Mitsubishi Electric PAR-CT01MAU-SB Instruction Book page 75

Checking the error information
While no errors are occurring, page 2/2 of the error
information (refer to page 73) can be viewed from
the menu operation.
Select "Maintenance menu" from the Main menu, and
press the button.
SELECT
To display the error information screen, select "Error
information" from the Maintenance menu.
Errors cannot be reset.
75