Black plate (47,1)GMC Savana Owner Manual - 2012 - 2nd - 11/11/11
Driving and Operating 9-47
Driving with a Trailer
{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.
Engine exhaust contains carbon
monoxide (CO) which cannot be
seen or smelled. It can cause
unconsciousness and even death.
To maximize safety when towing
a trailer:
.Have the exhaust system
inspected for leaks and make
necessary repairs before
starting a trip.
.Never 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.
.Adjust the Climate Control
system to a setting that
brings in only outside air and
set the fan speed to the
highest setting. See Climate
Control System in the Index.
For more information about
carbon monoxide, see Engine
Exhaust on page 9‑24. Towing a trailer requires a certain
amount of experience. Get to know
the rig before setting out for the
open road. Get acquainted with the
feel of handling and braking with the
added weight of the trailer. And
always keep in mind that the vehicle
you are driving is now longer and
not as responsive as the vehicle is
by itself.
Before starting, check all trailer
hitch parts and attachments, safety
chains, electrical connectors, lamps,
tires and mirror adjustments. If the
trailer has electric brakes, start the
vehicle and trailer moving and then
apply the trailer brake controller by
hand to be sure the brakes are
working. This checks the electrical
connection at the same time.
During the trip, check occasionally
to be sure that the load is secure,
and that the lamps and any trailer
brakes are still working.
Black plate (48,1)GMC Savana Owner Manual - 2012 - 2nd - 11/11/11
9-48 Driving and Operating
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 situations
that require heavy braking and
sudden turns.
Passing
More passing distance is needed
when towing a trailer. Because the
rig is longer, 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. Then, to move
the trailer to the left, move that hand
to the 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.
Turn Signals When Towing a
Trailer
The arrows on the instrument panel
flash whenever signaling a turn or
lane change. Properly hooked up,
the trailer lamps also flash, telling
other drivers the vehicle is turning,
changing lanes or stopping. When towing a trailer, the arrows on
the instrument panel flash for turns
even if the bulbs on the trailer are
burned out. For this reason you may
think other drivers are seeing the
signal when they are not. 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
beforestarting down a
long or steep downgrade. If the
transmission is not shifted down, the
brakes might have to be used so
much that they would get hot and no
longer work well.
The vehicle 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.
Black plate (49,1)GMC Savana Owner Manual - 2012 - 2nd - 11/11/11
Driving and Operating 9-49
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)
for a few minutes before turning the
engine off. If the overheat warning
comes on, seeEngine Overheating
on page 10‑23.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 the transmission 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 brake pedal
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.
Black plate (50,1)GMC Savana Owner Manual - 2012 - 2nd - 11/11/11
9-50 Driving and Operating
Leaving After Parking on a Hill
1. Apply and hold the brake pedalwhile you:
1.1. Start the engine.
1.2. Shift into a gear.
1.3. Release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. 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 this
manual's Maintenance Schedule or
Index for more information. 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 for more information.
{WARNING
The driver can lose control when
pulling a trailer if the correct
equipment is not used or the
vehicle is not driven properly. For
example, if the trailer is too
heavy, the brakes may not work
well —or even at all. The driver
and passengers could be
seriously injured. The vehicle may
also be damaged; the resulting
repairs would not be covered by
the vehicle warranty. Pull a trailer
only if all the steps in this section
have been followed. Ask your
dealer for advice and information
about towing a trailer with the
vehicle.
Black plate (51,1)GMC Savana Owner Manual - 2012 - 2nd - 11/11/11
Driving and Operating 9-51
Notice:Pulling a trailer
improperly can damage the
vehicle and result in costly
repairs not covered by the vehicle
warranty. To pull a trailer
correctly, follow the advice in this
section and see your dealer for
important information about
towing a trailer with the vehicle.
To identify the trailering capacity
of the vehicle, read the information
in “Weight of the Trailer” that
appears later in this section.
Trailering is different than just
driving the vehicle by itself.
Trailering means changes in
handling, acceleration, braking,
durability, and fuel economy.
Successful, safe trailering takes
correct equipment, and it has to be
used properly. The following information has many
time-tested, important trailering tips
and safety rules. Many of these are
important for your safety and that of
your passengers. So please read
this section carefully before pulling a
trailer.
Weight of the Trailer
How heavy can a trailer safely be?
It depends on how the rig is used.
For example, speed, altitude, road
grades, outside temperature, and
how much the vehicle is used to pull
a trailer are all important. It can
depend on any special equipment
on the vehicle, and the amount of
tongue weight the vehicle can carry.
See
“Weight of the Trailer Tongue”
later in this section for more
information. Maximum trailer weight is calculated
assuming only the driver is in the
tow vehicle and it has all the
required trailering equipment. The
weight of additional optional
equipment, passengers,and cargo in
the tow vehicle must be subtracted
from the maximum trailer weight.
Use the following chart to determine
how much the vehicle can weigh,
based upon the vehicle model and
options.
Black plate (54,1)GMC Savana Owner Manual - 2012 - 2nd - 11/11/11
9-54 Driving and Operating
Ask your dealer for our trailering
information or advice, or write us at
our Customer Assistance Offices.
SeeCustomer Assistance Offices
on page 13‑3 for more information.
