transmission GMC SAVANA 2005 User Guide

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 3-39.
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.
Weight of the Trailer
How heavy can a trailer safely be?
It depends on how you plan to use your rig. For example,
speed, altitude, road grades, outside temperature and
how much your vehicle is used to pull a trailer are all
important. And, it can also depend on any special
equipment that you have on your vehicle.
4-38

Driving On Grades
Reduce speed and shift to a lower gearbeforeyou
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, seeEngine Overheating on
page 5-25.
Parking on Hills
{CAUTION:
You really should not park your vehicle, with a
trailer attached, on a hill. If something goes
wrong, your rig could start to move. People
can be injured, and both your vehicle and the
trailer can be damaged.
But if you ever have to park your rig on a hill,
here’s how to do it:
1. Apply your regular brakes, but don’t shift into
PARK (P) yet. Then turn your 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 regular brakes. Then apply your
parking brake and then shift to PARK (P).
5. Release the regular brakes.
4-48

When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal down
while you:
start your 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
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 uid (don’t overll),
engine oil, axle lubricant, belt, cooling system and
brake system. Each of these is covered in this manual,
and the Index will help you nd 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 qualied 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
Orange: 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
4-49

Service............................................................5-3
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside of Your
Vehicle......................................................5-5
Fuel................................................................5-5
Gasoline Octane............................................5-5
Gasoline Specications....................................5-5
California Fuel...............................................5-6
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-7
Filling Your Tank............................................5-8
Filling a Portable Fuel Container.....................5-10
Checking Things Under the Hood....................5-10
Hood Release..............................................5-11
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-13
Engine Oil Life System..................................5-16
Engine Air Cleaner/Filter................................5-18
Automatic Transmission Fluid.........................5-19
Engine Coolant.............................................5-22
Radiator Pressure Cap..................................5-25
Engine Overheating.......................................5-25Cooling System............................................5-27
Engine Fan Noise.........................................5-32
Power Steering Fluid.....................................5-33
Windshield Washer Fluid................................5-34
Brakes........................................................5-35
Battery........................................................5-38
Jump Starting...............................................5-39
All-Wheel Drive..............................................5-43
Rear Axle.......................................................5-44
Front Axle......................................................5-44
Noise Control System.....................................5-45
Tampering with Noise Control System
Prohibited.................................................5-45
Bulb Replacement..........................................5-47
Halogen Bulbs..............................................5-47
Headlamps..................................................5-47
Front Turn Signal, Sidemarker and Parking
Lamps.....................................................5-49
Center High-Mounted Stoplamp (CHMSL).........5-49
Taillamps.....................................................5-50
Replacement Bulbs.......................................5-51
Section 5 Service and Appearance Care
5-1

A. Battery. SeeBattery on page 5-38.
B. Radiator Pressure Cap. SeeRadiator Pressure Cap
on page 5-25.
C. Coolant Recovery Tank. SeeCooling System on
page 5-27.
D. Automatic Transmission Fluid Dipstick. See
“Checking the Fluid Level” underAutomatic
Transmission Fluid on page 5-19.
E. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil on page 5-13.
F. Engine Oil Dipstick. See “Checking Engine Oil”
underEngine Oil on page 5-13.
G. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-18.
H. Power Steering Fluid Reservoir. SeePower Steering
Fluid on page 5-33.
I. Brake Master Cylinder Reservoir. See “Brake Fluid”
underBrakes on page 5-35.
J. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on page 5-34.Engine Oil
Checking Engine Oil
It is a good idea to check your 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. See
Engine Compartment Overview on page 5-12for
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.
5-13

{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 ame 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
A good time to check your automatic transmission uid
level is when the engine oil is changed.
Change both the uid and lter every 50,000 miles
(83,000 km) if the vehicle’s GVWR is over
8,600 lbs (3 901 kg) or if the vehicle is mainly driven
under one or more of these conditions:
In heavy city traffic where the outside temperature
regularly reaches 90°F (32°C) or higher.
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as found in taxi, police or delivery
service.
If your vehicle’s GVWR is not over 8,600 lbs (3 901 kg)
and you do not use your vehicle under any of these
conditions, change the uid and lter every
100,000 miles (166 000 km).
SeeScheduled Maintenance on page 6-4.
5-19

