Agree with others, but have your pads, calipers, rotors and [B]brake fluid been checked to c if they are to specs???? No good fiddling with the ABS's CU if these items are not up to the job.

If you read the manual, u can c that it is normal and acceptable for some 'shudder' to occur under the 'pick up speed' of the ABS's CU (Control unit), it will appear to come from the front as thats whats happening. The pads are making/breaking contact with the rotors at this speed and the CU is not yet engagued. Usually not up untill about 10Kph.

If you r having shuddering or chattering problems @ speed , best check the calipers, and all above, as well as worn/unservicable steering/chassis components

Have fun, keep in touch,
Graham