check engine CHEVROLET TRAILBLAZER 2021 Owner's Guide

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.

Chevrolet Trailblazer Owner Manual (GMNA-Localizing-U.S./Canada-
14400528) - 2021 - CRC - 11/7/19
274 Vehicle Care
Headlamp Wiring
An electrical overload may cause the lamps
to go on and off, or in some cases to
remain off. Have the headlamp wiring
checked right away if the lamps go on and
off or remain off.
Windshield Wipers
If the wiper motor overheats due to heavy
snow or ice, the windshield wipers will stop
until the motor cools and will then restart.
Although the circuit is protected from
electrical overload, overload due to heavy
snow or ice may cause wiper linkage
damage. Always clear ice and heavy snow
from the windshield before using the
windshield wipers.
If the overload is caused by an electrical
problem and not snow or ice, be sure to get
it fixed.
Fuses and Circuit Breakers
The wiring circuits in the vehicle are
protected from short circuits by a
combination of fuses and circuit breakers.
This greatly reduces the chance of damage
caused by electrical problems.
{Danger
Fuses and circuit breakers are marked
with their ampere rating. Do not exceed
the specified amperage rating when
replacing fuses and circuit breakers. Use
of an oversized fuse or circuit breaker can
result in a vehicle fire. You and others
could be seriously injured or killed.
To check a fuse, look at the silver-colored
band inside the fuse. If the band is broken
or melted, replace the fuse. Be sure to
replace a bad fuse with a new one of the
identical size and rating.
Fuses of the same amperage can be
temporarily borrowed from another fuse
location, if a fuse goes out. Replace the fuse
as soon as possible.
Engine Compartment Fuse Block
To remove the fuse block cover, squeeze the
clip and lift it up.
Caution
Spilling liquid on any electrical
component on the vehicle may damage
it. Always keep the covers on any
electrical component.

Chevrolet Trailblazer Owner Manual (GMNA-Localizing-U.S./Canada-
14400528) - 2021 - CRC - 11/7/19
Vehicle Care 303
The jump start negative terminal (3) and
positive terminal (4) are on the battery of
the vehicle providing the jump start.
The positive jump start connection for the
discharged battery is under a trim cover.
Open the cover to expose the terminal.1. Check the other vehicle. It must have a 12-volt battery with a negative ground
system.
Caution
If the other vehicle does not have a
12-volt system with a negative ground,
both vehicles can be damaged. Only use
a vehicle that has a 12-volt system with a
negative ground for jump starting.
2. Position the two vehicles so that they are not touching.
3. Set the parking brake firmly and put the shift lever in P (Park) with an automatic
transmission, or Neutral with a manual
transmission.
Caution
If any accessories are left on or plugged
in during the jump starting procedure,
they could be damaged. The repairs
would not be covered by the vehicle
warranty. Whenever possible, turn off or
unplug all accessories on either vehicle
when jump starting.
4. Turn the ignition off. Turn off all lights and accessories in both vehicles, except
the hazard warning flashers if needed.
{Warning
An electric fan can start up even when
the engine is not running and can injure
you. Keep hands, clothing, and tools
away from any underhood electric fan.
{Warning
Using a match near a battery can cause
battery gas to explode. People have been
hurt doing this, and some have been
blinded. Use a flashlight if you need
more light.
(Continued)
Warning (Continued)
Battery fluid contains acid that can burn
you. Do not get it on you. If you
accidentally get it in your eyes or on
your skin, flush the place with water and
get medical help immediately.
{Warning
Fans or other moving engine parts can
injure you badly. Keep your hands away
from moving parts once the engine is
running.
5. Connect one end of the red positive (+) cable to the positive (+) terminal on the
discharged battery.
6. Connect the other end of the red positive (+) cable to the positive (+)
terminal of the good battery.
7. Connect one end of the black negative (–) cable to the negative (–)
terminal of the good battery.
8. Connect the other end of the black negative (–) cable to the negative (–)
grounding point for the discharged
battery.

