engine GMC SAVANA 2013 Repair Manual

Black plate (29,1)GMC Savana Owner Manual - 2013 - 2nd Edition - 9/25/12
Driving and Operating 9-29
Tow/Haul Mode
Vehicles with an automatic
transmission have a Tow/Haul
Mode. The Tow/Haul Mode adjusts
the transmission shift pattern to
reduce shift cycling, providing
increased performance, vehicle
control, and transmission cooling
when towing or hauling heavy loads.
Turn the Tow/Haul Mode on and off
by pressing the button on the
instrument panel. When Tow/Haul is
on, a light on the instrument cluster
will come on.See
Tow/Haul Mode Light on
page 5‑21 for more information.
Also see “Tow/Haul Mode” under
Towing Equipment on page 9‑54.
Tow/Haul Mode Grade Braking
(6-Speed Automatic
Transmission)
Tow/Haul Mode Grade Braking is
only enabled while the Tow/Haul
Mode is selected and the vehicle is
not in the Range Selection Mode.
See “Tow/Haul Mode” listed
previously and Manual Mode on
page 9‑28. Tow/Haul Mode Grade
Braking assists in maintaining
desired vehicle speeds when driving
on downhill grades by using the
engine and transmission to slow the
vehicle.
To disable or enable Tow/Haul
Grade Braking within the current
ignition key cycle, press and hold
the Tow/Haul button for
three seconds. A DIC message will
be displayed. See Transmission
Messages on page 5‑37. See
Towing Equipment on
page 9‑54.
For other forms of grade braking,
see Automatic Transmission (Six
Speed) on page 9‑22 orAutomatic
Transmission (Four Speed) on
page 9‑26 andCruise Control on
page 9‑34.

Black plate (30,1)GMC Savana Owner Manual - 2013 - 2nd Edition - 9/25/12
9-30 Driving and Operating
Drive Systems
All-Wheel Drive
If the vehicle has this feature,
engine power is sent to all four
wheels when extra traction is
needed. This is like four-wheel
drive, but there is no separate lever
or switch to engage or disengage
the front axle. It is fully automatic,
and adjusts itself as needed for road
conditions.
Brakes
Antilock Brake
System (ABS)
This vehicle has the Antilock Brake
System (ABS), an advanced
electronic braking system that helps
prevent a braking skid.
When the engine is started and the
vehicle begins to drive away, ABS
checks itself. A momentary motor or
clicking noise might be heard while
this test is going on, and it might
even be noticed that the brake
pedal moves a little. This is normal.
If there is a problem with ABS, this
warning light stays on. SeeAntilock
Brake System (ABS) Warning Light
on page 5‑21. If driving safely on a wet road and it
becomes necessary to slam on the
brakes and continue braking to
avoid a sudden obstacle, a
computer senses that the wheels
are slowing down. If one of the
wheels is about to stop rolling, the
computer will separately work the
brakes at each wheel.
ABS can change the brake pressure
to each wheel, as required, faster
than any driver could. This can help
the driver steer around the obstacle
while braking hard.
As the brakes are applied, the
computer keeps receiving updates
on wheel speed and controls
braking pressure accordingly.
Remember: ABS does not change
the time needed to get a foot up to
the brake pedal or always decrease
stopping distance. If you get too
close to the vehicle in front of you,
there will not be enough time to
apply the brakes if that vehicle

Black plate (33,1)GMC Savana Owner Manual - 2013 - 2nd Edition - 9/25/12
Driving and Operating 9-33
illuminates and the appropriate
messages will be displayed in
the DIC.
To turn StabiliTrak and TCS back
on, press the StabiliTrak button
again. StabiliTrak will automatically
turn back on when the vehicle
speed exceeds 40 km/h (25 mph).
When the StabiliTrak system has
been turned off, system noises may
still be heard as a result of the
brake-traction control coming on.
It is recommended to leave the
system on for normal driving
conditions, but it may be necessary
to turn the system off if the vehicle
is stuck in sand, mud, ice or snow,
and you want to“rock”the vehicle to
attempt to free it. See If the Vehicle
Is Stuck on page 9‑9.
StabiliTrak System Operation
The StabiliTrak system is normally
on, except when the system is
initializing or has been disabled with
the StabiliTrak button. The
StabiliTrak system will automatically activate to assist the driver in
maintaining vehicle directional
control in most driving conditions.
When activated, the StabiliTrak
system may reduce engine power to
the wheels and apply braking to
individual wheels as necessary to
assist the driver with vehicle
directional control. If cruise control
is being used when StabiliTrak
activates, the cruise control
automatically disengages. The
cruise control can be re-engaged
when road conditions allow. See
Cruise Control on page 9‑34.
The StabiliTrak system may also
turn off automatically if it determines
that a problem exists with the
system. If the problem does not
clear itself after restarting the
vehicle, see your dealer for service.
Traction Control Operation
TCS is part of the StabiliTrak
system. TCS limits wheel spin by
reducing engine power to the
wheels and by applying brakes to
each individual wheel as necessary.If the brake-traction control system
activates constantly or if the brakes
have heated up due to high speed
braking, the brake-traction control
will be automatically disabled. The
system will come back on after the
brakes have cooled. This can take
up to two minutes or longer
depending on brake usage.
TCS may activate on dry or rough
roads or under conditions such as
heavy acceleration while turning or
abrupt upshifts/downshifts of the
transmission. When this reduction in
acceleration occurs, it may be
noticed, or a noise or vibration may
be heard. This is normal.
Adding non-dealer accessories can
affect the vehicle's performance.
See
Accessories and Modifications
on page 10‑3 for more information.

