No 'kick down' in sport mode

Have developed a strange problem - no kick down in sport mode - the red indicator light has also gone very dim. the dash is not showing a fault and the S or sport is indicated on the dash when it's selected.

Any thoughts or ideas as to what may have occoured welcome.

maybe gearbox ECU??

Right now to reply to my own thread - the sport mode now works and the random error messages have ceased.

Why? - I changed the battery after the starting becam sluggish. So just to confirm what other various threads say many issues seem to be related to low battery power including in my case sport not working, gearbox overheat/ bearbox fault / altenator failure etc...

Changing the batter required trial and error but got there in the end!