That's the engine oil quality light. It means you need an oil change.
Usually down to the regens not being completed properly.
Taken from the manual
Engine oil life monitor
illuminates yellow.
When the engine is started, C illuminates briefly. If it does not illuminate, seek the assistance of a workshop.
The engine oil life monitor lets you know when to change the oil. Control indicator C illuminates to indicate that engine oil life has been diminished and the oil needs changing.
Based on driving conditions, the interval at which an oil change will be indicated can vary considerably.
Change oil within 600 miles. Engine power may be decreased.
Once the engine oil has been changed 3 147, the engine oil life monitor needs to be reset. Seek the assistance of a workshop.Edited by: Grumps