ECU GMC TERRAIN 2020 Service Manual

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/4/19
140 Instruments and Controls
Seat Entry Memory
This feature automatically recalls
the previously stored 1 or 2 button
positions when the ignition is
changed from off to on or ACC/
ACCESSORY. SeeMemory Seats
0 41.
Touch Off or On.
Seat Exit Memory
This feature automatically recalls
the previously stored exit button
positions when the ignition is
changed from on or ACC/
ACCESSORY to off if the driver
door is open or opened. See
Memory Seats 041.
Touch Off or On.
Teen Driver
See “Teen Driver” under“Settings”
in the infotainment manual.
Valet Mode
This will lock the infotainment
system and steering wheel controls.
It may also limit access to vehicle
storage locations, if equipped.
To enable valet mode:
1. Enter a four-digit code on the keypad.
2. Select Enter to go to the confirmation screen.
3. Re-enter the four-digit code.
Touch Lock or Unlock to lock or
unlock the system. Touch Back to
go back to the previous menu.
Universal Remote
System
See Radio Frequency Statement
0 395.
Universal Remote System
Programming
If equipped, these buttons are in the
overhead console.
This system can replace up to three
remote control transmitters used to
activate devices such as garage
door openers, security systems, and
home automation devices. These

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/4/19
Climate Controls 159
2. Disconnect the glove box doordamper (1) from the glove box
door assembly by squeezing
the pivot (2) to release the
damper ring.3. Squeeze both sides of theglove box bin inward to lower
beyond the stops.
4. Remove the two screwssecuring the door.
5. Press the latches on either side of the service door inward to
release. Open the service door
and remove the old filter.
6. Install the new air filter.
7. Close the service door completely.
8. Reverse the steps to reinstall the glove box.
See your dealer if additional
assistance is needed.
Service
All vehicles have a label underhood
that identifies the refrigerant used in
the vehicle. The refrigerant system
should only be serviced by trained
and certified technicians. The air
conditioning evaporator should
never be repaired or replaced by
one from a salvage vehicle.
It should only be replaced by a new
evaporator to ensure proper and
safe operation.

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/4/19
168 Driving and Operating
{Warning
When driving off-road, bouncing
and quick changes in direction
can easily throw you out of
position. This could cause you to
lose control and crash. You and
your passengers should always
wear seat belts.
Before Driving Off-Road
.Have all necessary maintenance
and service work completed.
. Fuel the vehicle, fill fluid levels,
and check inflation pressure in
all tires, including the spare,
if equipped.
. Read all the information about
all-wheel-drive vehicles in this
manual.
. Make sure all underbody
shields, if equipped, are properly
attached.
. Know the local laws that apply to
off-road driving.
Loading the Vehicle for
Off-Road Driving
{Warning
.Unsecured cargo on the
load floor can be tossed
about when driving over
rough terrain. You or your
passengers can be struck
by flying objects. Secure the
cargo properly.
. Keep cargo in the cargo
area as far forward and as
low as possible. The
heaviest things should be
on the floor, forward of the
rear axle.
. Heavy loads on the roof
raise the vehicle's center of
gravity, making it more likely
to roll over. You can be
seriously or fatally injured if
the vehicle rolls over. Put
heavy loads inside the
cargo area, not on the roof. For more information about loading
the vehicle, see
Vehicle Load Limits
0 175.
Environmental Concerns
.
Always use established trails,
roads, and areas that have been
set aside for public off-road
recreational driving and obey all
posted regulations.
. Do not damage shrubs, flowers,
trees, or grasses or disturb
wildlife.
. Do not park over things that
burn. See Parking over Things
That Burn 0190.
Driving on Hills
Driving safely on hills requires good
judgment and an understanding of
what the vehicle can and cannot do.
{Warning
Many hills are simply too steep
for any vehicle. Driving up hills
can cause the vehicle to stall.
(Continued)

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/4/19
Driving and Operating 179
Warning (Continued)
.Never stack heavier
things, like suitcases,
inside the vehicle so that
some of them are above
the tops of the seats.
.Do not leave an
unsecured child restraint
in the vehicle.
.Secure loose items in the
vehicle.
.Do not leave a seat
folded down unless
needed.
Starting and
Operating
New Vehicle Break-In
Caution
The vehicle does not need an
elaborate break-in. But it will
perform better in the long run if
you follow these guidelines:. Do not drive at any one
constant speed, fast or slow,
for the first 800 km (500 mi).
Do not make full-throttle
starts. Avoid downshifting to
brake or slow the vehicle.
. Avoid making hard stops for
the first 300 km (200 mi) or
so. During this time the new
brake linings are not yet
broken in. Hard stops with
new linings can mean
premature wear and earlier
replacement. Follow this
(Continued)
Caution (Continued)
breaking-in guideline every
time you get new brake
linings.
Following break-in, engine speed
and load can be gradually
increased.
Ignition Positions
The vehicle has an electronic
keyless ignition with pushbutton
start.

