirm reset and the oil life will change
to 100%. The oil life system can also be reset as
follows:
1. Display REMAINING OIL LIFE on the DIC. See Driver Information Center (DIC) (Base
Level) 0104 or
Driver Information Center (DIC) (Uplevel)
0 107.
2. Fully press and release the accelerator pedal three times within five seconds..
3. If the display changes to 100%, the system is reset
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
How to Check 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 your dealer and have it
repaired as soon as possible.

Chevrolet Trailblazer Owner Manual (GMNA-Localizing-U.S./Canada-
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Vehicle Care 253
There is a special procedure for checking and
changing the transmission fluid. Because this
procedure is difficult, you should have this
done at your dealer.
Change the fluid at the intervals listed in
Maintenance Schedule0316, and be sure to
use the fluid listed in Recommended Fluids
and Lubricants 0325.
Engine Air Filter Life System
It 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. Select Air Filter Life on the DIC menu. See Driver Information Center (DIC) (Base
Level) 0104 or
Driver Information Center (DIC) (Uplevel)
0 107.
3. Press
lor the thumbwheel to move to
the Reset/Disable display area. Select
Reset then press
lor press the
thumbwheel for several seconds.
4. Press
lor the thumbwheel to confirm
the reset.
Engine Air Cleaner/Filter
The engine air cleaner/filter is in the engine
compartment on the passenger side of the
vehicle. See Engine Compartment Overview
0 247.
When to Inspect the Engine Air Cleaner/
Filter
If the vehicle is not equipped with the
engine air filter life system, see
Maintenance Schedule 0316 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
air cleaner/filter, make sure that the engine
air cleaner/filter housing and nearby
components are free of dirt and debris. Do
not clean the engine air cleaner/filter with
water or compressed air.

Chevrolet Trailblazer Owner Manual (GMNA-Localizing-U.S./Canada-
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Vehicle Care 255
Cooling System
The cooling system allows the engine to
maintain the correct working temperature.
1.2L L3 Engine (LIH)
1.3L L3 Engine (L3T)
1. Engine Coolant Surge Tank andPressure Cap
2. Engine Cooling Fan (Out of View)
{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
is designed to remain in the vehicle for five
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 0258.
What to Use
{Warning
Plain water, or other liquids such as
alcohol, can boil before the proper
coolant mixture will. With plain water or
(Continued)

Chevrolet Trailblazer Owner Manual (GMNA-Localizing-U.S./Canada-
14400528) - 2021 - CRC - 11/7/19
256 Vehicle Care
Warning (Continued)
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.
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, 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.
If no coolant is visible in the coolant surge
tank, add coolant as follows:
How to Add Coolant to the Coolant
Surge Tank
{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 Trailblazer Owner Manual (GMNA-Localizing-U.S./Canada-
14400528) - 2021 - CRC - 11/7/19
Vehicle Care 257
{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.
{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.
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 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.
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 Trailblazer Owner Manual (GMNA-Localizing-U.S./Canada-
14400528) - 2021 - CRC - 11/7/19
258 Vehicle Care
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.
Automatic Coolant Service Fill Instruction
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, open the surge tank cap and add coolant to the indicated
mark on the surge tank.
2. Connect the vehicle to a battery charger.
3. Turn the ignition to Service Mode. See Ignition Positions (Key Access) 0191 or
Ignition Positions (Keyless Access) 0192.
4. Turn off the air conditioning. 5. Set the parking brake.
6. 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 Engine
Control Module (ECM) to go to sleep, about
two minutes, and repeat Steps 3-7.
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 an engine coolant
temperature gauge to warn of the engine
overheating. See Engine Coolant
Temperature Gauge 094.
If the decision is made not to lift the hood
when this warning appears, get service help
right away. See Roadside Assistance Program
0 335. 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
speed and you could be burned. Never
turn the cap when the cooling system,
(Continued)

Chevrolet Trailblazer Owner Manual (GMNA-Localizing-U.S./Canada-
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Vehicle Care 259
Warning (Continued)
including the pressure cap, is hot. Wait
for the cooling system and pressure cap
to 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
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.
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, 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 fill and
function.
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.
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
0247 for
reservoir location.
Caution
.Do not use washer fluid that contains
any type of water repellent coating.
This can cause the wiper blades to
chatter or skip, and may also clog the
washer nozzle.
.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.
(Continued)

Chevrolet Trailblazer Owner Manual (GMNA-Localizing-U.S./Canada-
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260 Vehicle Care
Caution (Continued)
.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.
Brakes
Disc brake pads have built-in wear indicators
that make a high-pitched warning sound
when the brake pads are worn and new
pads are needed. The sound can come and
go or can be heard all the time when the
vehicle is moving, except when applying the
brake pedal firmly.
{Warning
The brake wear warning sound means
that soon the brakes will not work well.
That could lead to a crash. When the
brake wear warning sound is heard, have
the vehicle serviced.
Caution
Continuing to drive with worn-out brake
pads could result in costly brake repair.
Some driving conditions or climates can
cause a brake squeal when the brakes are
first applied or lightly applied. This does not
mean something is wrong with the brakes.
Properly torqued wheel nuts are necessary
to help prevent brake pulsation. When tires
are rotated, inspect brake pads for wear and
evenly tighten wheel nuts in the proper
sequence to torque specifications. See
Capacities and Specifications 0329.
Brake pads should be replaced as
complete sets.
Brake Pedal Travel
See your dealer if the brake pedal does not
return to normal height, or if there is a
rapid increase in pedal travel. This could be
a sign that brake service may be required.
Replacing Brake System Parts
Always replace brake system parts with
new, approved replacement parts. If this is
not done, the brakes may not work
properly. The braking performance expected can change in many other ways if the
wrong replacement brake parts are installed
or if parts are improperly installed.
Brake Fluid
The brake master cylinder reservoir is filled
with GM approved DOT 4 brake fluid as
indicated on the reservoir cap. See
Engine
Compartment Overview 0247 for the
location of the reservoir.
Checking Brake Fluid
With the vehicle in P (Park) on a level
surface, the brake fluid level should be
between the minimum and maximum marks
on the brake fluid reservoir.
There are only two reasons why the brake
fluid level in the reservoir may go down:
.Normal brake lining wear. When new
linings are installed, the fluid level goes
back up.