Weight of the Trailer Tongue
The tongue load (A) of any trailer is
an important weight to measure
because it affects the total gross
weight of the vehicle. The Gross
Vehicle Weight (GVW) includes the
curb weight of the vehicle, any
cargo carried in it, and the people
who will be riding in the vehicle.
If there are a lot of options,
equipment, passengers, or cargo in
the vehicle, it will reduce the tongue
weight the vehicle can carry, which
will also reduce the trailer weight the
vehicle can tow. If towing a trailer,
the tongue load must be added to
the GVW because the vehicle will
be carrying that weight, too. See
Vehicle Load Limits on page 9‑10
for more information about the
vehicle's maximum load capacity.
The trailer tongue weight (A) should
be 10 percent to 15 percent of the
total loaded trailer weight (B), up to
a maximum of 181 kg (400 lbs) with
a weight carrying hitch. The trailer
tongue weight (A) should be
10 percent to 15 percent of the total
loaded trailer weight (B), up to a
maximum of 454 kg (1,000 lbs) with
a weight distributing hitch.
Do not exceed the maximum
allowable tongue weight for the
vehicle. Choose the shortest hitch
extension that will position the hitch ball closest to the vehicle. This will
help reduce the effect of trailer
tongue weight on the rear axle.
After loading the trailer, weigh
the trailer and then the tongue,
separately, to see if the weights are
proper. If they are not, adjustments
might be made by moving some
items around in the trailer.
Trailering may be limited by the
vehicle's ability to carry tongue
weight. Tongue weight cannot cause
the vehicle to exceed the GVWR
(Gross Vehicle Weight Rating) or
the RGAWR (Rear Gross Axle
Weight Rating). The effect of
additional weight may reduce the
trailering capacity more than the
total of the additional weight.
It is important that the vehicle
does not exceed any of its
ratings
—GCWR, GVWR, RGAWR,
Maximum Trailer Rating or Tongue
Weight. The only way to be sure it is
not exceeding any of these ratings
is to weigh the vehicle and trailer.
Black plate (55,1)GMC Savana Owner Manual - 2012 - 2nd - 11/11/11
Driving and Operating 9-55
Total Weight on the Vehicle's
Tires
Be sure the vehicle tires are inflated
to the upper limit for cold tires.
These numbers can be found on the
Certification label at the rear edge of
the driver door, or seeVehicle Load
Limits on page 9‑10. Make sure not
to go over the GVW limit for the
vehicle, or the GAWR, including the
weight of the trailer tongue. If using
a weight distributing hitch, make
sure not to go over the rear axle
limit before applying the weight
distribution spring bars.
Towing Equipment
Hitches
It is important to have the correct
hitch equipment. Crosswinds, large
trucks going by and rough roads are
a few reasons why the right hitch is
needed.
Weight‐Distributing Hitches
and Weight Carrying Hitches
A. Body to Ground Distance
B. Front of Vehicle
When using a weight-distributing
hitch, the hitch must be adjusted so
the distance (A) remains the same
both before and after coupling the
trailer to the tow vehicle. If a step-bumper hitch will be used,
the bumper could be damaged in
sharp turns. Make sure there
is ample room when turning to avoid
contact between the trailer and the
bumper.
If the loaded trailer being pulled
will weigh more than 2 270 kg
(5,000 lbs), be sure to use a
properly mounted weight-distributing
hitch and sway control of the proper
size. This equipment is very
important for proper vehicle loading
and good handling when driving.
Always use a sway control if the
trailer will weigh more than these
limits. Ask a hitch dealer about sway
controls.
Will any holes need to be made in
the body of the vehicle when a
trailer hitch is installed?
Black plate (57,1)GMC Savana Owner Manual - 2012 - 2nd - 11/11/11
Driving and Operating 9-57
The four-wire harness (without
connector) contains the following
circuits:
.Black: Ground
.Red/White: Battery Feed
.Dark Blue: Trailer Brake Signal
.Light Blue: CHMSL/Stoplamp
Supply Voltage
* If the vehicle is a cutaway with
trailer provisions, a 15 amp fuse will
be shared for both left/stop trailer
turn and right/stop trailer turn
signals. However, the cutaway
lighting connector will have a
10 amp fuse for each signal.
** If the vehicle is a cutaway with
trailer provisions, a 15 amp fuse will
be shared for trailer park lamps and
cutaway rear lighting connector park
lamps. Also, a 10 amp fuse will be
shared for trailer back-up lamps and
cutaway rear lighting connector
back-up lamps.
Tow/Haul Mode
This button is on the instrument
panel, to the right of the steering
wheel.
Pressing this button turns on and off
the Tow/Haul Mode.
This indicator light on the instrument
panel cluster comes on when the
Tow/Haul Mode is on.
Tow/Haul is a feature that assists
when pulling a heavy trailer or a
large or heavy load. See Tow/Haul
Mode on page 9‑32 for more
information. Tow/Haul is designed to be most
effective when the vehicle and
trailer combined weight is at least
75 percent of the vehicle Gross
Combined Weight Rating (GCWR).
See
“Weight of the Trailer” inTrailer
Towing on page 9‑50. Tow/Haul is
most useful under the following
driving conditions:
.When pulling a heavy trailer or a
large or heavy load through
rolling terrain.
.When pulling a heavy trailer or a
large or heavy load in stop and
go traffic.
.When pulling a heavy trailer or a
large or heavy load in busy
parking lots where improved low
speed control of the vehicle is
desired.