TC reported TIMS showed APS comms fault& no line voltage at car 1569. TC tried to aux on- unable toclear fault. SM(KRJ) checked & confirmed no converter fault & line voltage- ok at car 1569. Subsequently, TC reported T  ~~~~~ TC reported TIMS showed APS comms fault     Checked Tims and found TRC4-2 of 1569 software error,replaced satis.NO APS comms fault.Swapped 1569 APS controller to 1570.Monitored for 1 hour,fault transfered.Replaced faulty APS controller at 1570 and APS fault recurred.To raise OPS-20 for APS controller c/o whrn spare is available. APS control Unit (1570) Old s/n: 113RC000-4H New s/n: 574R4-213 TRC4 (1569) Old s/n: CY51659PZ New s/n:   Done by Pravin/Joshua  04/03/22 To replace 1570 APS Control Unit Replaced APS control unit at #1570 due to spare unit faulty(FC-419)APS power and no power test ok.Monitor and depot limited movement ok. APS Control,,Unit- New s/n: 320RX104-1H Old s/n: 574R4-2H Done by Saini/Asruddin.  7/3/22