2006my v70 D5 Euro 4 engine system fault code 042

[miraboss]

My v70 exhibits message "engine system service required". when I check using the ignition key turn & holding down the mileage reset button I get the code 042.
Outwardly the car sounds, feels, drives as normal.
does anyone recognise this fault code on this Euro 4 D5 car with particulate filter.
What do I need to do to service the engine system so that the message and risk will be removed?
Miraboss.

[vorbosh]

The cheap way is to disconnect the battery and reconnect it.

This worked for me.