Chevrolet Trailblazer Owner Manual (GMNA-Localizing-U.S./Canada-
14400528) - 2021 - CRC - 11/7/19
310 Vehicle Care
snow and ice. If the check engine light is
activated, please check to see if the shutter
system is clear of debris, snow or ice.
Windshield and Wiper Blades
Clean the outside of the windshield with
glass cleaner.
Clean rubber blades using a lint-free cloth or
paper towel soaked with windshield washer
fluid or a mild detergent. Wash the
windshield thoroughly when cleaning the
blades. Bugs, road grime, sap, and a buildup
of vehicle wash/wax treatments may cause
wiper streaking.
Replace the wiper blades if they are worn or
damaged. Damage can be caused by
extreme dusty conditions, sand, salt, heat,
sun, snow, and ice.
Weatherstrips
Apply weatherstrip lubricant on
weatherstrips to make them last longer, seal
better, and not stick or squeak. Lubricate
weatherstrips at least once a year. Hot, dry
climates may require more frequent
application. Black marks from rubber
material on painted surfaces can be removed
by rubbing with a clean cloth. See
Recommended Fluids and Lubricants0325.
Tires
Use a stiff brush with tire cleaner to clean
the tires.
Caution
Using petroleum-based tire dressing
products on the vehicle may damage the
paint finish and/or tires. When applying a
tire dressing, always wipe off any
overspray from all painted surfaces on
the vehicle.
Wheels and Wheel Trim
Use a soft, clean cloth with mild soap and
water to clean the wheels. After rinsing
thoroughly with clean water, dry with a
soft, clean towel. A wax may then be
applied.
Caution
Chrome wheels and chrome wheel trim
may be damaged if the vehicle is not
washed after driving on roads that have
been sprayed with magnesium chloride or
calcium chloride. These are used on roads
for conditions such as dust and ice.
Always wash the chrome with soap and
water after exposure.
Caution
To avoid surface damage on wheels and
wheel trim, do not use strong soaps,
chemicals, abrasive polishes, cleaners,
or brushes. Use only GM approved
cleaners. Do not drive the vehicle through
an automatic car wash that uses silicon
carbide tire/wheel cleaning brushes.
Damage could occur and the repairs
would not be covered by the vehicle
warranty.
Brake System
Visually inspect brake lines and hoses for
proper attachment, connections, binding,
leaks, cracks, chafing, etc. Inspect disc brake
pads for wear and rotors for surface
condition. Inspect drum brake linings/shoes
for wear or cracks. Inspect all other brake
parts.
Steering, Suspension, and Chassis
Components
Visually inspect steering, suspension, and
chassis components for damaged, loose,
or missing parts or signs of wear at least
once a year.

Chevrolet Trailblazer Owner Manual (GMNA-Localizing-U.S./Canada-
14400528) - 2021 - CRC - 11/7/19
316 Service and Maintenance
Because of the way people use vehicles,
maintenance needs vary. There may need to
be more frequent checks and services. The
Additional Required Services - Normal are for
vehicles that:
.Carry passengers and cargo within
recommended limits on the Tire and
Loading Information label. SeeVehicle
Load Limits 0187.
.Are driven on reasonable road surfaces
within legal driving limits.
.Use the recommended fuel. See
Recommended Fuel 0231.
Refer to the information in the Maintenance
Schedule Additional Required Services -
Normal chart.
The Additional Required Services - Severe are
for vehicles that are:
.Mainly driven in heavy city traffic in hot
weather.
.Mainly driven in hilly or mountainous
terrain.
.Frequently towing a trailer.
.Used for high speed or competitive
driving.
.Used for taxi, police, or delivery service. Refer to the information in the Maintenance
Schedule Additional Required Services -
Severe chart.
{Warning
Performing maintenance work can be
dangerous and can cause serious injury.
Perform maintenance work only if the
required information, proper tools, and
equipment are available. If they are not,
see your dealer to have a trained
technician do the work. See
Doing Your
Own Service Work 0245.
Maintenance Schedule
Owner Checks and Services
Check the engine oil level. See Engine Oil
0 250.
Once a Month
.Check the tire inflation pressures. See Tire
Pressure 0285.
.Inspect the tires for wear. See Tire
Inspection 0290.
.Check the windshield washer fluid level.
See Washer Fluid 0259.
Engine Oil Change
When the CHANGE ENGINE OIL SOON DIC
message displays, have the engine oil and
filter changed within the next 1 000 km
(600 mi). If driven under the best conditions,
the engine oil life system may not indicate
the need for vehicle service for up to a year.
The engine oil and filter must be changed at
least once a year and the oil life system
must be reset. Your trained dealer technician
can perform this work. If the engine oil life
system is reset accidentally, service the
vehicle within 5 000 km (3,000 mi) since the
last service. Reset the oil life system when
the oil is changed. See Engine Oil Life
System 0252.
Air Conditioning Desiccant (Replace Every
Seven Years)
The air conditioning system requires
maintenance every seven years. This service
requires replacement of the desiccant to
help the longevity and efficient operation of
the air conditioning system. This service can
be complex. See your dealer.