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/4/19
Driving and Operating 187
Warning (Continued)
.Use a weatherproof,
heavy-duty, 15 amp-rated
extension cord if needed.
Failure to use the
recommended extension
cord in good operating
condition, or using a
damaged heater or
extension cord, could make
it overheat and cause a fire,
property damage, electric
shock, and injury.
. Do not operate the vehicle
with the heater cord
permanently attached to the
vehicle. Possible heater
cord and thermostat
damage could occur.
. While in use, do not let the
heater cord touch vehicle
parts or sharp edges. Never
close the hood on the
heater cord.
(Continued)
Warning (Continued)
.Before starting the vehicle,
unplug the cord, reattach
the cover to the plug, and
securely fasten the cord.
Keep the cord away from
any moving parts.
The length of time the heater should
remain plugged in depends on
several factors. Ask a dealer in the
area where you will be parking the
vehicle for the best advice on this.
Retained Accessory
Power (RAP)
When the ignition is turned from on
to off, the following features (if
equipped) will continue to function
for up to 10 minutes, or until the
driver door is opened. These
features will also work when the
ignition is in RUN or ACC/
ACCESSORY:
. Infotainment System .
Power Windows (during RAP
this functionality will be lost
when any door is opened)
. Sunroof (during RAP this
functionality will be lost when
any door is opened)
. Auxiliary Power Outlet
. Audio System
. OnStar System
Shifting Into Park
{Warning
It can be dangerous to get out of
the vehicle if the vehicle is not in
P (Park) with the parking brake
set. The vehicle can roll. If you
have left the engine running, the
vehicle can move suddenly. You
or others could be injured. To be
sure the vehicle will not move,
even when you are on fairly level
ground, use the steps that follow.
If you are pulling a trailer, see
Driving Characteristics and
Towing Tips 0262.

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/4/19
196 Driving and Operating
It is normal to hear the DEF system
purge fluid back into the tank after
the vehicle is shut off.
Locating Diesel Exhaust Fluid
DEF can be purchased at your
dealer. It can also be purchased at
authorized vehicle and truck
dealerships. Additionally, some
diesel truck fueling stations or
retailers may have DEF for
purchase. For vehicles with an
active OnStar or connected services
plan, OnStar can help to locate a
DEF retailer. SeeCustomer
Assistance Offices 0387 for phone
numbers to assist in contacting a
GM dealer. See Recommended
Fluids and Lubricants 0377. Filling the DEF Tank
Caution
Use only DEF that is GM
approved, or fluid containing the
API certified or ISO 22241 label.
The use of other fluids could
damage the system, requiring
costly repairs that will not be
covered by the vehicle warranty.
Caution
Do not mix fuel with DEF, and do
not put DEF in the fuel tank. This
could lead to costly repairs that
might not be covered by the
vehicle warranty.
It is recommended to fill the DEF
tank on level ground and when the
vehicle is not running. When adding
fluid, it is recommended to fill the
DEF tank.
Caution
Do not overfill the DEF tank and
do not allow DEF to contact the
finished surfaces of the vehicle,
as it could damage the vehicle
finish. If DEF is spilled during
filling, wipe any affected surface
with a damp cloth.
Do not top off the DEF tank. If using
a bottle or jug to refill DEF, follow
the instructions on the container
label and use a dedicated fill aid.

