Synch SOAP Receiver - Fault message - wrong response branch used

I implemented at SAP PI 7.50 a synchron integrated configuration from ERP Proxy via SOAP Receiver and back.

I can send the request and get back a response successfully. But when a fault message is sent back for the partner, this messages uses the response branch and not the fault branch at the operation mapping.

How decides the SOAP process/Operation Mapping if the response or the fault branch is used? Is it by means of the message content?

At the SOAP receiver I activated the parameter "do not use SOAP envelope", because if it is not activated, I don't get the whole fault message with SOAP envelope. I removed this envelope for the response message in the first mapping step.

I created an xsd analog to the partner fault message:

This is the response of the operation mapping

And this the fault

Thanks for all support and tipps

Sandra