transmission GMC SAVANA 2007 User Guide

Hill and Mountain Roads
Driving on steep hills or mountains is different
from driving in flat or rolling terrain.If you drive regularly in steep country, or if you are
planning to visit there, here are some tips that
can make your trips safer and more enjoyable.
•Keep your vehicle in good shape. Check
all fluid levels and also the brakes, tires,
cooling system, and transmission. These parts
can work hard on mountain roads.
{CAUTION:
If you do not shift down, your brakes
could get so hot that they would not work
well. You would then have poor braking or
even none going down a hill. You could
crash. Shift down to let your engine assist
your brakes on a steep downhill slope.
252

{CAUTION:
Coasting downhill in NEUTRAL (N) or with
the ignition off is dangerous. Your brakes
will have to do all the work of slowing
down. They could get so hot that they
would not work well. You would then have
poor braking or even none going down a
hill. You could crash. Always have your
engine running and your vehicle in gear
when you go downhill.
•Know how to go down hills. The most important
thing to know is this: let your engine do some of
the slowing down. Shift to a lower gear when
you go down a steep or long hill.
•Know how to go uphill. You may want to shift
down to a lower gear. The lower gears help
cool your engine and transmission, and you can
climb the hill better.
•Stay in your own lane when driving on two-lane
roads in hills or mountains. Do not swing wide
or cut across the center of the road. Drive at
speeds that let you stay in your own lane.
•As you go over the top of a hill, be alert. There
could be something in your lane, like a stalled
car or an accident.
•You may see highway signs on mountains that
warn of special problems. Examples are long
grades, passing or no-passing zones, a falling
rocks area, or winding roads. Be alert to these
and take appropriate action.
253

If Your Vehicle is Stuck in Sand,
Mud, Ice, or Snow
In order to free your vehicle when it is stuck,
you will need to spin the wheels, but you do not
want to spin your wheels too fast. The method
known as rocking can help you get out when you
are stuck, but you must use caution.
{CAUTION:
If you let your vehicle’s tires spin at high
speed, they can explode, and you or others
could be injured. And, the transmission or
other parts of the vehicle can overheat.
That could cause an engine compartment
re or other damage. When you are stuck,
spin the wheels as little as possible. Do not
spin the wheels above 35 mph (55 km/h) as
shown on the speedometer.Notice:Spinning the wheels can destroy
parts of your vehicle as well as the tires. If
you spin the wheels too fast while shifting the
transmission back and forth, you can destroy
the transmission.
For information about using tire chains on your
vehicle, seeTire Chains on page 359.
Rocking Your Vehicle to Get It Out
First, turn the steering wheel left and right.
That will clear the area around the front wheels.
Then shift back and forth between REVERSE (R)
and a forward gear, spinning the wheels as
little as possible. Release the accelerator pedal
while you shift, and press lightly on the accelerator
pedal when the transmission is in gear. By
slowly spinning the wheels in the forward and
reverse directions, you will cause a rocking motion
that may free your vehicle. If that does not get
your vehicle out after a few tries, it may need to be
towed out. If your vehicle does need to be
towed out, seeTowing Your Vehicle on page 264.
258

Dinghy Towing
Two-Wheel-Drive Vehicles
Notice:If you tow your vehicle with all
four wheels on the ground, the drivetrain
components could be damaged. The repairs
would not be covered by your warranty.
Do not tow your vehicle with all four wheels
on the ground.
Two-wheel-drive vehicles should not be towed
with all four wheels on the ground.
Two-wheel-drive transmissions have no provisions
for internal lubrication while being towed.
All-Wheel-Drive Vehicles
Your vehicle was not designed to be towed with
all four wheels on the ground. To properly
tow these vehicles, they should be placed on a
platform trailer with all four wheels off the ground.
Notice:Towing an all-wheel-drive vehicle
with all four wheels on the ground, or even
with only two of its wheels on the ground, will
damage drivetrain components. Do not tow
an all-wheel-drive vehicle if any of its wheels
will be on the ground.
Dolly Towing
Rear Towing (Rear Wheels Off the Ground)
Two-Wheel-Drive Vehicles
Use the following procedure to tow your vehicle
from the rear:
1. Drive the vehicle onto the dolly.
2. Firmly set the parking brake. SeeParking
Brake on page 128for more information.
3. Put the automatic transmission in PARK (P).
4. Follow the dolly manufacturer’s instructions
to attach and secure the vehicle being
towed to the dolly and then the loaded dolly to
the tow vehicle. Make sure the wheels are
straight before towing.
Use an adequate clamping device to ensure
that the front wheels are locked into the
straight position.
265

