outside temperature display not showing

I've noticed my c3's display won't display the outside temperature but the hand book says that quickly pressing the right button should switch it form time to temp, any ideas?

Thank you for sharing the info about the C2 and C3 headrests compatibility.

I can confirm, with the 'ignition' on, that pressing the right button (its marked as a tick) does switch to temperature from time.

With the radio on, the display switches from frequency to temperature.

I have seen the display switch to temperature itself in the cold when I wanted to know the time

Thanks for the comment on the temp reading. Mine does not show it and the dealer said there needs to be a sensor underneath the passenger side mirror which to my untrained eye i can't see. I have tried searching for the factory spec of my 2005 C3 Desire but to no avail. It's a really small issue but i've always found the outside temp useful! If i press the right button it does nothing but the Citroen C3 handbook that came with the car clearly states that it does?

Oh well i guess i'm snookered! Thanks for the input.

A quick search suggests its the drivers side (OS) that has the sensor built in.

Just adding the sensor may only be part of the job as the ECU may need to be made aware of the new sensor to make use of it.