Hummer 2007 H3 - Manual (Page 305)

Turn Signals When Towing a Trailer
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.
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
under heavy loads and/or hilly conditions.
If you have a manual transmission and you
are towing a trailer, it is better not to use the
highest gear.
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.
For manual transmissions, let the engine run
while parked, preferably on level ground, with the
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 338.
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