Technical [263] Fault code P1206-22 DPF related shenanigans 1.3 Multijet2

[clayts450]

Hi folks

I managed to blag a 1.3 Multijet2 Doblo 2018 for silly money as it was advertised as having DPF issues. First thing I did was change the oil and filter, and reset the oil counter using the pedal trick.

I can confirm it does indeed have DPF issues. Whilst the standard OBD readers only find P2002 (22), a VLink iCar Pro BL 4.0 plus CarScanner app on Android pointed the finger at P1206-22. Clearing the code does nothing - it's straight back on again as soon as the revs rise significantly.

Watching the differential pressure sensor readings in the wonderfully useful DPF Monitor app https://play.google.com/store/apps/details?id=com.kapron.ap.dpfmonitor&hl=en
I was able to ascertain that the pressure readings go off the chart. Here's some examples:

I took it for a long old drive on Saturday (with P1206 still present, so progress was slow), belted up and down the M1 a junction (J26->J25->J26) and parked up at a quiet industrial estate with the idea of clearing the P1206 quickly and forcing a regen with the pedal press trick. No dice. Mind you by this time the blockage was showing as 107%.

Weirdly, as I drove home very gently from the industrial estate (less than a third of a mile in a 20mph restriction) the van began regen, so I took it for a good old run down the M1 again (J26->J23A->J26) by which time the regen had fully completed (to 13% clogging), and the differential pressure was down again. Happy days, thought I....

Sadly my victory was short lived. As I am a national same day courier, I drive many miles. I drove to that London on the Sunday and after about 120 miles up came the P1206 code and P2002 code again. Clogging levels weren't massive, say 50%.

I drove all the way from Scratchwood Services (between J2 and J4) to Trowell Services (between J25 and J26) as the limp mode was manageable (poor weather conditions, everyone driving slow). Tried to reset the codes again, came up as soon as I left the services, no regen this time even though the temperature started rising (and subsequently went down again). Massive differential pressure readings again - reached as high as over 600Mbar. The one thing I did note that (when the engine was cool the following day) the oil level was right down on the dipstick - took a litre to refill. I'm hoping this isn't being sucked into the turbo, but one problem at a time.....

I have secured Multiecuscan and the various cables, but as this is a 2018 model I also need the SGW bypass cable, which I'm waiting on. I did take some readings on the DPF with read only access - never replaced, done over 600 regens in 78000 miles, last regn accurately recording, differential pressure reading 0 Mbar at ignition on/engine off, and around 50-70 idle. Clearly these readings are way too high. Differential pressure sensor voltages read fine (between 0.5 at idle and 4.5V at 2500rpm). Oil degradation level showing 94% which seems right, apparently the van has done three regens since I did that (it part did one on the way to Salisbury on the Thursday then threw up the codes, I suspect it part did one to London too, plus the full one I witnessed on DPF monitor).

Anyroad, plan of action:

- get engine to temp, maybe a 20 min 1 junction loop on the M1, clear codes with Multiecuscan once the SGW cable is in place, force regen, take it for a good old hoon once cooled.

Everything points to a full to bursting DPF.

I'm also wondering whether it's worth (once the first force regen is done) resetting the DPF and differential pressure sensor settings (ie 'replacing' them), doing a second foced regen and then another hoon to recalibrate. However, I'm wary that this may create more problems than it solves, so will hold off for now.

Thoughts ? Worth getting a DPF clean ?

And no, DPF delete and remap really would have to be the last resort. Given the DVSA's propensity for roadside checks, I can't risk a £2500 fine which is what commercial van drivers face if there has been DPF skullduggery. It really needs to be legit if poss (though the extra 20 horses would be nice, as would the improved MPG)

 

[clayts450]

Here's the fault codes

 

[clayts450]

The SGW cable arrived today, so it was time to see if a forced regen would work.

After getting the engine to temperature, I popped open the bonnet, fired up Multiecuscan, connected to the new OBD port which forms part of the SGW bypass cable.

Cleared the two codes (P1206-22, P2002-22), selected Forced Regen and execute and away we went (sorry for poor quality photos, done on my phone as I didn't want to touch the laptop in case I broke something) :



The engine then revved gradually up to 3500 rpm where it stayed for a good 10 minutes or so.




