C4 Picasso DV6C - P1490

[RichardW]

My Sister's car, a 2011 1.6 HDi with the early DV6C engine (all injectors been replaced ) and just over 80k. DPF warning has been coming on randomly recently. I hooked it up to Diagbox, and just the one fault, P1490 DPF blocked or words to that effect. It is continuing to regen, and it says another 20k till it's full of ash, but the pressure looks high to me, we got 190mbar climbing the big hill just up the road from here. Pressure showing when the fault was set was only 135mbar... I will compare the live data on my 3008 which has the same engine, but I'm thinking it needs a new DPF* (or cleaning), unless anyone can convince me otherwise....? It might be worth checking the pipes to the sensor, and subbing in the one off my car for a test.

*Actually, since it's EGS and still on original clutch and needs 2 tyres as well, I'm erring towards making it someone else's problem!!

[lexi]

Where and what is the pressure being measured on your test? What ideal pressure are you looking for?

[RichardW]

Differential pressure across the DPF. I checked my 307 I recall up the same bit of road and is was certainly <150mbar. Marc posted some info on the fault code previously: viewtopic.php?t=62560 It says the code is set:

For a volume flow passing through the particle filter of 200000 l/h, the differential pressure is greater than 170 mbar for 10 s

For a volume flow passing through the particle filter of 300 000 l/h, the differential pressure is greater than 286 mbar for 10 s (Engine speed approximately 4000 revs/min)

For a volume flow passing through the particle filter of 500 000 l/h, the differential pressure is greater than 500 mbar for 10 s

Which is why it's a bit surprising that the pressure in the fault code is only 134mbar. I'm reasonably convinced the DPF is at fault. I wonder if a forced regen might improve it, no harm in trying I guess but there are new ones for only £90 on ebay, so it's not the wallet pain it once was!!