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/4/19
264 Driving and Operating
the combination by driving on a
level road surface before driving on
public roads.
The trailer structure, the tires, and
the brakes must be all be rated to
carry the intended cargo.
Inadequate trailer equipment can
cause the combination to operate in
an unexpected or unsafe manner.
Before driving, inspect all trailer
hitch parts and attachments, safety
chains, electrical connectors, lamps,
tires, and mirrors. SeeTowing
Equipment 0269. If the trailer has
electric brakes, start the
combination moving and then
manually apply the trailer brake
controller to check that the trailer
brakes work. During the trip,
occasionally check that the cargo
and trailer are secure and that the
lamps and any trailer brakes are
working.
Towing with a Stability Control
System
When towing, the stability control
system might be heard. The system
reacts to vehicle movement caused by the trailer, which mainly occurs
during cornering. This is normal
when towing heavier trailers.
Following Distance
Stay at least twice as far behind the
vehicle ahead as you would when
driving without a trailer. This can
help to avoid heavy braking and
sudden turns.
Passing
More passing distance is needed
when towing a trailer. The
combination of the vehicle and
trailer will not accelerate as quickly
and is much longer than the vehicle
alone. It is necessary to go much
farther beyond the passed vehicle
before returning to the lane. Pass
on level roadways. Avoid passing
on hills if possible.
Backing Up
Hold the bottom of the steering
wheel with one hand. To move the
trailer to the left, move that hand to
the left. To move the trailer to the
right, move that hand to the right.
Always back up slowly and,
if possible, have someone
guide you.
Making Turns
Caution
Turn more slowly and make wider
arcs when towing a trailer to
prevent damage to your vehicle.
Making very sharp turns could
cause the trailer to contact the
vehicle.
Make wider turns than normal when
towing, so trailer will not go over soft
shoulders, over curbs, or strike road
signs, trees, or other objects.
Always signal turns well in advance.
Do not steer or brake suddenly.
Driving on Grades
Reduce speed and shift to a lower
gear before starting down a long or
steep downhill grade. If the
transmission is not shifted down, the
brakes may overheat and result in
reduced braking efficiency.

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/5/19
Vehicle Care 277
3. Lift the hood and release thehood prop rod from its retainer
in the front of the engine
compartment. Securely insert
the rod end into the slot
marked with an arrow, on the
underside of the hood.
To close the hood: 1. Before closing the hood, be sure all filler caps are on
properly, and all tools are
removed. 2. Lift the hood and remove the
hood prop rod from the
underside of the hood. Return
the prop rod to its retainer. The
prop rod must click into place
when returning it to the retainer
to prevent hood damage.
3. Lower the hood 20 cm (8 in) above the vehicle and release
it. Check to make sure the
hood is latched completely.
Repeat this process with
additional force 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.

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/5/19
294 Vehicle Care
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 withthe proper 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 fans. 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.
6. Verify coolant level after the engine is shut 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.
Engine Overheating
The vehicle has an engine coolant
temperature gauge on the
instrument cluster and overheat
messages in the Driver Information
Center (DIC) to warn of engine
overheating. See Engine Coolant
Temperature Gauge 0112.
The decision may be made not to lift
the hood when the engine coolant
temperature gauge is in the
overheat zone or an engine
overheat DIC message displays, but
instead to get service help right
away. See Roadside Assistance
Program 0389.
If the decision to lift the hood is
made, make sure the vehicle is
parked on a level surface. Then
check to see if the engine cooling
fan(s) are running. If the engine is
overheating, the fan(s) should be
running. If they are not, do not
continue to run the engine, and
have the vehicle serviced.

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/5/19
Vehicle Care 301
2. Lift up on the latch in themiddle of the wiper blade
where the wiper arm attaches.
3. With the latch open, pull the wiper blade down toward the
windshield far enough to
release it from the J-hooked
end of the wiper arm.
4. Remove the wiper blade.
5. Reverse Steps 1–3 for wiper blade replacement.
Rear Wiper Blade Replacement
The rear wiper blade and wiper arm
have a cover for protection.
To remove the cover:
1. Slide a plastic tool under thecover and push upward to
unsnap.
2. Slide the cover toward the wiper blade tip to unhook it
from the blade assembly.
3. Remove the cover.
4. After wiper blade replacement, ensure that the cover hook
slides into the slot in the blade
assembly.
5. Snap the cover down to secure. To replace the wiper blade:
1. Lift the wiper arm away from the windshield.
2. Push the release lever (2) todisengage the hook and push
the wiper arm (1) out of the
blade assembly (3).
3. Push the new blade assembly securely on the wiper arm until
the release lever clicks into
place.
Windshield Replacement
Driver Assistance Systems
If the windshield needs to be
replaced and the vehicle is
equipped with a front camera sensor
for the Driver Assistance Systems, a