Lexus 2003 LS Owner's Manual page 454

Item
Voice The system does not
recogni- respond when I start
tion to talk.
The voice recognition
function does not
work when I press
the HOOK key.
Others The system does not
work at all.
Section 6
Symptom*
Troubleshooting
Solution
Use voice recognition
under quiet conditions: If
the noise level in vehicle
is too high, the voice
may be unrecognizable.
Check the setting of
voice recognition: If it is
set to OFF, set to ON
(see p. 51).
Make sure you are us-
ing an approved phone.
(Consult your Lexus
dealer for approved
phone.)