All it was doing at this stage was a normal regeneration as the clogging level got down to 10% . Eventually the forced regen began and started ticking upwards, with the DPF reaching an eye-watering 632 degrees C



Finally the rev counter dropped down to idle. Note the EML came back on during the process but the forced regen ignored it - in 'normal conditions' this would have stopped an active regen.



The screen I wanted to see:



What concerned me a little was the clogging reading now said 85%.....which was more than when I started. However, I had faith. I deleted the P1206-22 code which had popped up again (no P2002-22 this time, strangely).

The van did not chuck out vast plumes of soot or anything to be fair. It did make a nice dry spot on the road though



So, with the clogging level at 85% or so, the next thing I wanted to see was would it do a regen off it's own back. Four junctions up and down the M1 and I came back to this:



Yes. It had done that one all by itself without any intervention, completing as I came off the motorway - it had also got clogging down to a squeaky clean 15% (probably as good as it gets).

The differential pressure reading at idle was also more to my liking - 10mBar.

I'm not counting my chickens just yet - the proof as to whether it has worked or not will be when I do my next long journey for work.

I'll update when something or (preferably) nothing happens

 

[clayts450]

So, I took the van for a long old drive yesterday as part of my job. I didn't have my laptop with me so couldn't log on MultiEcuScan but I wass running the DPF monitor.

I did one quick Nottingham->Leicester->Nottingham job (71 miles) during which time the van did another little regen itself, all good, no EML.

Then I did Nottingham to London. During this time the back pressure shot up, with differential pressure sensor readings way too high. Eventually, the yellow light of doom came on. (earliest on the right, newest on the left)



Same codes as before, cleared whilst in London using CarScanner. Nope, popped up straight away again. By the time I was near home the pressure readings were silly high.

So, DPF is goosed I think.

Just searching online for an alternative to the gazillion quid replacement from Fiat - no dice. The only ones I can see are Euro 5, which is no good.

Has anyone had any luck sourcing one ?

 

[Abarthmultijet]

Had something simular with a Punto 1.3 multijet once, look for any split/cracked turbo or intercooler pipes. The owner and I didn't notice anything regarding performance.

Fixed the hose, took it for a long drive Italian style and has been good ever since (2.5 years ago)


But maybe too late and DPF is gone to meet their maker.

 

[clayts450]

Booked in for a DPF clean, probably won't make any difference, but got to give it a go.

The cheapest replacement (new) I can find is around £800. Even with this, taking what I paid for it, it's still a bargain van.

 

[clayts450]

Had something simular with a Punto 1.3 multijet once, look for any split/cracked turbo or intercooler pipes. The owner and I didn't notice anything regarding performance.

Fixed the hose, took it for a long drive Italian style and has been good ever since (2.5 years ago)


But maybe too late and DPF is gone to meet their maker.

I think you're right. I had the tell-tale hissing on the M1 after doing a DPF clean myself, and it was down in power (had similar on a Combo D - badly damaged intercooler) - no warning lights, no black smoke. Time to get underneath the van. Good shout, thanks !

 

[clayts450]

Done a few things with the van over the last week or so.

(1) Squirted some DPF foam spray into the DPF via the temp sensor at the top - that seemed to clear some crud out
(2) That's when I started getting the hissing - bogged down performance under load, so assumed boost leak. Not been able to identify as yet, but may have actually been a hiss from the join between the DPF and turbo due to it being 95-96% full - the hiss disappeared today)
(3) At this time the % filled of the DPF was around 95-96%. I came to learn on Vauxhalls (and therefore probably Fiats too) that:

• What conditions are required for the DPF to begin regeneration?
• Answer: The following conditions must be fulfilled for regeneration to begin.
• a.) Engine running since start >2 minutes.
• b.) Calculated saturation >80%.
• c.) Coolant temperature >70°C for at least 2 minutes.
• d.) No DPF-relevant faults stored in system.
• e.) A defined vehicle speed threshold must be exceeded in some cases
• (e.g. for 80%-100% loading, one time 100 km/h - 62mph), at loadings above 100% the speed does not matter.

