2000 GMC JIMMY index

4-49
Your vehicle may be able to tow a trailer. To identify
what the vehicle trailering capacity is for your vehicle,
you should read the information in ªWeight of the
Trailerº that appears later in this section.
If yours was built with trailering options, as many are,
it's ready for heavier trailers. But trailering is different
than just driving your vehicle by itself. Trailering means
changes in handling, durability and fuel economy.
Successful, safe trailering takes correct equipment, and
it has to be used properly.
That's the reason for this part. In it are 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 you pull a trailer.
If You Do Decide To Pull A Trailer
If you do, here are some important points:

There are many different laws, including speed limit
restrictions, having to do with trailering. Make sure
your rig will be legal, not only where you live but
also where you'll be driving. A good source for this
information can be state or provincial police.

Consider using a sway control if your trailer will
weigh 2,000 lbs. (900 kg) or less. You should always use a sway control if your trailer
will weigh more than 2,000 lbs. (900 kg). You can
ask a hitch dealer about sway controls.

Don't tow a trailer at all during the first 500 miles
(800 km) your new vehicle is driven. Your engine,
axle or other parts could be damaged.

Then, during the first 500 miles (800 km) that you
tow a trailer, don't drive over 50 mph (80 km/h) and
don't make starts at full throttle. This helps your
engine and other parts of your vehicle wear in at the
heavier loads.

If you have an automatic transmission, you can use
THIRD (3) (or, as you need to, a lower gear) when
towing a trailer. Operating your vehicle in THIRD (3)
when towing a trailer will minimize heat buildup and
extend the life of your transmission. If you have a
manual transmission and you are towing a trailer, it's
better not to use FIFTH (5) gear. Just drive in
FOURTH (4) gear (or, as you need to, a lower gear).
See ªTow/Haul Modeº in the Index.
Three important considerations have to do with weight:

the weight of the trailer,

the weight of the trailer tongue

and the weight on your vehicle's tires.

4-50
Tow/Haul Mode (V6 Engine, Automatic
Transmission Equipped Models) (If Equipped)
The Tow/Haul Mode is a feature that assists when
pulling a heavy trailer. The purpose of the Tow/Haul
Mode is:

Reduce the frequency of shifts when pulling a
heavy trailer.

Provide the same shift feel when pulling a heavy
trailer as when the vehicle is unloaded.

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 floor console. When the
feature is on, a light on the
instrument panel will
illuminate to indicate that
the Tow/Haul Mode has
been selected.See ªTow/Haul Mode Lightº in the Index. 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. See ªGross Vehicle
Weight Ratingº and ªTrailer Weightº in the Index.
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.
Use the Tow/Haul Mode instead of the previous
recommendation to shift to THIRD (3) gear to improve
fuel economy at highway speeds and shift performance
at lower speeds. 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.

4-52 Weight of the Trailer Tongue
The tongue load (A) of any trailer is an important
weight to measure because it affects the total or gross
weight of your vehicle. The Gross Vehicle Weight
(GVW) includes the curb weight of the vehicle, any
cargo you may carry in it, and the people who will be
riding in the vehicle. And if you will tow a trailer, you
must add the tongue load to the GVW because your
vehicle will be carrying that weight, too. See ªLoading
Your Vehicleº in the Index for more information about
your vehicle's maximum load capacity.
If you're using a weight-carrying hitch, the trailer
tongue (A) should weigh 10 percent of the total loaded
trailer weight (B). If you're using a weight
-distributing
hitch, the trailer tongue (A) should weigh 12 percent of
the total loaded trailer weight (B).
After you've loaded your trailer, weigh the trailer and
then the tongue, separately, to see if the weights are
proper. If they aren't, you may be able to get them right
simply by moving some items around in the trailer.
Total Weight on Your Vehicle's Tires
Be sure your vehicle's tires are inflated to the upper
limit for cold tires. You'll find these numbers on the
Certification label at the rear edge of the driver's door or
see ªTire Loadingº in the Index. Then be sure you don't
go over the GVW limit for your vehicle, including the
weight of the trailer tongue.

4-53 Hitches
It's important to have the correct hitch equipment.
Crosswinds, large trucks going by and rough roads are a
few reasons why you'll need the right hitch. Here are
some rules to follow:

If you'll be pulling a trailer that, when loaded, will
weigh more than 3,500 lbs. (1 589 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 you're driving.

