2015 GMC SAVANA engine

Black plate (22,1)GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-7707482) -
2015 - crc - 1/20/15
9-22 Driving and Operating
Warning (Continued)
.There are holes or openings
in the vehicle body from
damage or aftermarket
modifications that are not
completely sealed.
If unusual fumes are detected or
if it is suspected that exhaust is
coming into the vehicle:
.Drive it only with the windows
completely down.
.Have the vehicle repaired
immediately.
Never park the vehicle with the
engine running in an enclosed
area such as a garage or a
building that has no fresh air
ventilation.
Running the Vehicle
While Parked
It is better not to park with the
engine running.
If the vehicle is left with the engine
running, follow the proper steps to
be sure the vehicle will not move.
See Shifting Into Park on page 9-19
and Engine Exhaust on page 9-21.
If parking on a hill and pulling a
trailer, see Driving Characteristics
and Towing Tips on page 9-44.
Automatic
Transmission
A shift position indicator is in the
instrument cluster.
There are several different positions
for the shift lever.
See “Range Selection Mode” under
Manual Mode on page 9-26.
P (Park): This position locks the
rear wheels. It is the best position to
use when starting the engine
because the vehicle cannot move
easily. When parked on a hill,
especially when the vehicle has a
heavy load, you might notice an
increase in the effort to shift out of
P (Park). See “Torque Lock” under
Shifting Into Park on page 9-19.

Black plate (23,1)GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-7707482) -
2015 - crc - 1/20/15
Driving and Operating 9-23
{Warning
It is dangerous to get out of the
vehicle if the shift lever is not fully
in P (Park) with the parking brake
firmly set. The vehicle can roll.
Do not leave the vehicle when the
engine is running. 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,
always set the parking brake and
move the shift lever to P (Park).
SeeShifting Into Park on
page 9-19 andDriving
Characteristics and Towing Tips
on page 9-44.
R (Reverse): Use this gear to
back up.
{Caution
Shifting to R (Reverse) while the
vehicle is moving forward could
damage the transmission. The
repairs would not be covered by
the vehicle warranty. Shift to
R (Reverse) only after the vehicle
is stopped.
To rock the vehicle back and forth to
get out of snow, ice, or sand without
damaging the transmission, see If
the Vehicle Is Stuck on page 9-8.
N (Neutral): In this position, the
engine does not connect with the
wheels. To restart when you are
already moving, use N (Neutral)
only. Also, use N (Neutral) when the
vehicle is being towed.
{Warning
Shifting into a drive gear while the
engine is running at high speed is
dangerous. Unless your foot is
firmly on the brake pedal, the
vehicle could move very rapidly.
You could lose control and hit
people or objects. Do not shift
into a drive gear while the engine
is running at high speed.
{Caution
Shifting out of P (Park) or
N (Neutral) with the engine
running at high speed may
damage the transmission. The
repairs would not be covered by
the vehicle warranty. Be sure the
engine is not running at high
speed when shifting the vehicle.

Black plate (24,1)GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-7707482) -
2015 - crc - 1/20/15
9-24 Driving and Operating
D (Drive):This position is for
normal driving. It provides the best
fuel economy. If you need more
power for passing, and you are:
.Going less than about 55 km/h
(35 mph), push the accelerator
pedal about halfway down.
.Going about 55 km/h (35 mph) or
more, push the accelerator all
the way down.
By doing this, the vehicle shifts
down to the next gear and has
more power.
D (Drive) can be used when towing
a trailer, carrying a heavy load,
or driving on steep hills. You might
want to shift the transmission to a
lower gear selection if the
transmission shifts too often.
Downshifting the transmission in
slippery road conditions could result
in skidding. See “Skidding”under
Loss of Control on page 9-4.
The vehicle has a shift stabilization
feature that adjusts the transmission
shifting to the current driving conditions in order to reduce rapid
upshifts and downshifts. This shift
stabilization feature is designed to
determine, before making an
upshift, if the engine is able to
maintain vehicle speed by analyzing
things such as vehicle speed,
throttle position, and vehicle load.
If the shift stabilization feature
determines that a current vehicle
speed cannot be maintained, the
transmission does not upshift and
instead holds the current gear.
In some cases, this could appear to
be a delayed shift, however the
transmission is operating normally.
The transmission uses adaptive
shift controls. Adaptive shift controls
continually compare key shift
parameters to pre-programmed
ideal shifts stored in the
transmission’s computer. The
transmission constantly makes
adjustments to improve vehicle
performance according to how the
vehicle is being used, such as with
a heavy load or when the
temperature changes. During this
adaptive shift control process,
shifting might feel different as the
transmission determines the best
settings.
The shift quality of a new vehicle
may not be ideal because the
adaptive shift control process may
not have determined the best
settings for a particular shift or
condition. Shift quality will improve
with continued driving.
When temperatures are very cold,
the transmission's gear shifting
could be delayed, providing more
stable shifts until the engine warms
up. Shifts could be more noticeable
with a cold transmission. This
difference in shifting is normal.
M (Manual Mode):
This position
lets drivers select the range of gears
appropriate for current driving
conditions. If the vehicle has this
feature, see “Range Selection
Mode” underManual Mode on
page 9-26.

