Why does it show that there is no oil pressure and stop the engine in Volvo v70?

You must change the oil and filter. ASAP.

low oil pressure caused by sludge, mine was found in the Oil Filter, else

oil filter is clogged. Oil may be dirty , even at 3000 miles since last change.

I changed mine and the warnings have been off for a week.

Did not understand the warning, so towed the car home.

change the oil and filter , its much cheaper than a tow home.

so far so good.