I have had this problem with a 3.2 diesel A4 AllRoad, in spite of filling it right up. Taken it to an independent VAG specialist who says that I need a new sensor. However, the new sensor would need to work with a new pump and they don't make the integrated pump and tank any more so I would have to renew the whole system: parts, fitted, programmed = £2500. Parts not currently available. Or... I could disconnect it and use the car and decided on this. Was rung back to say that it now gives 310bhp as opposed to the original 218! Cost around £300. Result. Someone suggested that this was the state of the car industry: no one is selling new cars because of the confusion over electric cars so they need to make money on spares. They therefore update spares so a whole unit has to be fitted, rather than what you need. That's how they're making their money.
