warning lights

hi phil here---the first time i went off road in my landy this yellow light came on marked TC i panicked as never seen this before, read owners manuel and it was my tracktion control light telling me that the tracktion control was being activated as i had lost tracktion as i found out when i realised that my back drivers side wheel was in the air hope this is of help.

I have an issue with my HDC amber warning light beining continually on. I have checked the yellow switch and all seems ok. It has been mentioned to check the ABS sensor. Does anybody have experience of this sensor failing and how to get to it?