automatic transmission GMC SAVANA PASSENGER 2015 User Guide

Black plate (27,1)GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-7707482) -
2015 - crc - 6/3/14
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 5-20.
Also see “Tow/Haul Mode” under
Towing Equipment on page 9-50.
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 5-35.
See Towing Equipment on
page 9-50.
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 - 6/3/14
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 10-2.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 - 6/3/14
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 5-35.
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 (46,1)GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-7707482) -
2015 - crc - 6/3/14
9-46 Driving and Operating
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
transmission in P (Park) for a few
minutes before turning the engine
off. If the overheat warning comes
on, seeEngine Overheating on
page 10-18.
Parking on Hills
{Warning
Parking the vehicle on a hill with
the trailer attached can be
dangerous. If something goes
wrong, the rig could start to move.
People can be injured, and both
the vehicle and the trailer can be
damaged. When possible, always
park the rig on a flat surface. If parking the rig on a hill:
1. Press the brake pedal, but do
not shift into P (Park) yet. Turn
the wheels into the curb if facing
downhill or into traffic if facing
uphill.
2. Have someone place chocks under the trailer wheels.
3. When the wheel chocks are in place, release the regular brakes
until the chocks absorb the load.
4. Reapply the brake pedal. Then apply the parking brake and shift
into P (Park).
5. Release the brake pedal.
Leaving After Parking on a Hill
1. Apply and hold the brake pedal.
2. Start the engine.
3. Shift into a gear.
4. Release the parking brake.
5. Let up on the brake pedal.
6. Drive slowly until the trailer is clear of the chocks. 7. Stop and have someone pick up
and store the chocks.
Maintenance when Trailer
Towing
The vehicle needs service more
often when pulling a trailer. See
Maintenance Schedule on
page 11-3. Things that are
especially important in trailer
operation are automatic
transmission fluid, engine oil, axle
lubricant, belts, cooling system, and
brake system. It is a good idea to
inspect these before and during
the trip.
Check periodically to see that all
hitch nuts and bolts are tight.
Trailer Towing
If the vehicle has a diesel engine,
see the Duramax diesel
supplement.

Black plate (1,1)GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-7707482) -
2015 - crc - 6/3/14
Vehicle Care 10-1
Vehicle Care
General Information
General Information . . . . . . . . . . 10-2
California Proposition65 Warning . . . . . . . . . . . . . . . . . 10-2
California Perchlorate Materials Requirements . . . . 10-2
Accessories and Modifications . . . . . . . . . . . . . . . 10-2
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 10-3
Hood . . . . . . . . . . . . . . . . . . . . . . . . 10-4
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . 10-5
Engine Oil . . . . . . . . . . . . . . . . . . . 10-6
Engine Oil Life System . . . . . . 10-8
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . 10-9
Engine Air Cleaner/Filter . . . . 10-12
Cooling System . . . . . . . . . . . . 10-13
Engine Coolant . . . . . . . . . . . . . 10-14
Engine Overheating . . . . . . . . 10-18
Engine Fan . . . . . . . . . . . . . . . . . 10-19
Power Steering Fluid . . . . . . . 10-20
Washer Fluid . . . . . . . . . . . . . . . 10-21 Brakes . . . . . . . . . . . . . . . . . . . . . 10-21
Brake Fluid . . . . . . . . . . . . . . . . . 10-22
Battery . . . . . . . . . . . . . . . . . . . . . 10-24
Rear Axle . . . . . . . . . . . . . . . . . . 10-24
Noise Control System . . . . . . 10-25
Starter Switch Check . . . . . . . 10-26
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . 10-26
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . 10-27
Park Brake and P (Park) Mechanism Check . . . . . . . . 10-27
Wiper Blade Replacement . . . . . . . . . . . . . . 10-27
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . 10-28
Bulb Replacement
Bulb Replacement . . . . . . . . . . 10-28
Halogen Bulbs . . . . . . . . . . . . . . 10-28
Headlamps . . . . . . . . . . . . . . . . . 10-29
Front Turn Signal,Sidemarker, and Parking
Lamps . . . . . . . . . . . . . . . . . . . . 10-30
Taillamps . . . . . . . . . . . . . . . . . . . 10-31 Center High-Mounted
Stoplamp (CHMSL) . . . . . . . 10-32
License Plate Lamp . . . . . . . . 10-33
Replacement Bulbs . . . . . . . . . 10-33
Electrical System
Electrical System Overload . . . . . . . . . . . . . . . . . . 10-34
Fuses and Circuit Breakers . . . . . . . . . . . . . . . . . . 10-34
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-34
Floor Console Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-38
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . 10-40
All-Season Tires . . . . . . . . . . . . 10-41
Winter Tires . . . . . . . . . . . . . . . . 10-42
All-Terrain Tires . . . . . . . . . . . . 10-42
Tire Sidewall Labeling . . . . . . 10-42
Tire Designations . . . . . . . . . . . 10-45
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . 10-46
Tire Pressure . . . . . . . . . . . . . . . 10-49
Tire Pressure Monitor System . . . . . . . . . . . . . . . . . . . 10-50
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . 10-51

