ABS – Repair

Good morning to the gentlemen, I had my Up! for inspection in November and even before the warranty had expired, I addressed two defects that were to be repaired. Outer bearings clacked and a high frequency whistle when pressing the brake As far as the acquisition of the costs of VW to the AH was confirmed and the repair was started at the beginning of December. The outer bearings were also done immediately. However, the whistle turned out to be a faulty ABS system, which was also exchanged rde, but since now 6 weeks can not be connected to the engine control unit, because there are no correct codes from VW. Has someone experienced this before? Generally I have no problem with the duration of the repair, because I have a free rental car, but I would like to have my car back again.