Black plate (25,1)GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-7707482) -
2015 - crc - 1/20/15
Driving and Operating 9-25
3 (Third):This position is also used
for normal driving. It reduces vehicle
speed more than D (Drive) without
using the brakes. You might choose
3 (Third) instead of D (Drive) when
driving on hilly, winding roads; when
towing a trailer, so there is less
shifting between gears; and when
going down a steep hill. See “Range
Selection Mode” underManual
Mode on page 9-26.
2 (Second): This position reduces
vehicle speed even more than
3 (Third) without using the brakes.
You can use 2 (Second) on hills.
It can help control vehicle speed as
you go down steep mountain roads,
but then you would also want to use
the brakes off and on. See “Range
Selection Mode” underManual
Mode on page 9-26.
If you manually select 2 (Second) in
an automatic transmission, the
transmission will start in
second gear. You can use this
feature for reducing the speed of the rear wheels when trying to start the
vehicle from a stop on slippery road
surfaces.
1 (First):
This position reduces
vehicle speed without using the
brakes. You can use it for major/
severe downgrades where the
vehicle would otherwise accelerate
due to steepness of grade. When
you shift to 1 (First) it provides the
lowest gear appropriate to current
road speed and continues to
downshift as the vehicle slows,
eventually downshifting to 1 (First)
gear. The transmission can be held
in 1 (First) gear using Range
Selection Mode or the shift lever.
See “Range Selection Mode” under
Manual Mode on page 9-26.
{Caution
Spinning the tires or holding the
vehicle in one place on a hill
using only the accelerator pedal
may damage the transmission.
(Continued)
Caution (Continued)
The repair will not be covered by
the vehicle warranty. If you are
stuck, do not spin the tires. When
stopping on a hill, use the brakes
to hold the vehicle in place.
Normal Mode Grade Braking
This mode is enabled when the
vehicle is started, but is not enabled
in Range Selection Mode. It assists
in maintaining desired vehicle
speeds when driving on downhill
grades by using the engine and
transmission to slow the vehicle.
The first time the system activates
for each ignition key cycle, a DIC
message will be displayed. See
Transmission Messages on
page 5-36.
To disable or enable Normal Mode
Grade Braking within the current
ignition key cycle, press and hold
the Tow/Haul button for

Black plate (27,1)GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-7707482) -
2015 - crc - 1/20/15
Driving and Operating 9-27
Tow/Haul Mode
If equipped, 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.
Also see “Tow/Haul Mode” under
Towing Equipment on page 9-51.
Tow/Haul Mode Grade Braking
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 9-26. 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 Mode
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 5-36.
See Towing Equipment on
page 9-51.
For other forms of grade braking,
see Automatic Transmission on
page 9-22 andCruise Control on
page 9-32.

Black plate (31,1)GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-7707482) -
2015 - crc - 1/20/15
Driving and Operating 9-31
and you want to“rock”the vehicle to
attempt to free it. See If the Vehicle
Is Stuck on page 9-8.
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 9-32.
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.Locking Rear Axle
Vehicles with a locking rear axle can
give more traction on snow, mud,
ice, sand, or gravel. It works like a
standard axle most of the time, but
when traction is low, this feature will
allow the rear wheel with the most
traction to move the vehicle.

Black plate (34,1)GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-7707482) -
2015 - crc - 1/20/15
9-34 Driving and Operating
Using Cruise Control on Hills
How well cruise control works on
hills depends on the vehicle speed,
load, and the steepness of the hills.
When going up steep hills, you
might have to step on the
accelerator pedal to maintain your
speed.
While going downhill:
.Vehicles with a 4-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 6-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 5-36.
When the brakes are manually
applied the cruise control is
disengaged.
Ending Cruise Control
There are four ways to end cruise
control:
.Step lightly on the brake pedal.
.Press[.
.Shift the transmission to
N (Neutral).
.To turn off cruise control,
press
I.
Erasing Speed Memory
The cruise control set speed is
erased from memory if
Iis
pressed or if the vehicle is
turned off.

Black plate (39,1)GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-7707482) -
2015 - crc - 1/20/15
Driving and Operating 9-39
Fuel
For diesel engine vehicles, see
“Fuel for Diesel Engines”in the
Duramax diesel supplement.
For gasoline engine vehicles, use of
the recommended fuel is an
important part of the proper
maintenance of this vehicle. When
driving in the U.S. and Canada, to
help keep the engine clean and
maintain optimum vehicle
performance, we recommend using
TOP TIER Detergent Gasolines.
See www.toptiergas.com for a list of
TOP TIER Detergent Gasolines.
If the vehicle has a yellow fuel cap,
E85 or FlexFuel can be used in the
vehicle. See E85 or FlexFuel on
page 9-40.
Use regular unleaded gasoline
meeting ASTM specification D4814
with a posted octane rating of 87 or
higher. Do not use gasoline with an
octane rating below 87; as it may
cause engine damage and will lower
fuel economy.
Use of Seasonal Fuels
Use summer and winter fuels in the
appropriate season. The fuels
industry automatically modifies the fuel for the appropriate season.
If fuel is left in the vehicle tank for
long periods of time, driving or
starting could be affected. Drive the
vehicle until the fuel is at one-half
tank or less, then refuel with the
current seasonal fuel.
Prohibited Fuels
Gasolines containing oxygenates
such as ethers and ethanol, as well
as reformulated gasolines, are
available in some cities. If these
gasolines comply with the
previously 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
FlexFuel vehicles.
{Caution
Do not use fuel containing
methanol. It can corrode metal
parts in the fuel system and also
damage plastic and rubber parts.
(Continued)