2021 GMC TERRAIN check engine

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
334 Service and Maintenance
Footnotes—Maintenance Schedule
Additional Required Services - Normal
(1) 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.
(2) Visually check all fuel and vapor lines
and hoses for proper attachment,
connection, routing, and condition. (3)
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
0 265.
(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 0267. (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 0272.
(8) Or every 12 months, whichever comes
first. See Wiper Blade Replacement 0275.
(9) Or every 10 years, whichever comes first.
See Gas Strut(s) 0276.
(10) Replace air conditioning desiccant every
seven years.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
Service and Maintenance 335
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.
If equipped, check engine air filter life percentage and status.
Change engine air filter, if needed.
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
Replace passenger compartment air filter. (1)@ @@@@@
Inspect evaporative control system. (2)@ @@
If the vehicle is not equipped with the engine air filter life
system, replace engine air cleaner filter. (3)@@@
Change automatic transmission fluid.@@@
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 front and rear wiper blades. (8)
@ @ @ @ @ @ @ @ @ @
Replace hood and/or body lift support gas struts. (9)@@
Replace air conditioning desiccant. (10)

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
336 Service and Maintenance
Footnotes—Maintenance Schedule
Additional Required Services - Severe
(1) 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.
(2) Visually check all fuel and vapor lines
and hoses for proper attachment,
connection, routing, and condition.
(3) 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
0 265.
(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 0267.
(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 0272.
(8) Or every 12 months, whichever comes
first. See Wiper Blade Replacement 0275.
(9) Or every 10 years, whichever comes first.
See Gas Strut(s) 0276.
(10) Replace air conditioning desiccant every
seven years.
Special Application Services
.Severe Commercial Use Vehicles Only:
Lubricate chassis components every oil
change.
.Have underbody flushing service
performed. See "Underbody Maintenance"
in Exterior Care 0322.
Additional Maintenance
and Care
Your vehicle is an important investment and
caring for it properly may help to avoid
future costly repairs. To maintain vehicle
performance, additional maintenance
services may be required.
It is recommended that your dealer perform
these services —their trained dealer
technicians know your vehicle best. Your
dealer can also perform a thorough
assessment with a multi-point inspection to
recommend when your vehicle may need
attention.
The following list is intended to explain the
services and conditions to look for that may
indicate services are required.
Battery
The 12-volt battery supplies power to start
the engine and operate any additional
electrical accessories.
.To avoid break-down or failure to start
the vehicle, maintain a battery with full
cranking power.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
Service and Maintenance 337
.Trained dealer technicians have the
diagnostic equipment to test the battery
and ensure that the connections and
cables are corrosion-free.
Belts
.Belts may need replacing if they squeak
or show signs of cracking or splitting.
.Trained dealer technicians have access to
tools and equipment to inspect the belts
and recommend adjustment or
replacement when necessary.
Brakes
Brakes stop the vehicle and are crucial to
safe driving.
.Signs of brake wear may include chirping,
grinding, or squealing noises, or difficulty
stopping.
.Trained dealer technicians have access to
tools and equipment to inspect the brakes
and recommend quality parts engineered
for the vehicle.
Fluids
Proper fluid levels and approved fluids
protect the vehicle’s systems and
components. See Recommended Fluids and
Lubricants 0339 for GM approved fluids.
.Engine oil and windshield washer fluid
levels should be checked at every fuel fill.
.Instrument cluster lights may come on to
indicate that fluids may be low and need
to be filled.
Hoses
Hoses transport fluids and should be
regularly inspected to ensure that there are
no cracks or leaks. With a multi-point
inspection, your dealer can inspect the hoses
and advise if replacement is needed.
Lamps
Properly working headlamps, taillamps, and
brake lamps are important to see and be
seen on the road.
.Signs that the headlamps need attention
include dimming, failure to light, cracking,
or damage. The brake lamps need to be
checked periodically to ensure that they
light when braking.
.With a multi-point inspection, your dealer
can check the lamps and note any
concerns. Shocks and Struts
Shocks and struts help aid in control for a
smoother ride.
.Signs of wear may include steering wheel
vibration, bounce/sway while braking,
longer stopping distance, or uneven
tire wear.
.As part of the multi-point inspection,
trained dealer technicians can visually
inspect the shocks and struts for signs of
leaking, blown seals, or damage, and can
advise when service is needed.
Tires
Tires need to be properly inflated, rotated,
and balanced. Maintaining the tires can save
money and fuel, and can reduce the risk of
tire failure.
.Signs that the tires need to be replaced
include three or more visible treadwear
indicators; cord or fabric showing through
the rubber; cracks or cuts in the tread or
sidewall; or a bulge or split in the tire.
