2010 GMC SAVANA PASSENGER engine

Pulling A Trailer
Here are some important points:
•There are many different laws, including speed limit
restrictions, having to do with trailering. Make sure
the rig will be legal, not only where you live but
also where you will be driving. A good source for
this information can be state or provincial police.
•Consider using a sway control. See “Hitches” later
in this section.
•Do not tow a trailer at all during the first 500 miles
(800 km) the new vehicle is driven. The engine,
axle or other parts could be damaged.
•Then, during the first 500 miles (800 km) that a
trailer is towed, do not drive over 50 mph (80 km/h)
and do not make starts at full throttle. This helps
the engine and other parts of the vehicle wear in at
the heavier loads.
•Vehicles with an automatic transmissions 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.Three important considerations have to do with weight:
•The weight of the trailer
•The weight of the trailer tongue
•The weight on the vehicle’s tires
Also see Tow/Haul later in this section for information
about the Tow/Haul button and the Tow/Haul indicator
light.
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.
5-27

If the loaded trailer being pulled will weigh more than
5,000 lbs (2 270 kg), 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?
If using the wiring provided with the factory-installed
trailering package, no holes need to be made in
the body of the vehicle. However, if an aftermarket hitch
is installed, holes may need to be made in the body.
If holes are made in the body, then be sure to seal the
holes later when the hitch is removed. If the holes
are not sealed, deadly carbon monoxide (CO) from the
engine’s exhaust can get into the vehicle as well as
dirt and water. See “Carbon Monoxide” underEngine
Exhaust on page 3-38.
Safety Chains
Always attach chains between the vehicle and the
trailer. Cross the safety chains under the tongue of the
trailer to help prevent the tongue from contacting
the road if it becomes separated from the hitch. Always
leave just enough slack so the rig can turn. Never
allow safety chains to drag on the ground.
Tow/Haul Mode
Pressing this button at
the end of the shift lever
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. SeeTow/Haul Mode
on page 3-33for more information.
5-33

Tow/Haul is designed to be most effective when the
vehicle and trailer combined weight is at least 75 percent
of the vehicle’s Gross Combined Weight Rating (GCWR).
See “Weight of the Trailer” later in the section. 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.
Operating the vehicle in Tow/Haul when lightly loaded
or with no trailer at all will not cause damage. However,
there is no benefit to the selection of Tow/Haul when
the vehicle is unloaded. Such a selection when unloaded
may result in unpleasant engine and transmission
driving characteristics and reduced fuel economy.
Tow/Haul is recommended only when pulling a heavy
trailer or a large or heavy load.
Trailer Brakes
A loaded trailer that weighs more than 1,500 lbs
(680 kg) needs to have its own brake system that is
adequate for the weight of the trailer. Be sure to read
and follow the instructions for the trailer brakes so
they are installed, adjusted and maintained properly.
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.
•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 3-38
5-34

Driving On Grades
Reduce speed and shift to a lower gearbeforestarting
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.
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 6-33.
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.
5-36

Leaving After Parking on a Hill
1. Apply and hold the brake pedal while you:
•start the engine,
•shift into a gear, and
•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 Wiring Harness
The optional heavy-duty trailer wiring package includes
a wiring harness, with a seven-pin connector at the
rear of the vehicle and a four-wire harness assembly
under the driver side of the instrument panel. The
four-wire harness assembly comes without a connector.
If the vehicle does not have a trailer hitch, the
seven-wire harness assembly with connector is taped
together and located in a frame pocket at the driver side
rear left corner of the frame.
If the vehicle has a trailer hitch, the seven-wire harness
assembly with connector is attached to a bracket on
the hitch platform. In both cases, the seven-wire harness
has a connector and includes a 30-amp feed wire.
5-37

