You are using SOAP adapter and when service returns SOAP Fault, you want to catch, use, or log the exception payload.
This method explained in a blog post in SAP Community.
The exception payload will be included in message property CamelExceptionCaught and has the type org.apache.cxf.binding.soap.SoapFault.
To see all available methods in this class see the Javadoc
Groovy IDE notice
You can't test this example with GroovyIDE at the moment.