C8 - DPF replacement

[masterofinsanity]

HI, ive replaced the DPF on my citoren C8 tonight, reset the additive ECU, anything else i need to do, the label on the new DPF suggested i need to regenerate it but surely the car will do that now ive taken it up the dual track a few times? car seems to run smoother.

Lexia says the DPF has gone from regenerated on the old DPF to intermediate stage on the new DPF
any ideas what it should be?
thanks in advance

[RichardW]

Can't imagine there's any point regenerating a new DPF - there won't be any soot to regenerate.... I'd just leave it, and check that it has regenerated in 300 miles or so.

[Lighty]

Main thing is to decide why it needed replacing in the first place,the new ones (pattern) seem to block much faster than the oe ones. This may. Be due to people never understanding why the problem occurred.
Changed one today that had been on 3 weeks, turned out that the car had not been boosting correctly, and 3 weeks of limp home mode blocked the replacement.
So long as the fluid tank has some in, and is working, you should be ok if full power is available etc.

[wheeler]

Agreed, you don't regenerate a new filter as it is already regenerated with it being brand new.
As for the replacement reasons really depends on the mileage, the DPF/FAP is due to be replaced/exchanged around the 80k mark if everything is operating correctly. The Eolys additive used to assist regeneration doesn't actually burn off but stays trapped in the filter, if everything is operating correctly this is what eventually blocks the filter.
Did you also top up the fluid, if the tank runs empty then the DPF will block up with soot very quickly. To get the best operation out of it you need to fill the fuel tank to full & run it down, if you normally add only small amounts of diesel the additive tank will empty quite quickly as well.

[masterofinsanity]

thanks guys for your guidance, I haven't topped up the fluid as Lexia says it hasn't reached the minimum level and when we sent it back to the dealer he said it was fine.we've only had the car a few months and its been a nightmare hence me buying a lexia to try and sort it.It had a new DPF back in 2012 but Citroen said it was blocked, I had it regenerated but still getting the loss of power and limp mode.The filler cap sensor has not been working for god knows how long which I have replaced the loom but still not working so I need to find the cause of that, short to earth somewhere, or put a manual switch in , so that's the reason for the additive not keeping the filter unblocked, anyway I wasn't taking any chances so put a new DPF on.

......and ive tested the additive pump and its working fine.
thanks again

[dnsey]

If you can't sort the filler cap problem very soon, I'd be inclined to add a very small amount (I haven't calculated it) of Eolys to each tank of fuel, or, as Lighty and Wheeler have said, your new filter will quickly block up again.

[Lighty]

It is imperative that you check your dpf differential pressures, they are I. The parameters section of the engine ECU under particulate filter. They should ideally be zero at idle and about25/30 mb when Erving at about 3000 rpm, often the sensor gets damaged when driven with a blocked filter. If this is the case it will permanently read 117 mb or zero.
What fault codes are you getting with it in limp mode?, or is it ok now.

[masterofinsanity]

If you can't sort the filler cap problem very soon, I'd be inclined to add a very small amount (I haven't calculated it) of Eolys to each tank of fuel, or, as Lighty and Wheeler have said, your new filter will quickly block up again.

if i can't find this short circuit then i'm gonna have to add a manual switch to tell the ecu ive removed the filler cap and replaced it.

It is imperative that you check your dpf differential pressures, they are I. The parameters section of the engine ECU under particulate filter. They should ideally be zero at idle and about25/30 mb when Erving at about 3000 rpm, often the sensor gets damaged when driven with a blocked filter. If this is the case it will permanently read 117 mb or zero.
What fault codes are you getting with it in limp mode?, or is it ok now.

i checked the pressures before i replaced the DPF and then i was getting 12-15mb which really didnt convince me the dpf was blocked but i didnt realise you had to read it about 3000rpm til afterwards, havent taken a reading with the new dpf on, i did the 10 litre of fuel after replacing the dpf and with my manual filler cap off/on bodge i can see the additive level has changed.

Just need to find this short to earth!

[Lighty]

The harness plug is quite vulnerable

[masterofinsanity]

The harness plug is quite vulnerable

do you mean the plug that the filler harness plugs into? i did wonder if it could be that, its strange that theres a short to earth but if i disconnect the filler loom it says cap present, if i connect it it says cap absent so the signal must be getting there but if i have the loom connected and put the filler cap on it does nothing ?

i might cut the plug off and see if the short disappears

[dnsey]

In 'Lexia speak', short to earth shouldn't be taken too literally - better to interpret it as an undefined electrical fault.
I don't remamber whether the cap is sensed by a reed switch or a Hall-effect device, but that's where I'd start by looking.

[masterofinsanity]

i put a new filler cap sensor on but the ecu doesnt detect the filler cap although both magnets are present, yet if i disconnect the sensor the ecu detects a change ? figure that out cos its baffling me! and lexia says theres a short to earth, i though a continuity check between both pins on the connector would give continuity but nothing, and each pin to earth gives no continuity? scratching my head!