2020 GMC TERRAIN wiring

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/4/19
Seats and Restraints 69
{Warning
For up to 10 seconds after the
vehicle is turned off and the
battery is disconnected, an airbag
can still inflate during improper
service. You can be injured if you
are close to an airbag when it
inflates. Avoid yellow connectors.
They are probably part of the
airbag system. Be sure to follow
proper service procedures, and
make sure the person performing
work for you is qualified to do so.
Adding Equipment to the
Airbag-Equipped Vehicle
Adding accessories that change the
vehicle's frame, bumper system,
height, front end, or side sheet
metal may keep the airbag system
from working properly.
The operation of the airbag system
can also be affected by changing,
including improperly repairing or
replacing, any parts of the following:.
Airbag system, including airbag
modules, front or side impact
sensors, sensing and diagnostic
module, or airbag wiring
. Front seats, including stitching,
seams or zippers
. Seat belts
. Steering wheel, instrument
panel, overhead console, ceiling
trim, or pillar garnish trim
. Inner door seals, including
speakers
Your dealer and the service manual
have information about the location
of the airbag modules and sensors,
sensing and diagnostic module, and
airbag wiring along with the proper
replacement procedures.
In addition, the vehicle has a
passenger sensing system for the
front outboard passenger position,
which includes sensors that are part
of the passenger seat. The
passenger sensing system may not
operate properly if the original seat
trim is replaced with non-GM
covers, upholstery, or trim; or with GM covers, upholstery, or trim
designed for a different vehicle. Any
object, such as an aftermarket seat
heater or a comfort-enhancing pad
or device, installed under or on top
of the seat fabric, could also
interfere with the operation of the
passenger sensing system. This
could either prevent proper
deployment of the passenger
airbag(s) or prevent the passenger
sensing system from properly
turning off the passenger airbag(s).
See
Passenger Sensing System
0 64.
If the vehicle has rollover roof-rail
airbags, see Different Size Tires
and Wheels 0331 for additional
important information.
If the vehicle must be modified
because you have a disability and
have questions about whether the
modifications will affect the vehicle's
airbag system, or if you have
questions about whether the airbag
system will be affected if the vehicle
is modified for any other reason, call
Customer Assistance. See
Customer Assistance Offices 0387.

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/4/19
Instruments and Controls 113
Seat Belt Reminders
Driver Seat Belt Reminder
Light
There is a driver seat belt reminder
light on the instrument cluster.
When the vehicle is started, this
light flashes and a chime may come
on to remind the driver to fasten
their seat belt. Then the light stays
on solid until the belt is buckled.
This cycle may continue several
times if the driver remains or
becomes unbuckled while the
vehicle is moving.
If the driver seat belt is buckled,
neither the light nor the chime
comes on.
Passenger Seat Belt Reminder
Light
There is a passenger seat belt
reminder light near the passenger
airbag status indicator. See
Passenger Sensing System064.
When the vehicle is started, this
light flashes and a chime may come
on to remind passengers to fasten
their seat belt. Then the light stays
on solid until the belt is buckled.
This cycle continues several times if
the passenger remains or becomes
unbuckled while the vehicle is
moving.
If the passenger seat belt is
buckled, neither the chime nor the
light comes on.
The front passenger seat belt
reminder light and chime may turn
on if an object is put on the seat such as a briefcase, handbag,
grocery bag, laptop, or other
electronic device. To turn off the
reminder light and/or chime, remove
the object from the seat or buckle
the seat belt.
Airbag Readiness Light
This light shows if there is an
electrical problem with the airbag
system. The system check includes
the airbag sensor(s), the passenger
sensing system, the pretensioners,
the airbag modules, the wiring, and
the crash sensing and diagnostic
module. For more information on the
airbag system, see
Airbag System
0 58.

