Eolys additive pump running after switch off ?

[tmead]

Does anyone else with a 2.2 HDi hear the additive pump running after switching off the car ? When I switch off I get a buzzing noise from down by the nearside rear wheel on my C5 (yes - not a pug I know, but please help anyway!). I'm not sure its the additive pump, but can't think what else it is.

Zooankski has helped me out with reading the codes, and the car is not sensing the filler cap correctly, so I'm surprised if the additive pump is doing anything ! Citroen parts are more expensive than Pug, as the sensor is quoted at 50 quid, non-refundable once ordered, and the guy wasn't even sure he had found the right part !

I've taken off one of the two connectors on the end of the wire (only just found out from Citroen that they believe there are two connectors above the LP fuel pump on the C5), and there is a change in resistance between the terminals I measured from around 100 ohms to almost open circuit, but if it's a hall effect sensor I'm not sure that a simple resistance check is enough. Frustratingly, a hall effect sensor is in itself not an expensive device, and I could buy an industrial one for around a fiver ! It's tempting I can tell you.

Tim