Diamante Sei ABS problem

[triode]

Hi

I have a 99 diamante which I have had since new.

Earlier in the year a couple of times the TCL light would flash for a few minutes then go back to normal.

Now I have the park brake/TCL and ABS lights on after about 2/3 minutes after starting in the morning, then they remain on all day.

WHen the lights are off, ABS performs normally, obviously it does not when on.

Have any of you come across this before? Is it a sensor failing, or is it the ABS unit itself. My local garage were spectacularly useless in trying to fix this.

If any of you can help, I would really appreciate it.

Kind regards

BIll