Chevrolet 2007 Express 2007 Express Owner's Manual page 280

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.
280
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.
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, see Engine Overheating
on page 311.