Page 244 of 408

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-10664916) - 2018 - crc - 9/15/17
Driving and Operating 243
freezing that may affect vehicle
starting. You may need to turn the
ignition on and off a few times
before the vehicle will start. Also,
idle the vehicle for a couple of
minutes before accelerating.
Water in Fuel (Diesel)
Improper fuel tank inspection or
cleaning, or contaminated fuel from
suppliers, can cause water to be
pumped into the fuel tank along with
the diesel fuel. If a WATER IN FUEL
- CONTACT SERVICE message
displays, the water must be drained
immediately.
{Warning
Diesel fuel containing water is still
combustible. You or others could
be burned. If the fuel needs to be
drained, keep sparks, flames, and
smoking materials away from the
mixture.
Caution
Water in the diesel fuel can
corrode internal components of
the fuel system and lead to
severe damage. It can also
support fungus or bacteria
growth, which can damage the
fuel system and fuel operated
heater (FOH) (if equipped). Even
with a diesel fuel biocide, the fuel
system may still need to be
cleaned. Your dealer can advise
of the appropriate solution.
If the fuel tank needs to be
purged to remove water, see your
dealer or a qualified technician.
Improper purging can damage the
fuel system and block the FOH.
As an added precaution, drain the
diesel fuel filter of residual water at
every engine oil change. If the
WATER IN FUEL - CONTACT
SERVICE message comes on
frequently, even after draining water
from the fuel filter, see your dealer. Water in Fuel Troubleshooting
If the WATER IN FUEL - CONTACT
SERVICE message comes on:
Problem Recommended
Action
Message
displays but
goes off during
the ignition
cycle. The fuel filter is
partially filled
with water. Drain
the water as
soon as
possible. See
"Removing
Water from the
Fuel Filter"
following.
Page 245 of 408

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-10664916) - 2018 - crc - 9/15/17
244 Driving and Operating
ProblemRecommended
Action
Message
displays and
stays on. Drain the fuel
filter
immediately.
If no water can
be drained, and
the temperature
is below
freezing, then
water may be
frozen in the
filter. Move the
vehicle to a
warm location to
thaw the water,
then drain the
fuel. If water still
does not drain,
see your dealer. Problem
Recommended
Action
Immediately
after refueling,
message
displays and
stays on. A large amount
of water is in the
fuel tank. Drain
the fuel filter
immediately.
If the message
stays on or
comes back on
without
refueling, then
fuel tank purging
is required. See
your dealer.
If the message
displays and the
engine stalls or
runs rough, do
not drive until
the water
contaminated
fuel is drained.Caution
Driving with this message on can
damage the fuel injection system
and the engine. If the message
comes on right after a refuel,
water was pumped into the fuel
tank. Turn off the engine and
drain the water immediately.
Removing Water from the Fuel
Filter
To drain water: 1. Turn the engine off and apply the parking brake.
2. Place a container under the filter drain valve, which is on
the bottom of the fuel filter.
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GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-10664916) - 2018 - crc - 9/15/17
250 Driving and Operating
Caution (Continued)
of fuel cap may not fit properly,
may cause the malfunction
indicator lamp to light, and could
damage the fuel tank and
emissions system. See
Malfunction Indicator Lamp
(Check Engine Light)0127.
Diesel fuel can foam when filling the
tank. This can cause the automatic
pump nozzle to shut off, even if the
tank is not full. If this happens, wait
for the foaming to stop, and then fill
the tank more slowly.
{Warning
Heat coming from the engine can
cause the fuel to expand and
force the fuel out of the tank.
If something ignites the fuel, a fire
could start. To help avoid this, fill
the tank slowly and only until the
nozzle shuts off. Do not top it off.
Clean up any spilled fuel. Accidental Refueling with
Gasoline
If the vehicle is accidentally refueled
with gasoline, do not continue
driving the vehicle except to get to a
location where it can be stopped
safely. Driving the vehicle will
damage the fuel system. Have the
vehicle towed to a qualified
technician to have the gasoline
removed from the tank and fuel
system. Flush the fuel system with
Ultra Low Sulfur Diesel fuel to
ensure all gasoline is removed.
Diesel Exhaust Fluid (DEF)
DEF is a non-toxic solution that is
sprayed into the exhaust stream of
diesel vehicles to cause a chemical
reaction and break down NOx
emissions into harmless nitrogen
and water.
DEF is not a fuel additive and never
comes into contact with diesel fuel.
It is stored in a separate tank. The
fill port is behind the fuel door next
to the regular fuel cap. It has a blue
filler cap. See
Diesel Exhaust Fluid
0 198.
Filling a Portable Fuel
Container
{Warning
Filling a portable fuel container
while it is in the vehicle can cause
fuel vapors that can ignite either
by static electricity or other
means. You or others could be
badly burned and the vehicle
could be damaged. Always:
(Continued)
Page 278 of 408

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-10664916) - 2018 - crc - 9/15/17
Vehicle Care 277
2.0L Gas Engine
1. Engine Cooling Fans (Outof View)
2. Engine Coolant Surge Tank and Pressure Cap
{Warning
An underhood electric fan 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.
{Warning
Do not touch heater or radiator
hoses, or other engine parts.
They can be very hot and can
burn you. Do not run the engine if
there is a leak; all coolant could
leak out. That could cause an
engine fire and can burn you. Fix
any leak before driving the
vehicle.
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
top rib on the middle of the tank. 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.
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.
Engine Coolant
The engine cooling system in the
vehicle is filled with DEX-COOL
engine coolant mixture. This coolant
needs to be checked and changed
at appropriate levels.
See
Recommended Fluids and
Lubricants 0361 andMaintenance
Schedule 0353.
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 0280.
What to Use
{Warning
Plain water, or other liquids such
as alcohol, can boil before the
proper coolant mixture will. With
plain water or the wrong mixture,
the engine could get too hot but
(Continued)