I may be wrong, but if an wheel sensor is out it will light the ABS lamp as well, so 3 Amigos.
I think 2 amigos is more likely the brake switch.
Reading the diagnostic codes will give the answer though. I think Halfords in the UK will read codes, dunno if they charge for it. I take mine down to my local LR indie garage when I need the codes read and cover their palms with a few tokens.