Power unit: I2C bus error occurred

What does F30903 mean?

This fault signifies a communication error on the I2C bus, typically with an EEPROM or an A/D converter within the power unit. The fault value (r0949) provides specific detail: 80000000 hex indicates an internal software error, while 00000001-0000FFFF hex points to a module fault. This can lead to incorrect readings, configuration issues, or unreliable operation. The risk is complete or partial failure of the affected module.