Chevrolet Trailblazer Owner Manual (GMNA-Localizing-U.S./Canada-
14400528) - 2021 - CRC - 11/7/19
Service and Maintenance 317
Engine Air Filter Change
When the REPLACE AT NEXT OIL CHANGE
message displays, the engine air filter
should be replaced at the next engine oil
change. When the REPLACE ENGINE AIR
FILTER SOON message displays, the engine
air filter should be replaced at the earliest
convenience. Reset the engine air filter life
system after the engine air filter is replaced.
SeeEngine Air Filter Life System 0253.
Tire Rotation and Required Services
Every 12 000 km (7,500 mi)
Rotate the tires, if recommended for the
vehicle, and perform the following services.
See Tire Rotation 0290.
.Check engine oil level and oil
life percentage. If needed, change engine
oil and filter, and reset oil life system.
See Engine Oil 0250 and
Engine Oil Life System 0252.
.If equipped with the engine air filter life
system, check the air filter
life percentage. If necessary, replace the
engine air filter and reset the engine air
filter life system. See Engine Air Filter Life
System. If the vehicle is not equipped
with the engine air filter life system,
inspect the engine air cleaner filter. See
Engine Air Cleaner/Filter 0253.
.Check engine coolant level. See Cooling
System 0255.
.Check windshield washer fluid level. See
Washer Fluid 0259.
.Check tire inflation pressures. See Tire
Pressure 0285.
.Inspect tire wear. See Tire Inspection
0 290.
.Visually check for fluid leaks.
.Inspect brake system. See Exterior Care
0 307.
.Visually inspect steering, suspension, and
chassis components for damage, including
cracks or tears in the rubber boots, loose
or missing parts, or signs of wear at least
once a year. See Exterior Care0307.
.Inspect power steering for proper
attachment, connections, binding, leaks,
cracks, chafing, etc.
.Visually inspect halfshafts and driveshafts
for excessive wear, lubricant leaks, and/or
damage including: tube dents or cracks,
constant velocity joint or universal joint
looseness, cracked or missing boots, loose
or missing boot clamps, center bearing
excessive looseness, loose or missing
fasteners, and axle seal leaks.
.Check restraint system components. See
Safety System Check 050.
.Visually inspect fuel system for damage
or leaks.

Chevrolet Trailblazer Owner Manual (GMNA-Localizing-U.S./Canada-
14400528) - 2021 - CRC - 11/7/19
Service and Maintenance 319
Maintenance Schedule Additional
Required Services - Normal12 000 km/7,500 mi
24 000 km/15,000 mi
36 000 km/22,500 mi
48 000 km/30,000 mi 60 000 km/37,500 mi
72 000 km/45,000 mi84 000 km/52,500 mi
96 000 km/60,000 mi
108 000 km/67,500 mi 120 000 km/75,000 mi 132 000 km/82,500 mi
144 000 km/90,000 mi 156 000 km/97,500 mi
168 000 km/105,000 mi 180 000 km/112,500 mi
192 000 km/120,000 mi 204 000 km/127,500 mi 216 000 km/135,000 mi
228 000 km/142,500 mi
240 000 km/150,000 mi
Rotate tires and perform Required Services. Check engine oil
level and oil life percentage. Change engine oil and filter,
if needed.
Check engine air filter life percentage and status. Change
engine air filter, if needed. (1)
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
Replace passenger compartment air filter. (2)@ @@@@@
Inspect evaporative control system. (3)@ @@
Replace spark plugs. Inspect spark plug wires and/or boots.@ @
Change rear axle fluid, if equipped with AWD. (4)@
Drain and fill engine cooling system. (5)@
Visually inspect accessory drive belts. (6)@
Replace brake fluid. (7)
Replace windshield wiper blades. (8)
@ @ @ @ @ @ @ @ @ @
Replace hood and/or body lift support gas struts. (9)@ @
Replace air conditioning desiccant. (10)
Replace oil pump drive belt and timing belt. (LIH 1.2L L3
Engine Only). (11)
@

