The 159 1.9jtdm has started saying 'have engine checked'. The familiar
yellow engine light stays on too. The 156 always did this and I learned to
ignore it!

Car is running fine, no splutters, no bad noises, no smells, fuel
consumption normal. Its done 3-4k miles in the last month or so, but nowhere
near service time.

Anyone experience of this model/engine? Is it crying wolf, or should I
actually be concerned?

Cheers,
GT