Siemens CPU 31xC / CPU 31x Error Codes: List of 5 Codes and Their Meaning

This is the list of error codes the Siemens manual gives for the CPU 31xC / CPU 31x Siemens CPU 31xC / CPU 31x. Find your code below and open it for what the manual says about its causes and what to do.

Error codes from p. 54

Code	What it means	Page
`SF`	Hardware fault or software error	p. 54
`BF1`	Bus error at the first interface (X1)	p. 54
`BF2`	Bus error at the second interface (X2)	p. 54
`BF3`	Bus error at the third interface (X3)	p. 54
`MAINT`	Maintenance demanded	p. 54

Codes and descriptions are taken from the manufacturer’s manual; page numbers link to the PDF. ManualLib is not affiliated with Siemens. Found a mistake? Report an error.