service GMC TERRAIN 2012 Repair Manual

Black plate (13,1)GMC Terrain Owner Manual (Include Mex) - 2012
Vehicle Care 10-13
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. Turn the ignition to ON/RUN,with the engine off.
2. Press the DIC MENU button to display the Vehicle
Information menu.
3. Press either the up or down arrows to view REMAINING
OIL LIFE.
4. Press the SET/CLR button until 100% is displayed.
5. Turn the key to LOCK/OFF.
Or:
1. Turn the ignition to ON/RUN with the engine off.
2. Fully press and release the accelerator pedal three times
within five seconds. The system is reset when the
CHANGE ENGINE OIL SOON
message goes off.
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.

Black plate (14,1)GMC Terrain Owner Manual (Include Mex) - 2012
10-14 Vehicle Care
There is a special procedure for
checking and changing the
transmission fluid. Because this
procedure is difficult, this should be
done at your dealer. Contact your
dealer for additional information or
the procedure can be found in the
service manual. To purchase a
service manual, seeService
Publications Ordering Information
on page 13‑17.
Change the fluid and filter at the
intervals listed in Maintenance
Schedule on page 11‑3, and be sure
to use the fluid listed in
Recommended Fluids and
Lubricants on page 11‑12.Engine Air Cleaner/Filter
See Engine Compartment Overview
on page 10‑6 for the location of the
engine air cleaner/filter.
When to Inspect the Engine Air
Cleaner/Filter
Inspect or replace the air cleaner/
filter at the scheduled maintenance
intervals. See Maintenance
Schedule on page 11‑3 for more
information. If driving in dusty/dirty
conditions, inspect the filter at each
engine oil change.
How to Inspect the Engine Air
Cleaner/Filter
To inspect the air cleaner/filter,
remove the filter from the vehicle
and lightly shake the filter to release
loose dust and dirt. If the filter
remains covered with dirt, a new
filter is required. Never use
compressed air to clean the filter. To inspect or replace the engine air
cleaner/filter:
1. Open the hood. See
Hood on
page 10‑5.
2. Locate the air filter housing on the passenger side of the engine
compartment. See Engine
Compartment Overview on
page 10‑6.
3. Remove the four air cleaner housing cover screws.

Black plate (16,1)GMC Terrain Owner Manual (Include Mex) - 2012
10-16 Vehicle Care
3.0L V6 Engine
A. Engine Cooling Fans (Out of View)
B. Engine Coolant Surge Tank and Pressure Cap
{WARNING
An electric engine cooling fan
under the hood can start up even
when the engine is not running
and can cause injury. Keep
hands, clothing, and tools away
from any underhood electric fan. If the coolant inside the coolant
surge tank is boiling, do not do
anything else until it cools down.
The vehicle should be parked on a
level surface.
The coolant level should be at the
COLD FILL line. If it is not, the
vehicle may have a leak at the
radiator hoses, heater hoses,
radiator, water pump, or somewhere
else in the cooling system.
{WARNING
Heater and radiator hoses, and
other engine parts, can be very
hot. Do not touch them. If you do,
you can be burned.
Do not run the engine if there is a
leak. If you run the engine, it
could lose all coolant. That could
cause an engine fire, and you
could be burned. Get any leak
fixed before you drive the vehicle.
If there seems to be no leak, with
the engine on, check to see if the
electric engine cooling fan is
running. If the engine is
overheating, the fan should be
running. If it is not, the vehicle
needs service. Turn off the engine.
Notice:
Using coolant other than
DEX-COOL
®can cause premature
engine, heater core, or radiator
corrosion. In addition, the engine
coolant could require changing
sooner, at 50 000 km (30,000 mi)
or 24 months, whichever occurs
first. Any repairs would not be
covered by the vehicle warranty.
Always use DEX-COOL
(silicate-free) coolant in the
vehicle.

Black plate (17,1)GMC Terrain Owner Manual (Include Mex) - 2012
Vehicle Care 10-17
Engine Coolant
The cooling system in the vehicle is
filled with DEX-COOL®engine
coolant. This coolant is designed to
remain in the vehicle for 5 years or
240 000 km (150,000 mi), whichever
occurs first.
The following explains the cooling
system and how to check and add
coolant when it is low. If there is a
problem with engine overheating,
see Engine Overheating on
page 10‑20.
What to Use
{WARNING
Adding only plain water or some
other liquid to the cooling system
can be dangerous. Plain water
and other liquids, can boil before
the proper coolant mixture will.
The coolant warning system is set
for the proper coolant mixture.
(Continued)
WARNING (Continued)
With plain water or the wrong
mixture, the engine could get too
hot but you would not get the
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.
Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
coolant. If using this mixture,
nothing else needs to be added.
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.
Notice: If an improper coolant
mixture is used, the engine could
overheat and be badly damaged.
The repair cost would not be
covered by the vehicle warranty.
Too much water in the mixture
can freeze and crack the engine,
radiator, heater core, and other
parts.
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.

