Hi guys,
Toxic has placed a fine link which explains most of the features which can be switched on/off by (extended/OBD2) diagnose tools like VAG COM or the VAS5051/52 systems most of the SEAT dealers are using (at least in Germany).
Here is another, which I've posted several times before:
=>
http://de.openobd.org/index.htm
For me it has the most complete overview for VAG cars up to 2006/07, unfortunately only parts have been translated to English, still you can take a glance at the SEAT part within the German corner.
To all who are missing the seat belt signal: it can be easily turned on again by OBD2-coding ...
but looking at the starter's (hanxslf) malfunctions with multiple sounding features, I assume that the instrument controller might be affected, as the beep is produced electronically.
Another way to check: If your Altea model has the "tyre control monitor" (button in front of armrest) try to hold this for approx. 5 sec. to force a reset/restart for the monitoring.
If there is no acknowledgement sound either (you still should have noticed the corresponding LED being on for that time in the instruments panel), the "beeper" seems to be gone for good ...
greets ... Klaus