Tow/Haul Mode
Tow/haul is designed to assist while your vehicle
is pulling a large or heavy load or trailer.
Tow/haul is most useful while pulling such a load
in rolling terrain, in stop-and-go traffic, or when
you need improved low-speed control, such
as when parking. The purpose of the tow/haul
mode is to:
•Reduce the frequency and improve the
predictability of transmission shifts,
•provide the same solid shift feel when pulling
a heavy load as when the vehicle is unloaded,
•improve control of vehicle speed while
requiring less throttle pedal activity.
Press this button
located to the right of
the steering wheel
on the instrument panel
to turn tow/haul
mode on and off.While activated, the
indicator light on the
instrument panel
will be on.
Tow/haul mode will turn off automatically when the
ignition is turned off. SeeTow/Haul Mode Light
on page 185.
Tow/haul is 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 this
section.
Driving with tow/haul activated without a heavy
load will cause reduced fuel economy and
unpleasant engine and transmission driving
characteristics, but will not cause damage.
268

Turn Signals When Towing a Trailer
When you tow a trailer, your vehicle has to have
extra wiring and a heavy-duty turn signal
flasher (included in the optional trailering package).
The arrows on your instrument panel will flash
whenever you signal a turn or lane change.
Properly hooked up, the trailer lamps will also flash,
telling other drivers you’re about to turn, change
lanes or stop.
When towing a trailer, the arrows on your
instrument panel will flash for turns even if the bulbs
on the trailer are burned out. Thus, you may think
drivers behind you are seeing your signal when
they are not. It’s important to check occasionally to
be sure the trailer bulbs are still working.
Driving On Grades
Reduce speed and shift to a lower gearbefore
you start down a long or steep downgrade. If you
don’t shift down, you might have to use your
brakes so much that they would get hot and no
longer work well.
You can tow in DRIVE (D). You may want to shift
the transmission to THIRD (3) or a lower gear
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 you
turn your engine off immediately after towing at high
altitude on steep uphill grades, your 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
PARK (P) for a few minutes before turning the
engine off. If you do get the overheat warning, see
Engine Overheating on page 309.
280

Maintenance When Trailer Towing
Your vehicle will need service more often when
you’re pulling a trailer. See the Maintenance
Schedule for more on this. Things that are
especially important in trailer operation are
automatic transmission fluid (don’t overfill), engine
oil, axle lubricant, belt, cooling system and brake
system. Each of these is covered in this manual,
and the Index will help you find them quickly.
If you’re trailering, it’s a good idea to review these
sections before you start your 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 seven-wire harness assembly at
the rear of the vehicle and a four-wire
harness assembly under the left hand side
of the instrument panel. The seven-wire
harness assembly is taped together and
located in a frame pocket at the driver side
rear left corner of the frame.The seven-wire harness includes a 30-amp feed
wire. Both harnesses come without connectors and
should be wired by a qualified electrical technician.
The technician can use the following color code
chart when connecting the wiring harness to
your trailer and trailer brake controller.
Seven-Wire Harness
•Light Green: Back-up lamps
•Brown: Parking lamps
•Yellow: Left stoplamp and turn signal
•Dark Green: Right stoplamp and turn signal
•Dark Blue: Use for electric trailer brakes
•Red/Black Stripe: Trailer accessory
•White (heavy gage): Ground wire
Four-Wire Harness (Trailer Brake Controller)
•Black: Ground
•Red/White Stripe: Fused Battery
•Dark Blue: Trailer Brake Feed
•Light Blue: Fused Stoplamp/CHMSL
282

