GMC Jimmy 2004 - Driving on Grades; Parking on Hills

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.
If you have an automatic transmission, you can tow in
DRIVE (D). You may want to shift the transmission to
THIRD (3) or, if necessary, a lower gear selection if the
transmission shifts too often (e.g., under heavy loads
and/or hilly conditions). Or, 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 ‘‘Tow/Haul Mode’’
earlier in this section and ‘‘Tow/Haul Mode’’ under
Automatic Transmission Operation on page 2-25.
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 Engine Overheating on
page 5-28.
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.
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