Cadillac 2001 Catera Owner's Manual page 95

Upshifting and downshifting of the transmission is
automatically modified to prevent undesired shifting
when your vehicle is towing a trailer or when you
are driving in hilly or mountainous terrain.
This is also normal.
Sport Mode Button
2-28
For a firmer shift and
increased performance, you
may choose the sport mode.
This button lets you change
from a normal driving mode
to a sport driving mode.
It is located on the shift
lever handle.
Press the "S" button once to select the sport feature.
Press it again to return to the normal driving mode.
When you start the engine, your vehicle will be in
normal mode. For general driving conditions, use the
normal mode. It will remain in normal unless you select
the sport feature.
If this light begins flashing while you are driving,
there may be a fault in the automatic transmission.
Have your vehicle serviced.
This light on the instrument
panel cluster will come
on when the sport mode
is selected.