Toyota 2003 Celica Owner's Manual page 84

If the indicator or buzzer comes on...
(h)
or
(i)
(j)
(k)
(l)
Key reminder buzzer
(m)
Light reminder buzzer
84
'03MY CELICA U (L/O 0208)
Take vehicle to Toyota dealer.
If the brake system warning light is also on, stop immediately and contact Toyota
dealer.
Close both side doors and back door.
Take vehicle to Toyota dealer immediately.
Stop and check.
Remove key.
Turn off lights.
2003 CELICA from Aug. '02 Prod. (OM20809U)
Do this.