A brake control unit comprising a primary control branch , a backup control branch , diagnostic utilities and mode control utilities , the primary control branch having a primary inverter and a primary control module to control operation of the primary inverter; the backup control branch having a backup inverter and a backup control module to control operation of the backup inverter, wherein the diagnostic utilities are configured to determine an integrity status (S INT ) of both control branches ; wherein the mode control utilities are configured to select, in accordance with said determination of the integrity status (S INT ), an operational mode of the brake control unit from a plurality of potential operational modes (M0-M4), comprising at least a normal operational mode (M1) and a degraded operational mode (M2,M3), wherein respectively the primary control branch and the backup control branch are configured to generate a brake motor drive signal (D 10 , D 20 ) with their respective inverter being controlled by their respective control module in response to an external brake control signal (I B ), wherein the primary control module includes at least first and second mutually cooperating primary control components with respective first and second diagnostic units that are part of said diagnostic utilities in that the first diagnostic unit of the first primary control component is configured to diagnose (QA) an integrity of the second primary control component , and the second diagnostic unit of the second primary control component is configured to diagnose (QA) an integrity of the first primary control component , characterized in that the diagnostic utilities further comprise a third diagnostic unit configured to diagnose an integrity status of the backup control branch by verifying a response signal (S R ) of the backup control branch in response to a test signal (S T ). the primary control branch having a primary inverter and a primary control module to control operation of the primary inverter; the backup control branch having a backup inverter and a backup control module to control operation of the backup inverter, wherein the diagnostic utilities are configured to determine an integrity status (S INT ) of both control branches ; wherein the mode control utilities are configured to select, in accordance with said determination of the integrity status (S INT ), an operational mode of the brake control unit from a plurality of potential operational modes (M0-M4), comprising at least a normal operational mode (M1) and a degraded operational mode (M2,M3), wherein respectively the primary control branch and the backup control branch are configured to generate a brake motor drive signal (D 10 , D 20 ) with their respective inverter being controlled by their respective control module in response to an external brake control signal (I B ), wherein the primary control module includes at least first and second mutually cooperating primary control components with respective first and second diagnostic units that are part of said diagnostic utilities in that the first diagnostic unit of the first primary control component is configured to diagnose (QA) an integrity of the second primary control component , and the second diagnostic unit of the second primary control component is configured to diagnose (QA) an integrity of the first primary control component , <EOS>