Black plate (36,1)GMC Savana Owner Manual - 2013 - 2nd Edition - 9/25/12
9-36 Driving and Operating
Using Cruise Control on Hills
How well the cruise control works
on hills depends on the vehicle
speed, the load, and the steepness
of the hills. When going up steep
hills, pressing the accelerator pedal
may be necessary to maintain
vehicle speed.
While going downhill:
.Vehicles with a four speed
automatic transmission may
need to have the brakes applied
or the transmission shifted to a
lower gear to help maintain
driver selected speed.
.Vehicles with a six speed
automatic transmission have
Cruise Grade Braking to help
maintain driver selected speed.
Cruise Grade Braking is enabled
when the vehicle is started and
Cruise Control is active. It is not
enabled in Range Selection Mode.
It assists in maintaining driver
selected speed when driving on downhill grades by using the engine
and transmission to slow the
vehicle.
To disable and enable Cruise Grade
Braking for the current ignition key
cycle, press and hold the Tow/Haul
button for three seconds. A DIC
message displays. See
Transmission Messages on
page 5‑37.
When the brakes are manually
applied the cruise control is
disengaged.
Ending Cruise Control
There are three ways to end cruise
control:
.To disengage cruise control,
step lightly on the brake pedal.
.Press the[on the steering
wheel.
.To turn off the cruise control,
press
Ion the steering wheel. Erasing Speed Memory
The cruise control set speed is
erased from memory if
Iis
pressed or if the vehicle is
turned off.

Black plate (41,1)GMC Savana Owner Manual - 2013 - 2nd Edition - 9/25/12
Driving and Operating 9-41
can change or the camera can
be affected. Be sure to have the
camera and its position and
mounting angle checked at your
dealer.
The RVC system display in the
rearview mirror may turn off or not
appear as expected due to one of
the following conditions. If this
occurs the left indicator light on the
mirror will flash.
.A slow flash may indicate a loss
of video signal, or no video
signal present during the reverse
cycle.
.A fast flash may indicate that the
display has been on for the
maximum allowable time during
a reverse cycle, or the display
has reached an Over
Temperature limit.
The fast flash conditions are
used to protect the video device
from high temperature
conditions. Once conditions return to normal the device will
reset and the green indicator will
stop flashing.
During any of these fault conditions,
the display will be blank and the
indicator will flash while the vehicle
is in R (Reverse) or until the
conditions return to normal.
Fuel
For diesel engine vehicles, see
“Fuel for Diesel Engines” in the
Duramax diesel supplement.
For Vehicles with gasoline engines,
please read this.
Gasoline
Use of the recommended fuel is an
important part of the proper
maintenance of this vehicle. To help
keep the engine clean and maintain
optimum vehicle performance, we
recommend the use of gasoline
advertised as TOP TIER Detergent
Gasoline.
Look for the TOP TIER label on the
fuel pump to ensure gasoline meets
enhanced detergency standards
developed by auto companies. A list
of marketers providing TOP TIER
Detergent Gasoline can be found at
www.toptiergas.com. TOP TIER
gasoline is only available in the U.S.
and Canada.