Chevrolet Trailblazer Owner Manual (GMNA-Localizing-U.S./Canada-
14400528) - 2021 - CRC - 11/7/19
320 Service and Maintenance
Footnotes—Maintenance Schedule
Additional Required Services - Normal
(1) Or every four years, whichever comes
first. If driving in dusty conditions, inspect
the filter at each oil change or more often
as needed. See Engine Air Cleaner/Filter
0 253.
(2) Or every two years, whichever comes
first. More frequent passenger compartment
air filter replacement may be needed if
driving in areas with heavy traffic, poor air
quality, high dust levels, or environmental
allergens. Passenger compartment air filter
replacement may also be needed if there is
reduced airflow, window fogging, or odors.
Your GM dealer can help determine when to
replace the filter. (3)
Visually check all fuel and vapor lines
and hoses for proper attachment,
connection, routing, and condition.
(4) Do not directly power wash the transfer
case and/or front/rear axle output seals.
High pressure water can overcome the seals
and contaminate the transfer case fluid.
Contaminated fluid will decrease the life of
the transfer case and/or axles and should be
replaced.
(5) Or every five years, whichever comes
first. See Cooling System 0255.
(6) Or every 10 years, whichever comes first.
Inspect for fraying, excessive cracking,
or damage; replace, if needed. (7)
Replace brake fluid every five years. See
Brake Fluid 0260.
(8) Or every 12 months, whichever comes
first. See Wiper Blade Replacement 0264.
(9) Or every 10 years, whichever comes first.
See Gas Strut(s) 0265.
(10) Replace air conditioning desiccant every
seven years.
(11) The oil pump drive belt and the timing
belt on the LIH engine must be replaced at
150,000 miles (240,000 km) or 15 years,
whichever comes first.

Chevrolet Trailblazer Owner Manual (GMNA-Localizing-U.S./Canada-
14400528) - 2021 - CRC - 11/7/19
Service and Maintenance 321
Maintenance Schedule Additional
Required Services - Severe12 000 km/7,500 mi
24 000 km/15,000 mi
36 000 km/22,500 mi
48 000 km/30,000 mi 60 000 km/37,500 mi
72 000 km/45,000 mi84 000 km/52,500 mi
96 000 km/60,000 mi
108 000 km/67,500 mi 120 000 km/75,000 mi 132 000 km/82,500 mi
144 000 km/90,000 mi 156 000 km/97,500 mi
168 000 km/105,000 mi 180 000 km/112,500 mi
192 000 km/120,000 mi 204 000 km/127,500 mi 216 000 km/135,000 mi
228 000 km/142,500 mi
240 000 km/150,000 mi
Rotate tires and perform Required Services. Check engine oil
level and oil life percentage. Change engine oil and filter,
if needed.
Check engine air filter life percentage and status. Change
engine air filter, if needed. (1)
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
Replace passenger compartment air filter. (2)@ @@@@@
Inspect evaporative control system. (3)@ @@
Change automatic transmission fluid. (9 Speed
Transmission Only)@@@
Change automatic transmission fluid and filter. (Continuously
Variable Ratio Transmission (CVT) Only)@@@
Replace spark plugs. Inspect spark plug wires and/or boots.@ @
Change rear axle fluid, if equipped with AWD. (4)@ @
Drain and fill engine cooling system. (5)@
Visually inspect accessory drive belts. (6)@
Replace brake fluid. (7)
Replace windshield wiper blades. (8)
@ @ @ @ @ @ @ @ @ @
Replace hood and/or body lift support gas struts. (9)@@
Replace air conditioning desiccant. (10)
Replace oil pump drive belt and timing belt. (LIH 1.2L L3
Engine Only). (11)
@