ML270cdi 2003 in that abs / bas/esp lights on.

  mercedes/m-class/1998-2005

I have issue with ML270cdi 2003 in that abs / bas/esp lights on.
The abs/bas is on all the time and the esp only goes out for 3 seconds when starting engine
Have replaced brake light switch and one wheel sensor that the cdp diagnostic found
Also, test motor runs in ABS unit swapped relays etc.
However, cannot get ABS to respond to the diagnostic at all ?
I am assuming ABS module has gone U/S any guidance ?

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