DS5 PDF

[terry king]

Hi, I purchased a DS5 DSSPORT AUTO 2014 in May, Went on Holiday in July, and while on my holiday the orange engine management light came on saying there was an engine fault, I had it checked out at a garage and they said it was showing it was the PDF but the computer was saying it was ok so they reset it and sent me on my way, 40 miles down the road and it came back on! I'm home and took it to my regular garage he said the PDF was new and telling him it wasn't an issue! he reset it but after 10 miles it was back on again, he suggested I take it to Citroen so i did , they checked it out and reset it again, and after 10/15 miles it was back on!! took it back and they said it could be the sensor so replaced it ( but would not guarantee it would solve it ) and it didn't back on again!! now by this time it had cost me several hundred pounds and getting nowhere, Citroen then said well the new DPF wasn't a Citroen part and this could be the issue! and they suggested replacing this the cost of this would be £2500 ( but they would not guarantee this would solve the issue!!! so at this time I am completely confused and depressed where on earth do I go and do, love the car but it's frustrating!!!!!!

Terry

[GiveMeABreak]

Several possibilities:

1) Is the DPF actually new? and if so was it an aftermarket part?
2) If the Engine ECU is told the DPF is new when it isn't, and the filter is blocking up, the differential pressure sensors (that measure the gas pressure before and after the particle filter) will be telling the engine ECU the filter is blocking and flagging the warning.

So either the DPF is not regenerating and the pressures are high, or there is a problem with the filter itself. The DPF differential pressure sensors should be able to be tested by Citroen to make sure they are working using the live data to measure the pressure levels reported. That should tell them if the filter is blocked or not or whether the sensors are giving wild readings. They may also attempt a forced regeneration if the engine ECU will permit this.

If the filter has gone past the point of being 70+% blocked, the regeneration may not be possible as the filter is too far blocked and will not be able to regenerate.

Either way it needs looking at and I would first be asking Citroen to check the pressure sensors to see if they are operating correctly. If they are, then I suspect either an incorrect DPF has been fitted, or an extremely cheap one that isn't working

[PaulC5]

If it turns out the pressure sensors are working correctly and it is not the DPF, could it be a blockage/restriction elsewhere in the exhaust ?

[terry king]

Hi, Citroen replaced the differential pressure sensor And reprogramming was done , but they did say this may or may not work, but the Dpf was new but aftermarket!! (Fitted prior to me buying it) The bit I'm finding hard is me paying another £2500 pounds to replace the dpf to see if that works !! With no guarantee it will!!

[GiveMeABreak]

You can get them a lot cheaper than that - but that doesn't mean it has to be a real cheap version.

What fault codes are showing - if you paid for a diagnostic, you should be entitled to the printout or the report detailing the faults.

[terry king]

First one said fault codes p2463 p246c p2 partical filter faults blocked, but the pf was clean on checking it ? I assume I could get them cheaper but this was Citroen!! My worry is if I replace that on the off chance it works what next ??

[GiveMeABreak]

Ok, so this is where the fault codes really help.

There is a technical issue for this vehicle where fault codes P2463, P246C or P24A4 are present with a warning lamp with or without loss of power.

The service action is:

• Erase the fault codes.
• Accelerate with no load to an engine speed of 3000 rpm for 3 minutes.

So that may be a cheap fix if it works.

This is normally for new vehicles with less than 100 Kms on the clock - but may be relevant if you have had the DPF changed. It's basically a matter of cleaning the DPF out and this may solve it.

[NotAnInterestingName]

Has anyone done a DPF regen, or do they just keep clearing the messages?

[GiveMeABreak]

A forced regeneration should only be a last resort, due to the fact that the vehicle is stationary and with lack of cooling, this puts extreme heat on engine components.

Under normal conditions with reasonable journeys that are not of consistently short distances the assisted regeneration does the job as needed. The 'Risk of Filter Clogging' message only appears after failed attempts at regeneration or when the DPF pressure sensors are reading a blocked filter. This is normally combatted with a drive of reasonable distance and duration to allow exhaust temperature to get to that required for successful regeneration AND for the cycle to complete before the engine is switched off.

Clearing the messages won't do anything if the problem exists.

[NotAnInterestingName]

I did a forced regen after getting the Adblue system fixed, which was recommended by the garage. The Adblue and DPF systems are separate functionally but in reality are different ends of the same unit, so are related. Just wondering if back-pressure is causing misleading messages. Presumably if it happened on holiday then this was during a long journey so it would have had loads of chance to sort itself out.

I used the PSA software via a laptop. Was initially alarmed when the engine started revving up under control of the software, was then further worried by the pretty substantial clouds coming out. But all completed successfully, nothing melted and it's been fine for a year since. But yes, I'm sure there are risks. The exhaust exit is within a plastic surround on the DS5 as part of the bumper so this at least could be an issue due to lack of airflow.

[GiveMeABreak]

They are not related at all in that they have no interaction with each other and neither do the control systems.

So this is a one assembly module that contains the DeNox Catalytic Converter and then the DPF.
The particle filter pressure sensors are mounted upstream (before the DPF part) and then downstream (after the DPF filter).

The Adblue injector is way before there and once the adblue is sprayed in, it turns to ammonia from the heat and this reacts with the nitrogen oxides and the oxygen to convert it to water.

As you can see from my picture circled in red: 'b' is the upstream DPF sensor which would be just before the DPF (4) inside the assembly; 'a' is the downstream DPF sensor; the yellow circle is where the Adblue injector is located (though not physically shown on this diagram as this is for the DPF part of the system). (5) is is just where the differential pressure sensor is mounted are and where the pipes 'a' & 'b' shown connect back to, but the measurements are taken at 'a' & 'b'.

[NotAnInterestingName]

As I said, functionally separate but in fact the same unit.

Mine had been massively over-dispensing Adblue due to a faulty injector and/or sensor, the exhaust surround in the back bumper was covered in a thick crust of white crystals. So replaced the sensor and injector, but the worry was that the DPF would be in a similar sort of mess. Seemed like a sensible precaution, no ill effects and all working wonderfully since.

[GiveMeABreak]

Sounds like the Adblue injector was over-dosing, and that may be a s a result of the NOx sensor at the rear going faulty, in effect saying the NOx is too high - inject more Adblue.

Hard to say what effect this would have on the DPF internals, but I suspect once crystallised, the crystals don't burn easily - if they are still in the exhaust and the same when the injector fails and crystallisation occurs there, despite the heat.

[NotAnInterestingName]

I never did diagnose the issue, it would have cost more in labour and taken longer to replace the sensor then the injector so I just bought both then asked the garage to replace them. Both are subject to extreme temperatures so this seemed like a sensible way forward.

I thought the same, wondered whether crystals would burn or not. But I did it, lots of smoke came out and all has been well for a year since, no more snow on the back bumper either.