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/5/19
Vehicle Care 289
replace if damaged. Do not clean
the engine air cleaner/filter or
components with water or
compressed air.
To inspect or replace the engine air
cleaner/filter:
1.5L Gas Engine Shown, 1.6LDiesel Engine and 2.0L Gas Engine Similar
1. Screws
2. Air Duct Clamp
3. Electrical Connector
1. Open the hood. See Hood
0 276.
2. Loosen the screw on the air duct clamp (2) and remove the
air duct hose from the cover.
3. Remove the four screws (1) and remove the air cleaner/
filter cover, keeping the wiring
harness electrical connector (3)
connected to the sensor.
4. Pull straight up on the cover, and while holding the cover,
remove the air cleaner/filter.
5. Inspect or replace the air cleaner/filter.How to Reinstall the Engine
Air Cleaner/Filter
1. Align the air cleaner/filter withthe indicated point on the base
of the air cleaner/filter housing
and install the air cleaner/filter.
The outer air cleaner/filter seal
must be fitted properly in the
air cleaner/filter housing.
2. Align the air cleaner/filter housing cover tabs to the air
cleaner/filter housing.
3. Install the air cleaner/filter housing cover using the four
screws.

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/5/19
290 Vehicle Care
4. Slide the air duct onto thecover assembly and tighten the
screw on the air duct clamp.
5. Verify that the wiring harness connector is fully connected to
the sensor on the air cleaner/
filter housing.
{Warning
Operating the engine with the air
cleaner/filter off can cause you or
others to be burned. Use caution
when working on the engine. Do
not start the engine or drive the
vehicle with the air cleaner/filter
off, as flames may be present if
the engine backfires.
Caution
If the air cleaner/filter is off, dirt
can easily get into the engine,
which could damage it. Always
have the air cleaner/filter in place
when driving.
Cooling System
1.5L Gas Engine
1. Engine Cooling Fan (Out
of View)
2. Engine Coolant Surge Tank and Pressure Cap
1.6L Diesel Engine
1. Engine Cooling Fan (Out
of View)
2. Engine Coolant Surge Tank and Pressure Cap

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/5/19
Vehicle Care 305
2. Remove the two screw capsand two screws from the
taillamp assembly.
3. Pull the taillamp assembly out of the vehicle body.
4. Disconnect the lamp wiring harness.5. Turn the bulb socketcounterclockwise and pull
it out.
6. Pull the bulb straight out of the socket.
7. Push the replacement bulb straight into the bulb socket.
8. Push the bulb socket in and turn it clockwise.
9. Reverse Steps 2–5 to reinstall the lamp assembly.
License Plate Lamp
Lamp Assembly
Bulb Assembly

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/5/19
306 Vehicle Care
1. Bulb Socket
2. Bulb
3. Lamp Assembly
To replace one of these bulbs:1. Open the liftgate partway. See Liftgate 021.
2. Push the lamp assembly outboard to remove.
3. Pull the lamp assembly down to remove it from the liftgate.
4. Turn the bulb socket (1) counterclockwise to remove it
from the lamp assembly (3).
5. Pull the bulb (2) straight out of the bulb socket (1).
6. Push the replacement bulb straight into the bulb socket
and turn the bulb socket
clockwise to install it into the
lamp assembly.
7. Push the lamp assembly into the liftgate engaging the clip
side first.
8. Push on the lamp side opposite the clip until the lamp assembly
snaps into place.
Electrical System
Electrical System
Overload
The vehicle has fuses and circuit
breakers to protect against an
electrical system overload.
When the electrical load current is
too heavy, the circuit breaker opens
and closes, protecting the circuit
until the current load returns to
normal or the problem is fixed. This
greatly reduces the chance of circuit
overload and fire caused by
electrical problems.
Replace a bad fuse with a new one
of the identical size and rating.
If there is a problem on the road and
a fuse needs to be replaced, the
same amperage fuse can be
borrowed. Choose some feature of
the vehicle that is not needed to use
and replace it as soon as possible.
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.

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/5/19
Vehicle Care 307
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.
There is a fuse puller in the engine
compartment fuse block. See
Engine Compartment Fuse Block
0
307. It can be used to easily
remove fuses from the fuse block.
To identify and check fuses, circuit
breakers, and relays see Engine
Compartment Fuse Block 0307 or
Instrument Panel Fuse Block 0310
and
Rear Compartment Fuse Block
0 312.
Engine Compartment
Fuse Block
To remove the fuse block cover,
squeeze the clips on the cover and
lift it straight up. See Engine
Compartment Overview 0278.
Caution
Spilling liquid on any electrical
component on the vehicle may
damage it. Always keep the
covers on any electrical
component.