Black plate (42,1)GMC Savana Owner Manual - 2013 - 2nd Edition - 9/25/12
9-42 Driving and Operating
Vehicles that have a yellow fuel cap
can use either unleaded gasoline or
ethanol fuel containing up to 85%
ethanol (E85). SeeFuel E85 (85%
Ethanol) on page 9‑44. For all other
vehicles, use only the unleaded
gasoline described under
Recommended Fuel on page 9‑42.
Recommended Fuel
Use regular unleaded gasoline with
a posted octane rating of 87 or
higher. If the octane rating is less
than 87, an audible knocking noise,
commonly referred to as spark
knock, might be heard when driving. If this occurs, use a gasoline rated
at 87 octane or higher as soon as
possible. If heavy knocking is heard
when using gasoline rated at
87 octane or higher, the engine
needs service.
Gasolines containing oxygenates,
such as ethers and ethanol, as well
as reformulated gasolines are
available in some cities. If these
gasolines comply with the
previousely described specification,
then they are acceptable to use.
However, E85 (85% ethanol) and
other fuels containing more than
15% ethanol must be used only in
flex fuel vehicles.
{CAUTION
Do not use fuel containing
methanol. It can corrode metal
parts in the fuel system and also
damage plastic and rubber parts.
That damage would not be
covered under the vehicle
warranty.
Some gasolines that are not
reformulated for low emissions can
contain an octane-enhancing
additive called
methylcyclopentadienyl manganese
tricarbonyl (MMT). Do not use
gasolines with MMT as they can
reduce spark plug life and affect
emission control system
performance. The malfunction
indicator lamp may turn on. If this
occurs, see your dealer for service.
Gasoline Specifications
At a minimum, gasoline should meet
ASTM specification D 4814. Some
gasolines contain an
octane-enhancing additive called
methylcyclopentadienyl manganese
tricarbonyl (MMT). We recommend
against the use of gasolines
containing MMT. See
Fuel Additives
on page 9‑43.

Black plate (43,1)GMC Savana Owner Manual - 2013 - 2nd Edition - 9/25/12
Driving and Operating 9-43
California Fuel
Requirements
If the vehicle is certified to meet
California Emissions Standards, it is
designed to operate on fuels that
meet California specifications. See
the underhood emission control
label. If this fuel is not available in
states adopting California Emissions
Standards, the vehicle will operate
satisfactorily on fuels meeting
federal specifications, but emission
control system performance might
be affected. The malfunction
indicator lamp could turn on and the
vehicle might fail a smog‐check test.
SeeMalfunction Indicator Lamp on
page 5‑17. If this occurs, return to
your authorized dealer for diagnosis.
If it is determined that the condition
is caused by the type of fuel used,
repairs might not be covered by the
vehicle warranty.
Fuels in Foreign
Countries
If planning to drive in countries
outside the U.S. or Canada, the
proper fuel might be hard to find.
Check regional auto club or fuel
retail brand websites for availability
in the country where driving. Never
use leaded gasoline, fuel containing
methanol, or any other fuel not
recommended. Costly repairs
caused by use of improper fuel
would not be covered by the vehicle
warranty.
Fuel Additives
To provide cleaner air, all gasolines
in the United States are now
required to contain additives that
help prevent engine and fuel system
deposits from forming, allowing the
emission control system to work
properly. In most cases, nothing
should have to be added to the fuel.
However, some gasolines contain
only the minimum amount of
additive required to meet U.S. Environmental Protection Agency
regulations. To help keep fuel
injectors and intake valves clean
and avoid problems due to dirty
injectors or valves, look for gasoline
that is advertised as TOP TIER
Detergent Gasoline. Look for the
TOP TIER label on the fuel pump to
ensure gasoline meets enhanced
detergency standards developed by
the auto companies. A list of
marketers providing TOP TIER
Detergent Gasoline can be found at
www.toptiergas.com.
For customers who do not use TOP
TIER Detergent Gasoline regularly,
one bottle of GM Fuel System
Treatment PLUS, added to the fuel
tank at every engine oil change, can
help clean deposits from fuel
injectors and intake valves. GM Fuel
System Treatment PLUS is the only
gasoline additive recommended by
General Motors. It is available at
your dealer.
Gasolines containing oxygenates,
such as ethers and ethanol, and
reformulated gasolines might be

Black plate (45,1)GMC Savana Owner Manual - 2013 - 2nd Edition - 9/25/12
Driving and Operating 9-45
E85 has less energy per liter
(gallon) than gasoline, so you will
need to refill the fuel tank more
often when using E85 than when
you are using gasoline. SeeFilling
the Tank on page 9‑45.
Notice: Some additives are not
compatible with E85 fuel and can
harm the vehicle's fuel system.
Do not add anything to E85.
Damage caused by additives
would not be covered by the
vehicle warranty.
Notice: This vehicle was not
designed for fuel that contains
methanol. Do not use fuel
containing methanol. It can
corrode metal parts in the fuel
system and also damage plastic
and rubber parts. That damage
would not be covered under the
vehicle warranty.Filling the Tank
{WARNING
Fuel vapors and fuel fires burn
violently and can cause injury or
death.
.To help avoid injuries to you
and others, read and follow
all the instructions on the fuel
pump island.
.Turn off the engine when
refueling.
.Keep sparks, flames, and
smoking materials away
from fuel.
.Do not leave the fuel pump
unattended.
.Do not reenter the vehicle
while pumping fuel.
.Keep children away from the
fuel pump and never let
children pump fuel.
(Continued)
WARNING (Continued)
.Fuel can spray out if the fuel
cap is opened too quickly.
This spray can happen if the
tank is nearly full, and is
more likely in hot weather.
Open the fuel cap slowly and
wait for any hiss noise to stop
then unscrew the cap all
the way
The tethered fuel cap is located
behind a hinged fuel door on the
driver side of the vehicle.
If the vehicle has E85 fuel capability,
the fuel cap will be yellow and state
that E85 or gasoline can be used.
See Fuel E85 (85% Ethanol) on
page 9‑44.
To remove the fuel cap, turn it
slowly counterclockwise.
While refueling, hang the tethered
fuel cap from the hook on the
fuel door.

