light GMC SAFARI 2003 Workshop Manual
[x] Cancel search | Manufacturer: GMC, Model Year: 2003, Model line: SAFARI, Model: GMC SAFARI 2003Pages: 376, PDF Size: 2.25 MB
Page 205 of 376

Tow/Haul Mode
The tow/haul mode is a feature that assists when pulling
a heavy trailer. The purpose of the tow/haul mode is:
to reduce the frequency of shifts when pulling a
heavy trailer.
to provide the same shift feel when pulling a heavy
trailer as when the vehicle is unloaded.
to reduce the need to change throttle position when
pulling a heavy trailer.
This feature is turned on or off by pressing a button on
the column shift lever. When the feature is on, a
light on the instrument panel will illuminate to indicate
that the tow/haul mode has been selected.
SeeTow/Haul Mode Light on page 3-35. The tow/haul
mode is automatically turned off each time the vehicle is
started.
The tow/haul mode is most effective when the vehicle
and trailer combined weight is at least 75% of the Gross
Vehicle Weight Rating (GVWR) and the maximum
trailer weight rating for the vehicle.The tow/haul mode for hauling a heavy trailer is most
useful under the following conditions:
When driving through hilly terrain at speeds below
55 mph (88 km/h).
When driving in low speed or stop and go traffic
below 55 mph (88 km/h).
When driving in parking lots.
Operating in the tow/haul mode when not pulling a
heavy trailer will not cause damage to the vehicle, but
you may experience reduced fuel economy and
undesirable performance from the engine and
transmission. The tow/haul mode should be used only
when pulling a heavy trailer.
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.
The following chart shows how much your trailer can
weigh, based upon your vehicle model and options.
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Page 212 of 376

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 over ll),
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
If you have the optional trailering package, your vehicle
will have an eight-wire harness, including the center
high-mounted stoplamp battery feed wire. The harness
is stored on the passenger’s side of the vehicle near
the rear wheel well. This harness has a 30 amp battery
feed wire and no connector, and should be wired by
a quali ed electrical technician. After choosing an
aftermarket trailer mating connector pair, have the
technician attach one connector to the eight-wire trailer
harness and the other connector to the wiring harness
on the trailer. Be sure the wiring harness on the trailer is
taped or strapped to the trailer’s frame rail and leave
it loose enough so the wiring doesn’t bend or break, but
not so loose that it drags on the ground. The eight-wire
harness must be routed out of your vehicle betweenthe rear door and the oor, with enough of the harness
left on both sides so that the trailer or the body won’t
pull it. If you do not have the optional trailering package,
your vehicle will still have a trailering harness. The
harness is located near the passenger’s side rear wheel
well. It consists of six wires that may be used by
after-market trailer hitch installers.
The technician can use the following color code chart
when connecting the wiring harness to your trailer.
Brown: Rear lamps.
Yellow: Left stoplamp and turn signal.
Dark Green: Right stoplamp and turn signal.
White (Heavy Gage): Ground.
Light Green: Back-up lamps.
White (Light Gage): Center High-Mounted Stoplamp.
Blue: Auxiliary circuit (eight-wire harness only).
Orange: Fused auxiliary (eight-wire harness only).
Store the harness in its original place. Wrap the
harness together and tie it neatly so it won’t
be damaged.
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Page 220 of 376

To remove the fuel cap, turn it slowly to the left
(counterclockwise). The fuel cap has a spring in it; if
you let go of the cap too soon, it will spring back to the
right.
{CAUTION:
If you get fuel on yourself and then something
ignites it, you could be badly burned. Fuel
canspray out on you if you open the fuel cap
too quickly. This spray can happen if your tank
is nearly full, and is more likely in hot weather.
Open the fuel cap slowly and wait for any
“hiss” noise to stop. Then unscrew the cap all
the way.
Be careful not to spill fuel. Clean fuel from painted
surfaces as soon as possible. SeeCleaning the Outside
of Your Vehicle on page 5-79. Whenfilling the tank
do not overfill by squeezing in much more fuel after the
pump shuts off.When you put the fuel cap back on, turn it to the right
(clockwise) until you hear a clicking sound. Make
sure you fully install the cap. The diagnostic system can
determine if the fuel cap has been left off or improperly
installed. This would allow fuel to evaporate into the
atmosphere. SeeMalfunction Indicator Lamp on
page 3-30.
Notice:If you need a new fuel cap, be sure to get
the right type. Your dealer can get one for you. If you
get the wrong type, it may not t properly. This may
cause your malfunction indicator lamp to light and
may damage your fuel tank and emissions system.
See“Malfunction Indicator Lamp”in the Index.
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Page 234 of 376

How to Inspect the Engine Air
Cleaner/Filter
To inspect the engine air cleaner/filter remove thefilter
from the vehicle and lightly shakefilter to release
loose dust and dirt. If thefilter remains caked with dirt, a
newfilter is required.
To inspect or replace thefilter, do the following:
1. Unsnap both clips on the cover.
2. Remove the cover.
3. Change thefilter.
4. Snap both clips to secure the engine air
cleaner/filter cover.
{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 back res. If it isn’t there
and the engine back res, you could be burned.
Don’t 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 back re 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’re driving.
Automatic Transmission Fluid
When to Check and Change
A good time to check your automatic transmissionfluid
level is when the engine oil is changed.
Change both thefluid andfilter every 15,000 miles
(25 000 km) 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 you do not use your vehicle under any of these
conditions, change thefluid andfilter every 50,000 miles
(83 000 km).
SeePart A: Scheduled Maintenance Services on
page 6-4.
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How to Add Fluid
Refer to the Maintenance Schedule to determine what
kind of transmissionfluid to use. SeePart D:
Recommended Fluids and Lubricants on page 6-34.
Addfluid only after checking the transmissionfluid while
it is hot. (A cold check is used only as a reference.) If
thefluid level is low, add only enough of the properfluid
to bring the level up to the HOT area for a hot check.
It doesn’t take muchfluid, generally less than one pint
(0.5 L).Don’t overfill.
Notice:We recommend you use only uid labeled
DEXRON
®-III, because uid with that label is
made especially for your automatic transmission.
Damage caused by uid other than DEXRON
®-III is
not covered by your new vehicle warranty.
•After addingfluid, recheck thefluid level as
described under“How to Check.”
•When the correctfluid level is obtained, push the
dipstick back in all the way; thenflip the handle
down to lock the dipstick in place.
Engine Coolant
The cooling system in your vehicle isfilled with
DEX-COOL®engine coolant. This coolant is designed
to remain in your vehicle for 5 years or 150,000 miles
(240 000 km), whichever occursfirst, 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 5-28.
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:When adding coolant, it is important that
you use only DEX-COOL
®(silicate-free) coolant.
If coolant other than DEX-COOL®is added to
the system, premature engine, heater core or
radiator corrosion may result. In addition, the engine
coolant will require change sooner -- at 30,000 miles
(50,000 km) or 24 months, whichever occurs rst.
Damage caused by the use of coolant other
than DEX-COOL
®is not covered by your new vehicle
warranty.
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