Cadillac 2001 Catera Owner's Manual page 149

If it doesn't come on, be sure to have it fixed so it will
be there to warn you if something goes wrong.
When the light comes on and stays on, it means that
oil isn't flowing through the engine properly. You could
be low on oil and you might have some other
system problem.
CAUTION:
Don't keep driving if the oil pressure is low.
If you do, your engine can become so hot that it
catches fire. You or others could be burned.
Check your oil as soon as possible and have your
vehicle serviced.
2-82
The oil light goes on when
you turn the key to ON or
START. It goes off once
you start the engine.
That's a check to be sure
the light works.
NOTICE:
Damage to your engine from neglected oil
problems can be costly and is not covered by
your warranty.
Check Oil Light
If the light comes on while starting and stays on for
about one minute or comes on while driving, the engine
oil level should be checked. Prior to checking the oil
level, be sure your vehicle has been shut off for several
minutes and is on a level surface. Check the oil level
and bring it to the proper level. See "Engine Oil" in
the Index.
This light will come on for
a few seconds when the
ignition is turned on. If the
light doesn't come on, have
it repaired.