Service............................................................6-3
Accessories and Modifications..........................6-3
California Proposition 65 Warning.....................6-4
California Perchlorate Materials Requirements.....6-4
Doing Your Own Service Work.........................6-4
Adding Equipment to the Outside of the
Vehicle......................................................6-5
Fuel................................................................6-5
Gasoline Octane............................................6-6
Gasoline Specifications....................................6-6
California Fuel...............................................6-7
Additives.......................................................6-7
Fuel E85 (85% Ethanol)..................................6-8
Fuels in Foreign Countries...............................6-9
Filling the Tank............................................6-10
Filling a Portable Fuel Container.....................6-12
Checking Things Under the Hood....................6-12
Hood Release..............................................6-13
Engine Compartment Overview.......................6-14
Engine Oil...................................................6-15
Engine Oil Life System..................................6-18
Engine Air Cleaner/Filter................................6-19
Automatic Transmission Fluid (4-Speed
Transmission)...........................................6-20
Automatic Transmission Fluid (6-Speed
Transmission)...........................................6-23Cooling System............................................6-26
Engine Coolant.............................................6-28
Engine Overheating.......................................6-33
Engine Fan Noise.........................................6-34
Power Steering Fluid.....................................6-35
Windshield Washer Fluid................................6-36
Brakes........................................................6-37
Battery........................................................6-40
Jump Starting...............................................6-41
All-Wheel Drive.............................................
.6-45
Rear Axle.......................................................6-46
Front Axle......................................................6-46
Noise Control System.....................................6-47
Tampering with Noise Control System
Prohibited.................................................6-47
Bulb Replacement..........................................6-48
Halogen Bulbs..............................................6-49
Headlamps..................................................6-49
Front Turn Signal, Sidemarker and Parking
Lamps .....................................................6-51
Center High-Mounted Stoplamp (CHMSL).........6-51
Taillamps.....................................................6-52
License Plate Lamp......................................6-53
Replacement Bulbs.......................................6-53
Windshield Wiper Blade Replacement..............6-54
Section 6 Service and Appearance Care
6-1

Tires..............................................................6-55
Tire Sidewall Labeling...................................6-56
Tire Terminology and Definitions.....................6-60
Inflation - Tire Pressure.................................6-63
Dual Tire Operation.......................................6-64
Tire Pressure Monitor System.........................6-65
Tire Pressure Monitor Operation.....................6-66
Tire Inspection and Rotation...........................6-69
When It Is Time for New Tires.......................6-72
Buying New Tires.........................................6-73
Different Size Tires and Wheels......................6-74
Uniform Tire Quality Grading..........................6-75
Wheel Alignment and Tire Balance..................6-76
Wheel Replacement......................................6-76
Tire Chains..................................................6-78
If a Tire Goes Flat........................................6-79
Changing a Flat Tire.....................................6-80
Removing the Spare Tire and Tools................6-81
Removing the Flat Tire and Installing the
Spare Tire................................................6-85
Secondary Latch System...............................6-92
Storing a Flat or Spare Tire and Tools............6-94
Spare Tire...................................................6-96
Appearance Care............................................6-96
Interior Cleaning...........................................6-96
Fabric/Carpet...............................................6-97Instrument Panel, Vinyl, and Other Plastic
Surfaces..................................................6-98
Care of Safety Belts......................................6-99
Weatherstrips...............................................6-99
Washing Your Vehicle...................................6-99
Cleaning Exterior Lamps/Lenses....................6-100
Finish Care................................................6-100
Windshield and Wiper Blades.......................6-101
Aluminum Wheels.......................................6-101
Tires.........................................................6-102
Sheet Metal Damage...................................6-102
Finish Damage...........................................6-102
Underbody Maintenance...............................6-102
Chemical Paint Spotting...............................6-102
Vehicle Identication.....................................6-103
Vehicle Identification Number (VIN)................6-103
Service Parts Identification Label...................6-103
Electrical System..........................................6-104
Add-On Electrical Equipment.........................6-104
Headlamp Wiring........................................6-104
Windshield Wiper Fuses...............................6-104
Fuses and Circuit Breakers..........................6-104
Floor Console Fuse Block............................6-104
Engine Compartment Fuse Block...................6-106
Capacities and Specications........................6-110
Section 6 Service and Appearance Care
6-2

California Proposition 65 Warning
Most motor vehicles, including this one, contain and/or
emit chemicals known to the State of California to
cause cancer and birth defects or other reproductive
harm. Engine exhaust, many parts and systems, many
fluids, and some component wear by-products
contain and/or emit these chemicals.
California Perchlorate Materials
Requirements
Certain types of automotive applications, such as airbag
initiators, seat belt pretensioners, and lithium batteries
contained in remote keyless transmitters, may
contain perchlorate materials. Special handling may be
necessary. For additional information, see
www.dtsc.ca.gov/hazardouswaste/perchlorate.
Doing Your Own Service Work
{WARNING:
You can be injured and the vehicle could be
damaged if you try to do service work on a vehicle
without knowing enough about it.
•Be sure you have sufficient knowledge,
experience, the proper replacement parts, and
tools before attempting any vehicle
maintenance task.
•Be sure to use the proper nuts, bolts, and
other fasteners. English and metric fasteners
can be easily confused. If the wrong fasteners
are used, parts can later break or fall off. You
could be hurt.
If doing some of your own service work, use the proper
service manual. It tells you much more about how to
service the vehicle than this manual can. To order
the proper service manual, seeService Publications
Ordering Information on page 8-15.
6-4