Technical 30 mph sign on dash?

[min200]

I have a 30 mph sign thats just appeared on my dash and this has replaced the mpg display, it has what appears to be an ariel sign next to it.

Any ideas what this is and how I get the mpg display back?

 

[madham]

On the end of the washer/wiper stalk is a button, if you press this it will scroll through the trip computer menu.
Hold the button in for a few seconds to reset

 

[Most Easterly Pandas]

On the end of the washer/wiper stalk is a button, if you press this it will scroll through the trip computer menu.
Hold the button in for a few seconds to reset

What does it mean though

 

[madham]

30 mph sign is probably average speed .
if you scroll through menu using the button on wiper stalk it gives you running mpg, average mpg, miles till fuel runs out, date etc.
all in the handbook, if you have one.

 

[min200]

Thanks everyone!