I went a little bit deeper into the maintenance staff. If VEH PARAM OVERLIMIT shows up in the flight report after shut down, you should switch the CPDS into maintenance mode, select FAILURES and then the approbiate FlightNr ( normaly the last one ) with the +/- Buttons. Push ENTER and you get numbers of failures for the CAD and the VEMD. Select the one with at least 1 failure, press ENTER and you get the Failure Diagnosis. The first line shows the time of the occurence and below the respective failure code. There are some more than 100 different codes in the technical manuals ( SDS System Description Section 31-65-00-9 ).
One common failurecode is 109R, which indicates a failed selftest of the MMI, but if the MMI is indicating normal, this failure could be ignored. Its caused by the selftests ( During startup of the CPDS ) of the two VEMD Lines and when the analysis of Line 1 finishes earlier than the analysis of Line 2, the VEMD deactivates the results of line 2 and the errorcode 109R may be stored in the system.
skadi