Chevrolet EXPRESS - 2011 Manual page 287

Wait at least 30 minutes with the
engine Off, before checking the
transmission fluid level if the vehicle
has been driven:
In hot weather, when outside
temperatures are above
32°C (90°F).
The vehicle is heavily loaded.
At high speed for quite a while
in hot weather.
In heavy traffic and hot weather.
While pulling a trailer.
After driving under these conditions,
a hot check can be performed. The
fluid should be Hot, which is 71°C to
93°C (160°F to 200°F).
A cold fluid level check can be
performed after the vehicle has
been sitting for eight hours or more
with the engine off, but this is used
only as a reference. Let the engine
run at idle for five minutes if outside
temperatures is between 15°C to
32°C (60°F to 90°F). Should the
fluid level be low during this cold
check, the fluid must be checked
Warm or Hot before adding fluid.
If the outside temperature is colder
than 15°C (60°F) or hotter than
32°C (90°F), a cold check cannot
be performed.
A warm fluid level check can be
performed by driving the vehicle
under lightly loaded conditions and
outside temperatures between
10°C to 27°C (50°F to 80°F).
The vehicle should be driven
for at least 24 km (15 mi) before
performing a warm check. Checking
the fluid Warm or Hot will give a
more accurate reading of the fluid
level than a cold check.
Because the vehicle is equipped
with a high-efficiency air-to-oil
cooler, the transmission fluid
temperature may not reach the
required Hot fluid level checking
temperature under normal
lightly loaded driving vehicle
conditions.