DPF / Diagbox Advice Please

[spacebiscuit]

I recently had the DPF changed on my vehicle after 70k miles by a local garage. Replacement was an oem match and not a cheap low end item. Car was fine but after 5 days of short journeys a generic engine fault came up with 'repair needed'. I bought myself a full chip ODB2 reader and Diagbox v9 software. It seems that the ECU has not been told that the DPF has been replaced.

When I go into Exhaust sensor readings it displays the old filter's mileage (110,392 km). Because the counter wasn't reset when the new DPF was fitted, the figures have glitched out into a software overflow state:

• Total Soot Weight: 370.055 g (Normal limit is usually under 40–50 grams)
• Cinders Clogging Rate: 6,150.003% (Physically impossible; should never exceed 100%)
• Differential Pressure: 38.000 mbar at idle (A brand-new DPF should ideally read under 10 mbar; 38 mbar indicates high restriction to the ECU, reinforcing its refusal to reset).
• Exhaust Gas Temperatures: 71°C and 74°C (Normal, logical readings for a recently running engine, confirming the temperature sensors are physically working).

When I go into the repair menu:

CMM_MD1CS003_EURO6_4 -> Repair -> Replacement Parts -> Work on the Emission Control Circuit -> REPLACEMENT OF THE PARTICLE FILTER DIFFERENTIAL PRESSURE SENSOR

The operation won't start - Diagbox says 'outside of range'.

Does anyone have any ideas? Is there a software workaround? AI suggests it is because the differential pressure is so high and suggests I disconnect the sensor which will trick it into thinking the pressure is at 0.

My car is DS7 1.5 - I posted here because there is far more activity on this subject, I hope that's ok - any suggestions welcome.

Thank you.

[shtu]

Post the specific version of Diagbox, and as much detail as you can of the vehicle you are using it on.

7.x versions to about .57 or .62 can perform coding operations (as opposed to reading data) without online connection to Stellantis. I suspect the 9.x version you have requires a connection to do so.

[Rp0thejester]

Damn shtu, I was typing that!

[RichardW]

Take it back and get them to fix it would be the first choice.

Is the pressure reading zero at key on with the engine off? You don't really want to reset it as new if the soot / pressure is high as it might then fire off a regen and break the new one. Having said that, if only 5 days and low miles, then it can't have dumped too much soot in it. What was the original fault?

[spacebiscuit]

The vehicle is a 2018 DS7 69k. Diagvox v9.186v.

2 years ago I had the Adblue changed, a year later I had the Adluue warning come up again and the count down clock. A mechanic came out to me and found soot in tail pipe suggesting the DPF had FAILED, likely cracked he said due to failed regen cycles caused by mainly doing short journeys.

So I had the DPF changed and that is where I am at. The car drives fine and the fault is cleared but I am not using it until issue is resolved.

The pressure is displaying 38 bar when engine isn't running. If I disconnect the pipes to the sensor would this reveal anything.

I will see the mechanic tomorrow, I think they have Snap-on software.

[shtu]

OK, at that age and Diagbox version I don't think you can make any changes without internet access to the Stellantis mothership and spending money to do so.

You -could- try using an older version. It's 7.57 or .62 I use, but that's on a 2012 car so I've no idea if that would help.

-Which- sensor is showing 38 bar?

A DPF differential pressure sensor at 38 bar with the engine off = problem. If it is that one, disconnect the pipes (pay attention which goes where) and see, but that sounds like a broken sensor to me. (I had one that read a few millibars with engine off) You should also be able to make the reading change by sucking/blowing on one of the ports.

Personally, I think the person that fitted the DPF should be resolving this. The replacement part coding is well-enough known.

[windy1603]

On a number of PSA cars the cinder count is derived from the additive used data, which is why they recommend refilling fluid when changing DPF. I changed my sons DPF on his DS5 and cinder ammount/Km's stayed the same until we refilled Additive and reset the counters

[shtu]

Yeah, the whole thing is guesstimated except for the DPF differential pressure.

Absolute rubbish.