Service........................................................ 286
Accessories and Modifications................... 286
California Proposition 65 Warning.............. 286
Doing Your Own Service Work.................. 287
Adding Equipment to the Outside
of Your Vehicle...................................... 287
Fuel............................................................. 288
Gasoline Octane........................................ 288
Gasoline Specifications.............................. 288
California Fuel........................................... 289
Additives................................................... 289
Fuel E85 (85% Ethanol)............................ 290
Fuels in Foreign Countries........................ 291
Filling the Tank......................................... 292
Filling a Portable Fuel Container............... 294
Checking Things Under the Hood.............. 294
Hood Release........................................... 295
Engine Compartment Overview.................. 296
Engine Oil (Gasoline Engine).................... 297Engine Oil Life System
(Gasoline Engine).................................. 300
Engine Air Cleaner/Filter............................ 302
Automatic Transmission Fluid.................... 303
Engine Coolant.......................................... 306
Radiator Pressure Cap.............................. 309
Engine Overheating................................... 309
Cooling System......................................... 311
Engine Fan Noise..................................... 317
Power Steering Fluid ................................. 317
Windshield Washer Fluid........................... 318
Brakes...................................................... 319
Battery...................................................... 323
Jump Starting............................................ 324
All-Wheel Drive........................................... 330
Rear Axle.................................................... 331
Front Axle................................................... 331
Section 5 Service and Appearance Care
283

A. Battery. SeeBattery on page 323.
B. Radiator Pressure Cap. SeeRadiator Pressure
Cap on page 309.
C. Coolant Recovery Tank. SeeCooling System
on page 311.
D. Automatic Transmission Fluid Dipstick. See
“Checking the Fluid Level” underAutomatic
Transmission Fluid on page 303.
E. Engine Oil Fill Cap. See “When to Add Engine
Oil” underEngine Oil (Gasoline Engine) on
page 297.
F. Engine Oil Dipstick. See “Checking Engine Oil”
underEngine Oil (Gasoline Engine) on
page 297.
G. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 302.
H. Power Steering Fluid Reservoir. SeePower
Steering Fluid on page 317.
I. Brake Master Cylinder Reservoir. See “Brake
Fluid” underBrakes on page 319.
J. Windshield Washer Fluid Reservoir. See
“Adding Washer Fluid” underWindshield
Washer Fluid on page 318.Engine Oil (Gasoline Engine)
If your vehicle has a diesel engine, see “Engine
Oil” in the DURAMAX®Diesel Engine Supplement.
Checking Engine Oil
It is a good idea to check the engine oil every time
you get fuel. In order to get an accurate reading,
the oil must be warm and the vehicle must be
on level ground.
The engine oil dipstick handle is a yellow loop.
SeeEngine Compartment Overview on page 296
for the location of the engine oil dipstick.
1. Turn off the engine and give the oil several
minutes to drain back into the oil pan. If you
do not do this, the oil dipstick might not
show the actual level.
2. Pull out the dipstick and clean it with a paper
towel or cloth, then push it back in all the
way. Remove it again, keeping the tip down,
and check the level.
297

3. Clean the engine air cleaner/filter housing.
4. Inspect or replace the engine air cleaner/filter.
Make sure that the filter fits properly into
the housing.
5. Reinstall the cover and fasten the
retaining clips.
{CAUTION:
Operating the engine with the air cleaner/
lter off can cause you or others to be
burned. The air cleaner not only cleans the
air; it helps to stop ames if the engine
backres. If it is not there and the engine
backres, you could be burned. Do not
drive with it off, and be careful working on
the engine with the air cleaner/lter off.
Notice:If the air cleaner/lter is off, a backre
can cause a damaging engine re. And, dirt
can easily get into your engine, which will
damage it. Always have the air cleaner/lter in
place when you are driving.
Automatic Transmission Fluid
When to Check and Change Automatic
Transmission Fluid
A good time to check your automatic transmission
fluid level is when the engine oil is changed.
Change the fluid and filter at the intervals listed in
Additional Required Services (Gasoline Engine)
on page 402, and be sure to use the transmission
fluid listed inRecommended Fluids and
Lubricants on page 409.
303