So if removing and re-fitting the yellow plug doesn't work, but the display is showing information, I'd say the remote stalk may be knackered.
The two means of fixing it that I can think of are:
Undo the cowling around the steering column, remove the remote stalk, and either:
1) Disassemble it and try repairing it
2) Replace it with one bought off the scrappy's or eBay
Also, if you can confirm it has worked before, you could try removing and re-fitting the connector at the stalk's end before proceeding with the above.
(If there are two, just do both. One goes to the radio, the other goes up to the display.)