Affected unit must not enter service.
Check power supply BCU MCB
(+357/B).
Attempt to reset.
If unable to reset, isolate Brake Unit
Isolation Cock (B4) on PTOS
(inside saloon under seat).
Press and hold Brake Release Valve
(B5) until all air is ventilated.
If possible, transfer passengers from
affected vehicle.
Report defect to Signaller and refer to
degraded mode instructions
All defects must be recorded.