Black plate (20,1)GMC Terrain Owner Manual (Include Mex) - 2012
10-20 Vehicle Care
3. Fill the coolant surge tank withthe proper DEX-COOL coolant
mixture, to the COLD FILL line.
4. With the coolant surge tank pressure cap off, start the
engine and let it run until the
upper radiator hose can be felt
getting hot. Watch out for the
engine cooling fan(s).
By this time, the coolant level
inside the coolant surge tank
may be lower. If the level is
lower, add more of the proper
DEX-COOL coolant mixture to the coolant surge tank until the
level reaches the COLD
FILL line.
5. Replace the pressure cap. Be sure the pressure cap is
hand-tight.
Check the level in the coolant surge
tank when the cooling system has
cooled down. If the coolant is not at
the proper level, repeat Steps 1
through 3 and reinstall the pressure
cap. If the coolant still is not at the
proper level when the system cools
down again, see your dealer.
Engine Overheating
The vehicle has an indicator to warn
of engine overheating. There is an
engine coolant temperature warning
light on the vehicle's instrument
panel. See Engine Coolant
Temperature Gauge on page 5‑10. The decision may be made not to lift
the hood when this warning
appears, but instead get service
help right away. See
Roadside
Assistance Program (U.S. and
Canada) on page 13‑7 orRoadside
Assistance Program (Mexico) on
page 13‑9.
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.
Notice: Engine damage from
running the engine without
coolant is not covered by the
warranty.

Black plate (23,1)GMC Terrain Owner Manual (Include Mex) - 2012
Vehicle Care 10-23
Washer Fluid
What to Use
Read the manufacturer's
instructions before refilling the
windshield washer fluid. If operating
the vehicle in an area where the
temperature may fall below freezing,
use a fluid that has sufficient
protection against freezing.
Adding Washer Fluid
Open the cap with the washer
symbol on it and add washer fluid
until full. SeeEngine Compartment
Overview on page 10‑6 for reservoir
location. Notice
.When using concentrated
washer fluid, follow the
manufacturer's instructions
for adding water.
.Do not mix water with
ready-to-use washer fluid.
Water can cause the solution
to freeze and damage the
washer fluid tank and other
parts of the washer system.
Also, water does not clean as
well as washer fluid.
.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.
.Do not use engine coolant
(antifreeze) in the windshield
washer. It can damage the
windshield washer system
and paint.
Brakes
This vehicle has disc 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 be
heard all the time 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.
Notice: Continuing to drive with
worn-out brake pads could result
in costly brake repair.

Black plate (24,1)GMC Terrain Owner Manual (Include Mex) - 2012
10-24 Vehicle Care
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 inCapacities and
Specifications on page 12‑2.
Brake linings should always be
replaced as complete axle 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 might be
required.
Brake Adjustment
Every time the brakes are applied,
with or without the vehicle moving,
the brakes adjust for wear.
Replacing Brake System Parts
The braking system on a vehicle is
complex. Its many parts have to be
of top quality and work well together
if the vehicle is to have really good
braking. The vehicle was designed
and tested with top-quality brake
parts. When parts of the braking
system are replaced, be sure to get
new, approved replacement parts.
If this is not done, the brakes might
not work properly. For example,
installing disc brake pads that are
wrong for the vehicle, can change
the balance between the front and
rear brakes —for the worse. The
braking performance expected can
change in many other ways if the
wrong replacement brake parts are
installed.
Brake Fluid
The brake master cylinder reservoir
is filled with DOT 3 brake fluid as
indicated on the reservoir cap. See
Engine Compartment Overview on
page 10‑6 for the location of the
reservoir.
There are only two reasons why the
brake fluid level in the reservoir
might go down:
.The brake fluid level goes down
because of normal brake lining
wear. When new linings are
installed, the fluid level goes
back up.

Black plate (27,1)GMC Terrain Owner Manual (Include Mex) - 2012
Vehicle Care 10-27
What to Use
Refer toRecommended Fluids and
Lubricants on page 11‑12 to
determine what kind of lubricant
to use.
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. Firmly apply both the parking
brake and the regular brake.
See Parking Brake on
page 9‑33.
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. Firmly apply the parking brake. See Parking Brake on
page 9‑33.
Be ready to apply the regular
brake immediately if the vehicle
begins to move.

Black plate (28,1)GMC Terrain Owner Manual (Include Mex) - 2012
10-28 Vehicle Care
3. With the engine off, turn theignition 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.
Ignition Transmission
Lock Check
While parked, and with the parking
brake set, try to turn the ignition to
LOCK/OFF in each shift lever
position.
.The ignition should turn to
LOCK/OFF only when the shift
lever is in P (Park).
.The ignition key should come
out only in LOCK/OFF.
Contact your dealer if service is
required.
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
inspected for wear and cracking.
See Maintenance Schedule on
page 11‑3 for more information.
Replacement blades come in
different types and are removed in
different ways. For proper type and
length, see Maintenance
Replacement Parts on page 11‑14.
Notice: 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 your warranty. Do not
allow the wiper arm to touch the
windshield.

Black plate (44,1)GMC Terrain Owner Manual (Include Mex) - 2012
10-44 Vehicle Care
Mini Fuses Usage35 Sensing and
Diagnostic Module
Battery
36 Data Link
Connection
37 Instrument Panel
Cluster Battery
38 Passenger Sensing
System Module
39 Spare
J‐Case Fuses Usage
29 Front Blower Motor
40 Body Control
Module 8
Relays Usage 41 Logistic Relay (If
Equipped)
42 Retained Accessory
Power RelayWheels and Tires
Tires
Every new GM vehicle has
high-quality tires made by a
leading tire manufacturer. See
the warranty manual for
information regarding the tire
warranty and where to get
service. For additional
information refer to the tire
manufacturer.
{WARNING
.Poorly maintained and
improperly used tires are
dangerous.
.Overloading the tires can
cause overheating as a result
of too much flexing. There
could be a blowout and a
serious crash. See
Vehicle
Load Limits on page 9‑16.
.Underinflated tires pose the
same danger as overloaded
tires. The resulting crash
could cause serious injury.
Check all tires frequently to
maintain the recommended
pressure. Tire pressure
should be checked when the
tires are cold.
(Continued)