Black plate (6,1)GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-7707482) -
2015 - crc - 6/3/14
10-6 Vehicle Care
1.Battery on page 10-24.
2. Radiator Pressure Cap. See Cooling System on page 10-13.
3. Coolant Recovery Tank. See Cooling System on page 10-13.
4. Automatic Transmission Fluid Dipstick. See “Checking the
Fluid Level” underAutomatic
Transmission Fluid on
page 10-9.
5. Engine Oil Fill Cap. See “When
to Add Engine Oil” underEngine
Oil on page 10-6.
6. Engine Oil Dipstick. See “Checking Engine Oil” under
Engine Oil on page 10-6.
7. Engine Air Cleaner/Filter on
page 10-12.
8. Power Steering Fluid Reservoir. See Power Steering Fluid on
page 10-20.
9. Brake Master Cylinder Reservoir. See Brake Fluid on
page 10-22. 10. Windshield Washer Fluid
Reservoir. See “Adding Washer
Fluid” under Washer Fluid on
page 10-21.
Engine Oil
For diesel engine vehicles, see
“Engine Oil” in the Duramax diesel
supplement.
To ensure proper engine
performance and long life, careful
attention must be paid to engine oil.
Following these simple, but
important steps will help protect
your investment:
.Always use engine oil approved
to the proper specification and of
the proper viscosity grade. See
“Selecting the Right Engine Oil”
in this section.
.Check the engine oil level
regularly and maintain the
proper oil level. See “Checking
Engine Oil” and“When to Add
Engine Oil” in this section.
.Change the engine oil at the
appropriate time. See Engine Oil
Life System on page 10-8.
.Always dispose of engine oil
properly. See “What to Do with
Used Oil” in this section.
Checking Engine Oil
It is a good idea to check the engine
oil level at each fuel fill. In order to
get an accurate reading, the vehicle
must be on level ground. The
engine oil dipstick handle is a loop.
SeeEngine Compartment Overview
on page 10-5 for the location of the
engine oil dipstick.
Obtaining an accurate oil level
reading is essential:
1. If the engine has been running recently, turn off the engine and
allow several minutes for the oil
to drain back into the oil pan.
Checking the oil level too soon
after engine shutoff will not
provide an accurate oil level
reading.

Black plate (9,1)GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-7707482) -
2015 - crc - 6/3/14
Vehicle Care 10-9
the oil life system to work properly,
the system must be reset every time
the oil is changed.
When the system has calculated
that oil life has been diminished, it
indicates that an oil change is
necessary. A CHANGE ENGINE
OIL SOON message comes on. See
Engine Oil Messages on page 5-30.
Change the oil as soon as possible
within the next 1 000 km (600 mi).
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 key to ON/RUN
with the engine off.
2. Fully press and release the accelerator pedal slowly three
times within five seconds.
3. Turn the key to LOCK/OFF.
If the CHANGE ENGINE OIL SOON
message comes back on when the
vehicle is started, the engine oil life
system has not reset. Repeat the
procedure.
Automatic Transmission
Fluid
When to Check and Change
Automatic Transmission Fluid
It is usually not necessary to check
the transmission fluid level. The only
reason for fluid loss is a
transmission leak or overheated
transmission. If a small leak is
suspected, use the following
procedures to check the fluid level.
However, if there is a large leak, it
may be necessary to have the
vehicle towed to a dealer and have
it repaired before driving the vehicle
further.
Change the fluid and filter at the
intervals listed in Maintenance
Schedule on page 11-3, and be sure
to use the transmission fluid listed in
Recommended Fluids and
Lubricants on page 11-10.

