I would guess at this being the priming pump in the fuel tank.
When you turn the ignition on, you should hear a short buzz of about 5
seconds, this is the fuel system priming up ready.
If this pump does not prime the car will nor start.
The failure of the priming pump is a common problem for all of the HDI
engined cars, try turning on the ignition then laying down under the
car and give the bottem of the fuel tank a good hard slap, sometimes
this alone will get it to prime, but usually only to fail again next
time!!
Regards
Slim
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