.Trained dealer technicians can inspect and
recommend the right tires. Your dealer
can also provide tire/wheel balancing
services to ensure smooth vehicle
operation at all speeds. Your dealer sells
and services name brand tires.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
344 Technical Data
ApplicationCapacities
Metric English
All capacities are approximate. When adding, be sure to fill to the approximate level, as recommended in this manual. Recheck fluid level
after filling.
*Engine cooling system capacity values are based on the entire cooling system and its components.
Engine Specifications
Engine VIN CodeTransmission Spark Plug Gap
1.5L L4 Gas Engine (LYX) VAutomatic0.60–0.70 mm (0.024–0.028 in)
Spark plug gaps are preset by the manufacturer. Re-gapping the spark plug is not recommended and can damage the spark plug.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
358 OnStar
.Receive a Diagnostic check of the vehicle's
key operating systems.
.Receive Roadside Assistance.
.Manage Wi-Fi Settings, if equipped.
Press
>to get a priority connection to an
OnStar Advisor available 24/7 to:
.Get help for an emergency.
.Be a Good Samaritan or respond to an
AMBER Alert.
.Get assistance in severe weather or other
crisis situations and find evacuation
routes.
OnStar Services
Emergency
Emergency Services require an active safety
and security plan. With Automatic Crash
Response, built-in sensors can automatically
alert a specially trained OnStar Advisor who
is immediately connected in to the vehicle
to help.
Press
>for a priority connection to an
OnStar Advisor who can contact emergency
service providers, direct them to your exact
location, and relay important information. With OnStar Crisis Assist, specially trained
Advisors are available 24 hours a day, 7 days
a week, to provide a central point of
contact, assistance, and information during a
crisis.
With Roadside Assistance, Advisors can
locate a nearby service provider to help with
a flat tire, a battery jump, or an empty
gas tank.
Security
If equipped, OnStar provides these services:
.With Stolen Vehicle Assistance, OnStar
Advisors can use GPS to pinpoint the
vehicle and help authorities quickly
recover it.
.With Remote Ignition Block, if equipped,
OnStar can block the engine from being
restarted.
.With Stolen Vehicle Slowdown,
if equipped, OnStar can work with law
enforcement to gradually slow the
vehicle down.
Theft Alarm Notification
If equipped, if the doors are locked and the
vehicle alarm sounds, a notification by text,
e-mail, or phone call will be sent. If the
vehicle is stolen, an OnStar Advisor can work
with authorities to recover the vehicle.
OnStar Additional
Information
In-Vehicle Audio Messages
Audio messages may play important
information at the following times:
.Prior to vehicle purchase. PressQto set
up an account.
.After change in ownership and at
90 days.
Transferring Service
PressQto request account transfer
eligibility information. The Advisor can
cancel or change account information.
Selling/Transferring the Vehicle
Call 1-888-4ONSTAR (1-888-466-7827)
immediately to terminate your OnStar or
connected services if the vehicle is disposed
of, sold, transferred, or if the lease ends.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/-
Mexico-14420055) - 2021 - CRC - 11/13/20
Index 365
IndexA
About Driving the Vehicle . . . . . . . . . . . . . . . . . .2
Accessories and Modifications . . . . . . . . . . . 258
Accessory Power . . . . . . . . . . . . . . . . . . . . . . . . . 204
Adaptive Cruise Control . . . . . . . . . . . . . . . . . . 222
Add-On Electrical Equipment . . . . . . . . . . . . . 256
Additional InformationOnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 358
Additional Maintenance and Care . . . . . . . . 336
Adjustments Lumbar, Front Seats . . . . . . . . . . . . . . . . . . . . 32
Agreements Trademarks and License . . . . . . . . . . . . . . . 169
Air Cleaner/Filter, Engine . . . . . . . . . . . . . . . . 265
Air Conditioning . . . . . . . . . . . . . . . . . . . . . 178, 180
Air Filter
Life System . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265
Air Filter, Passenger Compartment . . . . . . . .182
Air Vents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .182
Airbag System Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
How Does an Airbag Restrain? . . . . . . . . . . . 51
Passenger Sensing System . . . . . . . . . . . . . . 52
What Makes an Airbag Inflate? . . . . . . . . . 50
What Will You See after an AirbagInflates? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
When Should an Airbag Inflate? . . . . . . . . 50
Where Are the Airbags? . . . . . . . . . . . . . . . . 48 Airbags
Adding Equipment to the Vehicle . . . . . . . 56
Passenger Status Indicator . . . . . . . . . . . . . . 92
Readiness Light . . . . . . . . . . . . . . . . . . . . . . . . . 92
Servicing Airbag-Equipped Vehicles . . . . . . 55
System Check . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Alarm
Vehicle Security . . . . . . . . . . . . . . . . . . . . . . . . 22
