Xantia amber engine light and no start question/ideas

[Tommy1]

Hi all and thanks for your help will have a look see who can help me out.had a mobile diagnostic out he said it was showing no faults he reset service light It wasnt a lexia diagnostic he left I drove for 5mins service light back on same problem just £45 worse off but suns shining a big thanks again for your welcomes and responses

[ihatecars]

Yeh that's what we found when we hooked up the Lexia. The results suggested everything was good, all sensors correct and working. But not so 2 hours later. The first crucial suggestion was, having the Lexia connected when the fault showed, which makes perfect technical sense but perhaps a little awkward in reality (my Lexia-owner had gone by now). I wonder, when you ask your local Lexia owner to pop over, is it possible then to drive the car around with the Lexia connected and take readings "live"? Obviously, one person drives and the Lexia owner rides shotgun with laptop etc.
I don't own a Lexia so don't know but, I wonder if it can act as an oscilloscope on sensors, as seeing the output from my wonky crank-position-sensor might have helped if we had known to look at it.

Member, Mandrake gave a good technical explanation that made perfect sense which linked everything together.