How to Check
Because this operation can be a little difficult, you may
choose to have this done at the dealership service
department.
If you do it yourself, be sure to follow all the instructions
here, or you could get a false reading on the dipstick.
Notice:Too much or too little uid can damage
your transmission. Too much can mean that some
of the uid could come out and fall on hot engine
part or exhaust system parts, starting a re.
Too little uid could cause the transmission to
overheat. Be sure to get an accurate reading if you
check your transmission uid.
Wait at least 30 minutes before checking the
transmission uid level if you have been driving:
When outside temperatures are above 90°F (32°C).
At high speed for quite a while.
In heavy traffic — especially in hot weather.
While pulling a trailer.
To get the right reading, the uid should be
at normal operating temperature, which is
180°F to 200°F (82°C to 93°C).Get the vehicle warmed up by driving about
15 miles (24 km) when outside temperatures are above
50°F (10°C). If it is colder than 50°F (10°C), drive
the vehicle in DRIVE (D) until the engine temperature
gage moves and then remains steady for 10 minutes.
A cold uid check can be made 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 ve minutes if outside
temperatures are 50°F (10°C) or more. If it is colder
than 50°F (10°C), you may have to idle the engine
longer. Should the uid level be low during this cold
check, you must check the uid hot before adding uid.
Checking the uid hot will give you a more accurate
reading of the uid level.
5-20

Checking the Fluid Level
Prepare your vehicle as follows:
Park your vehicle on a level place. Keep the engine
running.
With the parking brake applied, place the shift lever
in PARK (P).
With your foot on the brake pedal, move the shift
lever through each gear range, pausing for about
three seconds in each range. Then, position the shift
lever in PARK (P).
Let the engine run at idle for three minutes or more.
Then, without shutting off the engine, follow these steps:
The transmission dipstick
is located near the center
of the engine compartment
and will be labeled with
the graphic shown.SeeEngine Compartment Overview on page 5-12for
more information on location.
Flip the handle up and then pull out the dipstick and
wipe it with a clean rag or paper towel.
Push it back in all the way, wait three seconds and
then pull it back out again.
Check both sides of the dipstick, and read the lower
level. The uid level must be in the COLD area for
a cold check or in the HOT or cross-hatched
area for a hot check. Be sure to keep the dipstick
pointed down to get an accurate reading.
If the uid level is in the acceptable range, push the
dipstick back in all the way; then ip the handle
down to lock the dipstick in place.
5-21

How to Add Fluid
Refer to the Maintenance Schedule to determine what
kind of transmission uid to use. SeeRecommended
Fluids and Lubricants on page 6-13.
Using a funnel, add uid down the transmission dipstick
tube only after checking the transmission uid while it
is hot. A cold check is used only as a reference.
If the uid level is low, add only enough of the proper
uid to bring the level up to the HOT area for a hot
check. It does not take much uid, generally less than
one pint (0.5 L).Do not overll.
Notice:Use of automatic transmission uid labeled
other than DEXRON
®-III, Approved for the
H-Specication, may damage your vehicle, and the
damages may not be covered by your warranty.
Always use automatic transmission uid labeled
DEXRON
®-III, Approved for the H-Specication.
After adding uid, recheck the uid level as
described under “How to Check,” earlier in
this section.
When the correct uid level is obtained, push the
dipstick back in all the way; then ip the handle
down to lock the dipstick in place.
Engine Coolant
The cooling system in your vehicle is lled with
DEX-COOL®engine coolant. This coolant is designed
to remain in your vehicle for ve years or 150,000 miles
(240 000 km), whichever occurs rst, if you add only
DEX-COOL
®extended life coolant.
The following explains your cooling system and how to
add coolant when it is low. If you have a problem
with engine overheating, seeEngine Overheating on
page 5-25.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
Give freezing protection down to−34°F (−37°C).
Give boiling protection up to 265°F (129°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as they
should.
Notice:Using coolant other than DEX-COOL
®may
cause premature engine, heater core or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at 30,000 miles (50 000 km)
or 24 months, whichever occurs rst. Any repairs
would not be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your vehicle.
5-22

6. Start the engine and let it run until you can feel the
upper radiator hose getting hot. Watch out for the
engine cooling fan.
7. By this time, the coolant level inside the radiator
ller neck may be lower. If the level is lower, add
more of the proper DEX-COOL
®coolant mixture
through the ller neck until the level reaches
the base of the ller neck.
8. Then replace the pressure cap. At any time during
this procedure if coolant begins to ow out of the
ller neck, reinstall the pressure cap.
Engine Fan Noise
Your vehicle has a clutched engine cooling fan. When
the clutch is engaged, the fan spins faster to provide
more air to cool the engine. In most everyday driving
conditions, the fan is spinning slower and the clutch is
not fully engaged. This improves fuel economy and
reduces fan noise. Under heavy vehicle loading, trailer
towing, and/or high outside temperatures, the fan
speed increases as the clutch more fully engages, so
you may hear an increase in fan noise. This is
normal and should not be mistaken as the transmission
slipping or making extra shifts. It is merely the cooling
system functioning properly. The fan will slow down
when additional cooling is not required and the clutch
partially disengages.
You may also hear this fan noise when you start the
engine. It will go away as the fan clutch partially
disengages.
5-32