Black plate (10,1)GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-7707482) -
2015 - crc - 6/3/14
10-10 Vehicle Care
How to Check Automatic
Transmission Fluid
Because this operation can be
difficult, it is recommended to have
this check done at your dealer,
which can monitor the transmission
temperature. The transmission fluid
level increases with temperature. To
obtain a highly accurate fluid level
check, the transmission temperature
must be measured.
If it is decided to check the fluid
level, be sure to follow all the
instructions here, or a false reading
on the dipstick may occur.
{Caution
Too much or too little fluid can
damage the transmission. Too
much can mean that some of the
fluid could come out and fall on
hot engine parts or exhaust
system parts, starting a fire. Too
little fluid could cause the(Continued)
Caution (Continued)
transmission to overheat. Be sure
to get an accurate reading if
checking the transmission fluid.
Wait at least 30 minutes with the
engine off, before checking the
transmission fluid level if the vehicle
has been driven:
.In hot weather, when outside
temperatures are above 32°C
(90°F).
.The vehicle is heavily loaded.
.At high speed for quite a while in
hot weather.
.In heavy traffic and hot weather.
.While pulling a trailer.
After driving under these conditions,
a hot check can be performed. The
fluid should be hot, which is 71°C to
93°C (160°F to 200°F). A cold fluid level check can be
performed after the vehicle has
been sitting for eight hours or more
with the engine off, but this is used
only as a reference. Let the engine
run at idle for five minutes if the
outside temperature is between
15°C to 32°C (60°F to 90°F). Should
the fluid level be low during this cold
check, the fluid must be checked
warm or hot before adding fluid.
If the outside temperature is colder
than 15°C (60°F) or hotter than
32°C (90°F), a cold check cannot be
performed.
A warm fluid level check can be
performed by driving the vehicle
under lightly loaded conditions and
outside temperatures between 10°C
to 27°C (50°F to 80°F). The vehicle
should be driven for at least 24 km
(15 mi) before performing a warm
check. Checking the fluid warm or
hot will give a more accurate
reading of the fluid level than a cold
check.

Black plate (12,1)GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-7707482) -
2015 - crc - 6/3/14
10-12 Vehicle Care
How to Add Automatic
Transmission Fluid
Refer toRecommended Fluids and
Lubricants on page 11-10 to
determine what kind of transmission
fluid to use.
1. WARM Range
2. HOT Range
Using a funnel, add fluid down the
transmission dipstick tube only after
checking the transmission fluid
while it is warm or hot. A cold check
is used only as a reference. If the
fluid level is low, add only enough of
the proper fluid to bring the level up
to the middle of the WARM (1) or
HOT (2) range depending on the
ambient temperature and prior
driving conditions. Refer to “How to
Check Automatic Transmission Fluid”
earlier in this section for
instructions on driving to achieve
warm or hot transmission fluid.
It does not take much fluid,
generally less than 0.5 L (1 pt). Do
not overfill.
{Caution
Use of the incorrect automatic
transmission fluid may damage
the vehicle, and the damage may
not be covered by the vehicle
warranty. Always use the
automatic transmission fluid listed
in Recommended Fluids and
Lubricants on page 11-10.
.After adding fluid, recheck the
fluid level as described under
“How to Check Automatic
Transmission Fluid,” earlier in
this section.
.When the correct fluid level is
obtained, push the dipstick back
in all the way; then flip the
handle down to lock the dipstick
in place.
Engine Air Cleaner/Filter
The engine air cleaner/filter is near
the center of the engine
compartment. See Engine
Compartment Overview on
page 10-5.

Black plate (26,1)GMC Savana Owner Manual (GMNA-Localizing-U.S./Canada-7707482) -
2015 - crc - 6/3/14
10-26 Vehicle Care
Engine:
.Removal or rendering engine
speed governor, if the vehicle
has one, inoperative so as to
allow engine speed to exceed
manufacturer specifications.
Fan and Drive:
.Removal of fan clutch, if the
vehicle has one, or rendering
clutch inoperative.
.Removal of the fan shroud, if the
vehicle has one.
Air Intake:
.Removal of the air cleaner
silencer.
.Modification of the air cleaner.
Exhaust:
.Removal of the muffler and/or
resonator.
.Removal of the exhaust pipes
and exhaust pipe clamps. Fuel Operated Heater (FOH)
—
Diesel Engine:
.Removal of the muffler.
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. Apply both the parking brake and the regular brake.
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. Apply the parking brake. Be ready to apply the regular brake
immediately if the vehicle begins
to move.