DPF for C8 2.2 (bonus Lexia question)

[MixerFistit]

I can't communicate with the DPF on this cheap C8 I picked up.

2.2 HDi. Does that mean it's likely.. errhum..
gone for a walk..?

There's no comms with the fuel cap switch either if that's a clue but it does think EOLYS is present.

According to a diagram I saw posted by Marc, it's a full CAN*, but if I select C8 CAN in diagbox, I have to manually put VIN and RPO in. If I select C8 it picks up VIN automatically. Also in C8 CAN it offers Diagbox but only picks up Ignition Ecu (Lexia picks up most sections fine once VIN/RPO put in)
Diagbox does let me calibrate the self leveling headlights so maybe diagbox is just for adjusting lamps on this model)
I don't have any cause to worry about a blocked dpf btw, I'm just poking around for faults - so far, they all seem to be electrical issues, Airbag comms, sunroof comms, boot lamp etc etc.
VF7**************[VIN obfuscated, can be read by forum staff]
*it has 4 ignition positions because I'm an idiot and didn't count the off position so partial CAN by the looks.

While I'm editing, I've looked underneath and both the dpf (shell at least) is there with its sensor pipes as is the eolys tank.
I do not have a Webasto though, theres a big gap where it should be. Unless the 6 seater version didn't have one..

[oldbill]

I have to take my grandkids home in a minute so I'll keep it short.
Yes definately gone walkabout!
You can turn Eolys off if you want or if its still dosing fill it up with diesel.
I never had much luck with Diagbox on my old C8 but Lexia did everything.
The shell will have internal hole.
The Webasto heaters would never even turn on at UK temparatures. there was lots of metal water pipes connecting them up which rotted and rusted away so most bit the dust.

Bill

[MixerFistit]

Cheers Bill, I wonder if I should make it disappear from lexia (the dpf and webasto too), that said, if it's all working it's probably best left alone. I just didn't want to be caught out 1000 miles down the road with a blocked dpf and stuck.
I've just fitted a new thermostat (not as easy as it should've been) so now realise I don't need the webasto anyway!
I had a bit of a look around lexia and couldn't see anywhere for DPF differential pressures just to confirm someone's accidentally poked a hole through it
It must be there somewhere, I'll have to go digging in parameters again.

[GiveMeABreak]

So lets stop all this talk of crippling the emissions systems - we don't condone it here and it's illegal, thanks

That said, this C8 shows as having the separate additive ECU, unlike later vehicles where the engine ECU controls the additive.

As such, it is well known that these control boxes can go toes up, especially when the time comes to reset them when the Eolys additive fluid is topped up. It was a big issue on the C5s too. It often necessitated a replacement of the control box when this operation was done. The issue was not being able to communicate with it to reset the additive counter. It may be possible that this is what has happened to yours too and why you are not getting any communication with it.

You have a CAN VAN Multiplexed assembly, so not full CAN with RPO of 10375

[wheeler]

Im a bit confused, what do you mean you cant communicate with the DPF?
Are you saying you cant communicate with the additive system?? If so how do you know there is no comms with the fuel cap switch?
If you did disable the Eolys & fill the tank with diesel you would soon know about it as the DPF would clog in no time as it wouldn't be able to regenerate properly.
The differential pressure will be under parameter measurements in the injection ECU menus, There will then be sub menus, cant remember exactly the description if its under exhaust system or de pollution.
As said above early additive system ECU's can be problematic, the normally work ok till the time comes to re set after refilling Then is just wont reset, out of all the ones i have replaced for this reason there has never been an issue with communication, it just wont reset the counters.

As for the Webasto, I dont think I've ever seen a UK diesel model without one.

[Rp0thejester]

ALL OFF YOU, STOP RIGHT NOW!!!!!! What the heck is the fuel cap switch got to do with anything!? I drive a C8 2.2 06 plate and ain't heard of that!! She will throw codes everywhere but fuel cap switch?? Ain't heard that one. If and ONLY if you've disconnected the positive from the battery and still get a code, deal with it.

[Rp0thejester]

Sorry that sounded aggressive, it wasn't meant to be. I feel so passionate about these cars that I don't want to see them become extinct, my apologies

[wheeler]

Early DPF equipped PSA cars have a sensor that detects when the fuel cap is removed so it knows when you are adding fuel so it can calculate how much Eolys to inject. If its not working it may not inject additive or inject the right amount. Next tome you remove your fuel cap look on the side & you will see a couple of magnets on the cap, these line up wiith a magnetic reed switch in the filler neck.

[Rp0thejester]

I definitely don't have magnets on my filler cover or the filler cap, was this put on pre 06 C8s?

[Rp0thejester]

As for the DPF on 2.2s just a bit of DPF Cleaner will sort it. She seems to sort herself out somehow.!!

[wheeler]

I definitely don't have magnets on my filler cover or the filler cap, was this put on pre 06 C8s?

Have another look, not immediately obvious at first. Early ones had it, some more modern models still have the caps with magnets even though the sensors were phased out

[Rp0thejester]

I can guarantee mine doesn't have that. Could it be because I have the display screen or a swapped fuel cap?

