2021 CHEVROLET TRAILBLAZER service manual

Chevrolet Trailblazer Owner Manual (GMNA-Localizing-U.S./Canada-
14400528) - 2021 - CRC - 11/7/19
Vehicle Care 245
Accessories and Modifications
Adding non-dealer accessories or making
modifications to the vehicle can affect
vehicle performance and safety, including
such things as airbags, braking, stability,
ride and handling, emissions systems,
aerodynamics, durability, and electronic
systems like antilock brakes, traction control,
and stability control. These accessories or
modifications could even cause malfunction
or damage not covered by the vehicle
warranty.
Damage to suspension components caused
by modifying vehicle height outside of
factory settings will not be covered by the
vehicle warranty.
Damage to vehicle components resulting
from modifications or the installation or use
of non-GM certified parts, including control
module or software modifications, is not
covered under the terms of the vehicle
warranty and may affect remaining
warranty coverage for affected parts.
GM Accessories are designed to complement
and function with other systems on the
vehicle. See your dealer to accessorize the
vehicle using genuine GM Accessories
installed by a dealer technician.Also, see
Adding Equipment to the
Airbag-Equipped Vehicle 060.
Vehicle Checks
Doing Your Own Service Work
{Warning
It can be dangerous to work on your
vehicle if you do not have the proper
knowledge, service manual, tools,
or parts. Always follow owner’s manual
procedures and consult the service
manual for your vehicle before doing any
service work.
If doing some of your own service work, use
the proper service manual. It tells you much
more about how to service the vehicle than
this manual can. To order the proper service
manual, see Publication Ordering
Information 0339.
This vehicle has an airbag system. Before
attempting to do your own service work,
see Servicing the Airbag-Equipped Vehicle
0 59. If equipped with remote vehicle start, open
the hood before performing any service
work to prevent remote starting the vehicle
accidentally. See
Remote Vehicle Start 017.
Keep a record with all parts receipts and list
the mileage and the date of any service
work performed. See Maintenance Records
0 327.Caution
Even small amounts of contamination can
cause damage to vehicle systems. Do not
allow contaminants to contact the fluids,
reservoir caps, or dipsticks.
Hood
{Warning
For vehicles with auto engine stop/start,
turn the vehicle off before opening the
hood. If the vehicle is on, the engine will
start when the hood is opened. You or
others could be injured.

Chevrolet Trailblazer Owner Manual (GMNA-Localizing-U.S./Canada-
14400528) - 2021 - CRC - 11/7/19
Vehicle Care 251
Caution (Continued)
engine has so much oil that the oil level
gets above the MAX mark, the engine
could be damaged. You should drain out
the excess oil or limit driving of the
vehicle and seek a service professional to
remove the excess amount of oil.
See Engine Compartment Overview 0247 for
the location of the engine oil fill cap.
Add enough oil to put the level somewhere
in the proper operating range between the
MIN and MAX marks. 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 0325.
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
For the 1.3L L3 engine, use SAE 0W-20
viscosity grade engine oil.
For the 1.2L L3 engine, use SAE 5W-30
viscosity grade engine oil. 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.
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.

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-
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
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-
14400528) - 2021 - CRC - 11/7/19
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.

Chevrolet Trailblazer Owner Manual (GMNA-Localizing-U.S./Canada-
14400528) - 2021 - CRC - 11/7/19
Vehicle Care 263
Caution (Continued)
.Tighten the nut with a hand tool. Do
not use an impact wrench or power
tools to tighten the nut.
The vehicle could be damaged if these
guidelines are not followed.
Caution
Do not use paints, lubricants, or corrosion
inhibitors on the nut that secures the
negative battery cable to the vehicle. This
could damage the vehicle.
1. Install the negative battery cable (2) to the battery.
2. Install the negative battery cable nut (1) and tighten.
3. Turn the ignition on.
All-Wheel Drive
Transfer Case
Under normal driving conditions, transfer
case fluid does not require maintenance
unless there is a fluid leak or unusual noise.
If required, have the transfer case serviced
by your dealer.
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). If the vehicle starts in any
other position, contact your dealer for
service.
Automatic Transmission Shift Lock
Control Function 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.
It should be parked on a level surface.
2. Apply the parking brake. Be ready to apply the regular brake immediately if
the vehicle begins to move.
3. With the engine off, turn the ignition on, but do not start the engine. Without
applying the regular brake, try to move
the shift lever out of P (Park) with
normal effort. If the shift lever moves
out of P (Park), contact your dealer for
service.

Chevrolet Trailblazer Owner Manual (GMNA-Localizing-U.S./Canada-
14400528) - 2021 - CRC - 11/7/19
264 Vehicle Care
Park Brake and P (Park)
Mechanism Check
{Warning
When you are doing this check, the
vehicle could begin to move. You or
others could be injured and property
could be damaged. Make sure there is
room in front of the vehicle in case it
begins to roll. Be ready to apply the
regular brake at once should the vehicle
begin to move.
Park on a fairly steep hill, with the vehicle
facing downhill. Keeping your foot on the
regular brake, set the parking brake.
.To check the parking brake's holding
ability: With the engine running and the
transmission in N (Neutral), slowly remove
foot pressure from the regular brake
pedal. Do this until the vehicle is held by
the parking brake only.
.To check the P (Park) mechanism's holding
ability: With the engine running, shift to
P (Park). Then release the parking brake
followed by the regular brake.
Contact your dealer if service is required.
Wiper Blade Replacement
Windshield wiper blades should be replaced
periodically. See Maintenance Schedule
0 316.
Replacement blades come in different types
and are removed in different ways. For
proper type and length, see Maintenance
Replacement Parts 0326.
Caution
Allowing the wiper arm to touch the
windshield when no wiper blade is
installed could damage the windshield.
Any damage that occurs would not be
covered by the vehicle warranty. Do not
allow the wiper arm to touch the
windshield.
Front Wiper Blade Replacement
To replace the front wiper blades:
1. Lift the wiper arm from the windshield until no further movement is possible.
2. Press the release button on the top side
of the wiper and pull the wiper blade
out of the end of the wiper arm.
3. Install the wiper blade connector by sliding into the end of the wiper arm
until the button on the wiper blade clicks
into place with the wiper arm.
4. Place the wiper arm with the wiper blade in place back on the windshield.
Caution
Damage may occur if the wiper blades
are not in contact with the windshield
before turning on the wiper system.