Will you have to make any holes in the body of your
vehicle when you install a trailer hitch?
If you do, then be sure to seal the holes later when
you remove the hitch. If you don't seal them, deadly
carbon monoxide (CO) from your exhaust can get
into your vehicle (see ªCarbon Monoxideº in the
Index). Dirt and water can, too.
Safety Chains
You should always attach chains between your vehicle and
your 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. Instructions about
safety chains may be provided by the hitch manufactureror by the trailer manufacturer. Follow the manufacturer's
recommendation for attaching safety chains and do not
attach them to the bumper. Always leave just enough slack
so you can turn with your rig. Never allow safety chains to
drag on the ground.
Trailer Brakes
If your trailer weighs more than 1,000 lbs. (450 kg)
loaded, then it needs its own brakes
-- and they must be
adequate. Be sure to read and follow the instructions for
the trailer brakes so you'll be able to install, adjust and
maintain them properly.
Your trailer's brake system can tap into the vehicle's
hydraulic brake system only if:

The trailer parts can withstand 3,000 psi
(20 650 kPa) of pressure.

The trailer's brake system will use less than
0.02 cubic inch (0.3 cc) of fluid from your vehicle's
master cylinder. Otherwise, both braking systems
won't work well. You could even lose your brakes.
If everything checks out this far, then make the brake
fluid tap at the port on the master cylinder that sends
fluid to the rear brakes. But don't use copper tubing for
this. If you do, it will bend and finally break off. Use
steel brake tubing.

4-54 Driving with a Trailer
CAUTION:
If you have a rear-most window open and you
pull a trailer with your vehicle, carbon monoxide
(CO) could come into your vehicle. You can't see
or smell CO. It can cause unconsciousness or
death. (See ªEngine Exhaustº in the Index.)
To maximize your safety when towing a trailer:

Have your exhaust system inspected for
leaks, and make necessary repairs before
starting on your trip.

Keep the rear
-most windows closed.

If exhaust does come into your vehicle
through a window in the rear or another
opening, drive with your front, main heating
or cooling system on and with the fan on any
speed. This will bring fresh, outside air into
your vehicle. Do not use MAX A/C or
RECIRCULATION because it only
recirculates the air inside your vehicle.
(See ªComfort Controlsº in the Index.)
Towing a trailer requires a certain amount of experience.
Before setting out for the open road, you'll want to get
to know your rig. Acquaint yourself 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 a good deal longer and not nearly as
responsive as your vehicle is by itself.
Before you start, check the trailer hitch and platform
(and attachments), safety chains, electrical connector,
lamps, tires and mirror adjustment. If the trailer has
electric brakes, start your vehicle and trailer moving and
then apply the trailer brake controller by hand to be sure
the brakes are working. This lets you check your
electrical connection at the same time.
During your trip, check occasionally to be sure that the
load is secure, and that the lamps and any trailer brakes
are still working.

4-56 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 gear before 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.On a long uphill grade, shift down and reduce your
speed to around 45 mph (70 km/h) to reduce the
possibility of engine and transmission overheating.
If you have an automatic transmission, you should use
THIRD (3) when towing a trailer. Operating your
vehicle in THIRD (3) when towing a trailer will
minimize heat buildup and extend the life of your
transmission. Or, if you have a manual transmission,
it's better not to use FIFTH (5) gear, just drive in
FOURTH (4) gear (or, as you need to, a lower gear).
See ªTow/Haul Modeº in the Index.
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) (or the
manual transmission out of gear and the parking brake
applied) for a few minutes before turning the engine off.
If you do get the overheat warning, see ªEngine
Overheatingº in the Index.

4-57 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, or into gear for a manual
transmission. 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 into PARK (P), or
REVERSE (R) for a manual transmission.5. If you have a four
-wheel-drive vehicle with an
automatic transfer case, be sure the transfer case is in
a drive gear
-- not in NEUTRAL.
6. Release the regular brakes.
CAUTION:
It can be dangerous to get out of your vehicle if
the shift lever is not fully in PARK (P) with the
parking brake firmly set. Your vehicle can roll.
If you have left the engine running, the vehicle
can move suddenly. You or others could be
injured. To be sure your vehicle won't move, even
when you're on fairly level ground, use the steps
that follow.
Always put the shift lever fully in PARK (P) with
the parking brake firmly set.
If the transfer case on four-wheel drive vehicles is
in NEUTRAL, your vehicle will be free to roll,
even if your shift lever is in PARK (P). So, be
sure the transfer case is in a drive gear
-- not
in NEUTRAL. See ªFour
-Wheel Drive
(Automatic Transfer Case)º in the Index.

4-58 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 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.