Trafic II – Where does the ABS control unit sit?

Hi together, I try to fix the Trafic (II from 2006 with 2.0 DCI90) from a friend where the speedometer has failed and a speed limit to about 2800rpm. There is no error memory entry over a sensor failure or ABS fault (also no light). In the net I found similar cases where the cable from ABS to the speedometer seems to have a defect – I would like to check that. Where is the ABS ECU in a Trafic 2? I have something from Unterbod or read at the “battery flap”?!? Did you happen to have jmd info where the cable could go from ABS to Tacho in about a long time? Thank you! The info would help me very much in repairing