"Harry Bloomfield"; "Esq." wrote in message
...
tim... used his keyboard to write :
mine just indicated it was a choice of sensors

the garage said, we can guess and if we guess right first time it will
cost you 80 quid

if we guess right last time, it will be 5-600

The diagnostics always require some skill in interpretation.

Not always, they often get it right.

Given clues by the diagnostics, you can usually get the test gear out to
see what is happening.

Or decide if the sensor etc that has been claimed to
have failed would produce the symptoms you see.