[MixerFistit]

Im a bit confused, what do you mean you cant communicate with the DPF?

--When accessing the static regen it is unable to progress - I can't remember the exact error message but it was along the lines of not communicating rather than not ready due to temps etc. I know it's not recommended to just do it, but I was trying to preempt any potential serious issues that may have forced a sale by previous owners. I looked in 2 locations, the personal maintenance section (that listed a few ecus - none communicated and then in either Injection or additive, I looked again and had similar response)

Are you saying you cant communicate with the additive system?? If so how do you know there is no comms with the fuel cap switch?

--I can see the additive options, in a previous vehicle I could see how much was assumed left but I didn't see that screen, iirc it just oftered to reset so I backed out in case I went too far (I need to go back in and make better notes) fault was ADD02 Permanent Fault - Fuel Filler Cap Signal

If you did disable the Eolys & fill the tank with diesel you would soon know about it as the DPF would clog in no time as it wouldn't be able to regenerate properly.

-I don't intend to, it was just a passing thought in case the dpf had been defeated, would it be best to cut the Eolys (if only to save it).

The differential pressure will be under parameter measurements in the injection ECU menus, There will then be sub menus, cant remember exactly the description if its under exhaust system or de pollution.
As said above early additive system ECU's can be problematic, the normally work ok till the time comes to re set after refilling Then is just wont reset, out of all the ones i have replaced for this reason there has never been an issue with communication, it just wont reset the counters.

- - thanks ill have another look for the parameters. I've definitely smelled (smelt?) a whif of that slightly sweet pungent diesel aroma I've always assumed was a dpf - a skyactiv-d mazda that I recently decarbed the intake manifold (horrendous) had the same smell on each of its 50 mile (fifty!) dpf regens until I put cleaner into it..

As for the Webasto, I dont think I've ever seen a UK diesel model without one.

-I'm sure it did at one time, sadly it's long gone, but a recent thermostat change seems to have sorted out my heating. The fuel economy seems to have gone up too, although that could be due to a few reasons, the other thing I've done was swap a hot solenoid valve that was controlling the wastegate, not sure how much affect that would have. I've temporarily swapped it with the other valve and unplugged the bad one but at the risk of upsetting Marc and knowing what the other valve controls, I'll add the disclaimer that I will be grabbing a working valve from my SORNed Dispatch.


I've tried to answer individually in the quote above, hope it works. I will say though, if everything is likely to keep working I'm not overly concerned (yet), I have enough faults to hunt down without making more for myself. I'm 250 miles into this so far, long motorways, some very short journeys, a fair amount of hilly Welsh country roads and after warmup, a 4k rpm thrashing up and down a 2x 3 mile stretch of empty straight with a slight incline and then a gentle 6th gear 1.5k rpm cruise over the same route. So I guess the next 250 miles will show up any dpf problems if there's any.
Should I be concerned with the filler cap fault? or does it have a backup function based on distance travelled (eg. If it travels more than an average tank and hasn't detected the filler cap does it fire a shot anyway)
Are there common resolutions (sticky reed switch?) or is it more likely some wire chasing?

Edit: split the quotes to make it more readable.

[MixerFistit]

Just to follow up, as some info from me wasn't particularly helpful. I've had lexia back on and confirm the following :
Firstly, DPF differential is 0.0 regardless of rpm
I had it from idle to 3.5k (stationary). So I'm assuming it's been meddled with. The odd thing is that there's still average miles between regents etc so the concern is, will it try to inject diesel and cause a James Bond smoke screen if I don't ensure settings are correct. Appreciate talk of dpf meddling isn't welcome but I'm concerned if it'll be more harmful to leave it if it hasn't been done properly. And I'm ultimately just trying to reconstruct the history of the vehicle as best I can.

After it fails to perform a static regen, the follow up message is "No Dialogue with Ecu during initialisation"
The additive ECU parameters show:
Low Additive: Not Reached
Fuel Filler Cap: Absent
Dust Filter (FAP) Reset total additive qty: 165 g
Aditive tank reset total additive qty since last fill: 35 g
Particle filter downstream temp: 255 C

Then under Particle filter Info:
Status: Regenerated
Regen assistance request: Inactive
Cat converter upstream 752 C (!)
Downstream also 752 C
Particulate pressure difference: 0.0 mbar
Air temp: 20C (seems high)
Coolant temp: 75 C
A few things regarding air flow all 0
Total fuel additive qty: 165g
Distance travelled since last regen: 456km
Average distance of last 5 regens: 500 km

There is a double weld on the centre exhaust pipe, a bit further back from the DPF. The section between the 2 welds is only about the size of one. Of those half sized cans of beans.
In the repair history of the car there is mention of repair work to remove "modified section of centre pipe" but I'm not sure what purpose any mod there could've served, maybe nothing to do with DPF though.

[PaulC5]

On our cars with a dpf the exhaust tail pipe is clean inside. If yours is covered in soot then that could indicate the dpf has been drilled through.