Alert Lane Change . . . . . . . . . . . . . . . . . . . . . . . . . . . 242
Side Blind Zone (SBZA) . . . . . . . . . . . . . . . . . 242
All-Season Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 287
All-Wheel Drive . . . . . . . . . . . . . . . . . . . . . . 212, 274
AM-FM Radio . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Antenna Multi-band . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
Antilock Brake System (ABS) . . . . . . . . . . . . . . 212 Warning Light . . . . . . . . . . . . . . . . . . . . . . . . . . 96
Appearance Care Exterior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
Interior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326
Apple CarPlay and Android Auto . . . . . . . . . 160
Assistance Program, Roadside . . . . . . . . . . . . 349
Assistance Systems for Driving . . . . . . . . . . 237
Assistance Systems for Parking and Backing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232
Audio Bluetooth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/-
Mexico-14420055) - 2021 - CRC - 11/13/20
366 Index
Auto StopStop/Start System . . . . . . . . . . . . . . . . . . . . . 201
Automatic Dimming Mirrors . . . . . . . . . . . . . . . . . . . . . . . 25
Door Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Emergency Braking (AEB) . . . . . . . . . . . . . . 239
Headlamp System . . . . . . . . . . . . . . . . . . . . . . 118
Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . 208
Transmission Fluid . . . . . . . . . . . . . . . . . . . . . 265
Automatic Transmission Manual Mode . . . . . . . . . . . . . . . . . . . . . . . . . . 211
Avoiding Untrusted Media Devices . . . . . . . .134
B
Battery Exterior Lighting Battery Saver . . . . . . . . 122
Load Management . . . . . . . . . . . . . . . . . . . . . . 121
Power Protection . . . . . . . . . . . . . . . . . . . . . . 122
Battery - North America . . . . . . . . . . . . . 273, 316
Blade Replacement, Wiper . . . . . . . . . . . . . . . 275
Bluetooth Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 155, 156
Bluetooth Audio . . . . . . . . . . . . . . . . . . . . . . . . . 136
Brake Parking, Electric . . . . . . . . . . . . . . . . . . . . . . . . 212
System Warning Light . . . . . . . . . . . . . . . . . . 95
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271 Antilock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212 Brakes (cont'd)
Assist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214
Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272
Braking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188 Automatic Emergency (AEB) . . . . . . . . . . . 239
Braking System Front Pedestrian (FPB) . . . . . . . . . . . . . . . . . 240
Break-In, New Vehicle . . . . . . . . . . . . . . . . . . . . 199
Bulb Replacement Front Turn Signal Lamps . . . . . . . . . . . . . . . 278
Halogen Bulbs . . . . . . . . . . . . . . . . . . . . . . . . . 277
Headlamp Aiming . . . . . . . . . . . . . . . . . . . . . . 277
Headlamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
High Intensity Discharge (HID)Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
License Plate Lamps . . . . . . . . . . . . . . . . . . . 279
Taillamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278
Buying New Tires . . . . . . . . . . . . . . . . . . . . . . . . 300
C
Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .81
California Perchlorate Materials Requirements . . . 258
California Proposition 65 Warning . . . . . . . . . . . . . . . . . . .258, 273, 316, Back Cover
Canadian Vehicle Owners . . . . . . . . . . . . . . . . . . . 1
Capacities and Specifications . . . . . . . . . . . . . 343 Carbon Monoxide
Engine Exhaust . . . . . . . . . . . . . . . . . . . . . . . . 207
Liftgate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Winter Driving . . . . . . . . . . . . . . . . . . . . . . . . . 194
Cargo Cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Tie-Downs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Caution, Danger, and Warning . . . . . . . . . . . . . .2
Center Console Storage . . . . . . . . . . . . . . . . . . . .75
Chains, Tire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303
Charging Wireless . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
Charging System Light . . . . . . . . . . . . . . . . . . . . 93
Check Engine Light (Malfunction Indicator) . . . . 93
Child Restraints
Infants and Young Children . . . . . . . . . . . . . 58
Lower Anchors and Tethers forChildren . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Older Children . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Securing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69, 70
Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Circuit Breakers . . . . . . . . . . . . . . . . . . . . . . . . . . 280
Cleaning Exterior Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
Interior Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 326
Climate Control Systems . . . . . . . . . . . . . . . . . .178 Air Conditioning . . . . . . . . . . . . . . . . . . . . . . . 178