ADM & DPF Sensor V70 1.6D Drive

[Gazzamit]

Hello,

Here is a quick run though of the background to new DPF Sensor related issue. I can tackle some jobs after research, however, I’m not a mechanic.

DPF Sensor DTC
I bought the car around 130,000 miles just after the ADM fluid was topped up and counter reset in VIDA. Presume that car had new DPF at some point already.

All good till 180,000 and then had DPF related error again (150,000 miles recommended DPF replacement). Had a new DPF fitted and counter reset.

Now on 195,000 miles and getting this error message and limp mode:

ECM-P245300 Diesel Particulate Filter Differential Pressure Sensor Circuit Range/Performance.

Interestingly, when in limp mode the car always shows DPF sensor values from about 5hPa to about 100hPa under load, however, outside limp mode it is fixed at 20hPa after DTC reset. I presume that his is a default assignment value if there is an error like above recorded in the ECM. Can anyone confirm this?

Replace DPF Sensor
I bought a cheap DPF sensor and a simple off-car resistance test between pins gave different values to old sensor so I fitted the new DPF sensor. Back probed three sensor leads and got 4.5V supply, Earth and 0.48V which I presume is signal (seems to match other values found online so presume circuit is good).

I deleted OBD errors and car out of limp, however, the error is still there after 200miles (mixed with 150 miles on motorway).

I have ordered another sensor from Volvo and will update here with results. Hopefully this sensor will resolve error.

Can’t Clear the P245300 Error Code
If this Volvo sensor doesn’t work, is there anyway to reset this DTC P245300 error as it is persistent? (Nothing worked so far so I tried a DPF counter reset but didn’t work). Like I mentioned above, the DPF pressure sensor gives out readings when the car is in limp mode, however, it returns to 20hPa when DTC reset and car goes out of limp (error code still remains and car goes back to limp after a few days and sensor shows values again).

ADM level not changed over 65,000 miles
As far as the ADM goes I removed the three ADM tank bolts and could tell when shaking that there is plenty of fluid in it. I disconnected the output feed and ran the VIDA command to fill the feeder hose. I could hear the ADM pump running and fluid exited the ADM tank. I also checked in VIDA the level and its 15/15 and it was definitely reset when I got the car (and I reset it myself two years ago as a test and its not reduced at all in last 2 years).

I think after these tests that the feeder hose may be blocked, however, I’m not really up for dropping the fuel tank to check. Does anyone know if there is a way to check feeder hose is clear? Has anyone ever unblocked feeder hose or had a blocked one? Can air be blasted through it or something like that?

I know that the ADM has an internal pump and I think that the feeder hose terminates in a mechanical injector in the fuel tank according to VIDA (not sure what a mechanical injector is or if it can be unblocked without removing fuel tank).

V70 is still regenerating
Interestingly, the V70 is still regenerating. VIDA graphing shows DPF temperature reached 630 degrees and that the recorded value for soot was then reset from 11g to zero. At this point the temperature reduced to around 350 degrees.