Thanks everyone for your interest and sympathy. It had only one bar left on the petrol indicator so, pretty low but not out yet. It had only got as far as the end of the courtyard so only about 20 metres before it went ping. We drove it around the block. It felt like it was just going on the petrol engine because there was a general lack of power. And also, the power steering seemed to be off. It felt like something I might have driven in the '70s (had I been driving in the '70s ).

The Prius is a year 2000, has done about 90 000.

I haven't tried the turn off turn on x 3 thing.

When I looked at the engine, I noticed a black box located on the left hand side of the hybrid metal engine. The box has what looks like fuses pushed in to it. There were 3 'fuses' and one seemed to be gone. Do you think this has anything to do with it?