Environment Error: μC2 supply voltage below minimum

What does 4 mean?

When LED Diag 1 is off and LED Diag 2 flashes with code 4 (400ms ON / 400ms OFF), it indicates that the internal supply voltage for microcontroller μC2 has fallen below its minimum permissible value. This environment error can lead to unreliable operation or unexpected behavior of the TwinSAFE component due to insufficient power for μC2, potentially impacting safety integrity.