The % clogged is just a random number that goes up with time/mileage, nothing more complex than that

(4) I'd cleared codes P1206-22 and P2002-22 after the DPF foam spray treatment, and they've not come back....yet

(5) Took the van out for a long run today, and had MultiEcuScan hooked up. As soon as the % loading went up over 100% the DPF temp increased to over 600 degrees C, and lo and behold the van regenerated itself. I wasn't doing mega speeds (between 0 and 65 mph, rarely any maintained speed levels over any distance due to stop-start traffic)

(6) The only thing that concerns me now is that differential pressure is still too high - at idle 10mBar (should ideally be between 0-5mBar I understand - even during regeneration it was hitting 100-200, ideally this needs to be between 10-50mBar I believe).

(7) Exhaust pipe is clean - no soot, so DPF is definitely working

I scooped up some data whilst on this drive, attached for any MES boffins to peruse at leisure. I'm still going through it to see if I can spot any trends.

I'll probably try another can of the foam cleaner, as the readings are definitely lower than they were before.

 

[Abarthmultijet]

The connection between the dpf and turbo usually doesn't leak, V-Band construction is very secure. Would really look for boost leaks. Check the pipe between the intercooler and gearbox area.

If the car does not throw any fault codes I would not pay to much attention to the data you provided.

 

[clayts450]

The connection between the dpf and turbo usually doesn't leak, V-Band construction is very secure. Would really look for boost leaks. Check the pipe between the intercooler and gearbox area.

If the car does not throw any fault codes I would not pay to much attention to the data you provided.

There didn't seem to be too much difference between actual and desired boost pressure, which kind of steered me away from a boost leak (that and a lack of a code), but I will have another prod around under the van - there didn't seem to be anything obvious on that particular pipe, but then it wasn't under load (engine off - even engine idling would be pointless, needs a smoke test ideally).

The other thing that struck me was maybe there's something going on with the actual diff pressure sensor pipes - if one of them was blocked or split, that could lead to erroneous differential pressure maybe ? Although if they were split, I would expect low diff pressure not high. If they were blocked - that might be different.

Thanks for your thoughts, definitely will look into further

 

[clayts450]

Just a small sample size of the turbo pressure at around 2500-3000rpm. In the short time I've owned the van it's never thrown an underboost or overboost pressure code - no turbo codes at all. The only codes are 1206 and 2002 - 1st level clogging exceeded (1206), 2nd level clogging exceeded (2002)

 

[jackwhoo]

If egr valve partially open when should be closed there will be a boost leak straight into exhaust system plus maf will read high leading to excessive fuel and so extra soot

 

[clayts450]

If egr valve partially open when should be closed there will be a boost leak straight into exhaust system plus maf will read high leading to excessive fuel and so extra soot

Thanks for this - very insightful. Yes, I noted the high pressure EGR was very slightly open by 0.4mm or so when it should have been closed - do we think that small amount would make that much of a difference? I didn't chart MAF, maybe I should have done ?

 

[jackwhoo]

further investigation a good idea.

 

[clayts450]

I'm not sure I grabbed the right parameters here, but it seems to me that slightly open EGR (9%) may well be partly responsible for the clogging. Be interested to know what the forum hive mind thinks.

Diff pressure in millibars is still too high for me

 

[clayts450]

Van is now at garage (overnight stay) for a proper DPF assessment. On the way there, it chucked up two turbo codes (P234 and P2563). The technician who's working on it suspects the throttle valve is sticking. Brief diagnostics I did on this (no records as I was trialling a Mucar Driverscan dongle) confirmed the same.

 

[clayts450]

News just in - needs a replacement turbo. Great.

 

[clayts450]

Turbo replaced plus oil feed/oil return and an oil/filter change (annoyingly I did one myself less than a thousand miles ago).

Differential pressures now reverted back to 'within limits'. Also did a passive regen itself at slow speeds on the way back from the garage - clogging went down from 75% to 20% or so : good to see.

Smoke test by garage found no leaks at all, but did discover turbo was completely goosed. Pulls like a train again now.

 

[jackwhoo]

It is good oil and filter changed again as turbo warranty would not be valid if oil and filter not changed

 

[clayts450]

It is good oil and filter changed again as turbo warranty would not be valid if oil and filter not changed

Correct.