n1999 SLK 230 - short beep when turning key to start ?

[srdtvr]

Yesterday my old SLK started to do a short waring beeb when I turn key to start engine - no warning lights have appeared and everything is normal - any ideas please ?

[SLacKer]

Do you have a service due indicator showing spanners in the display?

[srdtvr]

all sorted - it was service indicator
now reset

Thanks