Black plate (47,1)GMC Savana Owner Manual - 2013 - 2nd Edition - 9/25/12
Driving and Operating 9-47
Towing
General Towing
Information
Only use towing equipment that has
been designed for the vehicle.
Contact your dealer or trailering
dealer for assistance with preparing
the vehicle for towing a trailer. Read
the entire section before towing a
trailer.
For towing a disabled vehicle, see
Towing the Vehicle on page 10‑80.
For towing the vehicle behind
another vehicle such as a motor
home, seeRecreational Vehicle
Towing on page 10‑80.
Driving Characteristics
and Towing Tips
Driving with a Trailer
When towing a trailer:
.Become familiar with the state
and local laws that apply to
trailer towing.
.Do not tow a trailer during the
first 800 km (500 mi) to prevent
damage to the engine, axle,
or other parts.
.Then during the first 800 km
(500 mi) of trailer towing, do not
drive over 80 km/h (50 mph) and
do not make starts at full throttle.
.Vehicles can tow in D (Drive).
Shift the transmission to a lower
gear if the transmission shifts
too often under heavy loads and/
or hilly conditions.
{WARNING
When towing a trailer, exhaust
gases may collect at the rear of
the vehicle and enter if the
liftgate, trunk/hatch, or rear-most
window is open.
When towing a trailer:
.Do not drive with the liftgate,
trunk/hatch, or rear-most
window open.
(Continued)
WARNING (Continued)
.Fully open the air outlets on
or under the instrument
panel.
.Also adjust the climate
control system to a setting
that brings in only outside air.
See“Climate Control System”
in the Index.
For more information about
Carbon Monoxide, see Engine
Exhaust on page 9‑21.
Towing a trailer requires a certain
amount of experience. The
combination you are driving is
longer and not as responsive as the
vehicle itself. Get acquainted with
the handling and braking of the rig
before setting out for the open road.
Before starting, check all trailer hitch
parts and attachments, safety
chains, electrical connectors, lamps,
tires, and mirrors. If the trailer has
electric brakes, start the

Black plate (48,1)GMC Savana Owner Manual - 2013 - 2nd Edition - 9/25/12
9-48 Driving and Operating
combination moving and then apply
the trailer brake controller by hand
to be sure the brakes work.
During the trip, check occasionally
to be sure that the load is secure
and the lamps and any trailer
brakes still work.
Following Distance
Stay at least twice as far behind the
vehicle ahead as you would when
driving the vehicle 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 will not accelerate as
quickly and is longer so it is
necessary to go much farther
beyond the passed vehicle before
returning to the lane.
Backing Up
Hold the bottom of the steering
wheel with one hand. To move the
trailer to the left, move that hand tothe left. To move the trailer to the
right, move your hand to the right.
Always back up slowly and,
if possible, have someone
guide you.
Making Turns
Notice:
Making very sharp turns
while trailering could cause the
trailer to come in contact with the
vehicle. The vehicle could be
damaged. Avoid making very
sharp turns while trailering.
When turning with a trailer, make
wider turns than normal. Do this so
the trailer will not strike soft
shoulders, curbs, road signs, trees,
or other objects. Avoid jerky or
sudden maneuvers. Signal well in
advance.
If the trailer turn signal bulbs burn
out, the arrows on the instrument
cluster will still flash for turns. It is
important to check occasionally to
be sure the trailer bulbs are still
working.
Driving on Grades
Reduce speed and shift to a lower
gear before starting down a long or
steep downgrade. If the
transmission is not shifted down, the
brakes might get hot and no longer
work well.
Vehicles can tow in D (Drive). Shift
the transmission to a lower gear if
the transmission shifts too often
under heavy loads and/or hilly
conditions.
The Tow/Haul Mode may be used if
the transmission shifts too often.
See Tow/Haul Mode on page 9‑29.
When towing at high altitude on
steep uphill grades, consider the
following: Engine coolant will boil at
a lower temperature than at normal
altitudes. If the engine is turned off
immediately after towing at high
altitude on steep uphill grades, the
vehicle may show signs similar to
engine overheating. To avoid this,
let the engine run while parked,
preferably on level ground, with the
automatic transmission in P (Park)