GMC 1996 Sonoma Owner's Manual page 207

Engine Fa-- N
-
Ise
e Goes Flat
This vehicle has a clutched engine cooling fan. When
the clutch is engaged, the fan spins faster to provide
more air to cool the engine. In most every day driving
conditions the clutch is not engaged. This improves fuel
economy and reduces fan noise. Under heavy vehicle
loading, trailer towing and/or high outside temperatures,
the fan speed increases when the clutch engages. So
you may hear an increase in fan noise. This is normal
and should not be mistaken as the transmission
slipping or making extra shifts. It is merely the
cooling system functioning properly. The fan will slow
down when additional cooling is not required and the
clutch disengages.
You may also hear this fan noise when you start the
engine. It will go away as the fan clutch disengages.
It's unusual for a tire to "blow out" while you're driving,
especially if you maintain your tires properly. If air goes
out of a tire, it's much more likely to leak out slowly.
But if you should ever have a "blowout," here are a few
tips about what to expect and what to do:
If a front tire fails, the flat tire will create a drag that
pulls the vehicle toward that side. Take your foot off the
accelerator pedal and grip the steering wheel firmly.
Steer to maintain lane position, and then gently brake to
a stop well out of the traffic lane.
A rear blowout, particularly on a curve, acts much like a
skid and may require the same correction you'd use in a
skid. In any rear blowout, remove your foot from the
accelerator pedal. Get the vehicle under control by
steering the way you want the vehicle to go. It may be
very bumpy and noisy, but you can still steer. Gently
brake
to
a stop -- well off the road
if
possible.
If a tire goes flat, the next part shows how to use your
jacking equipment to change a flat tire safely.