2010 C250 CDi DPF Pressure Sensor

[midsomerjambo]

Hi all,

Since I've had my 2010 C250 CDi (10 years) I've replaced or had replaced the DPF pressure sensor 3 times. The last time was when I did it myself about a year ago and I noticed the spring clips holding the hoses in place hadn't been refitted by the garage that did the last one. Thinking this might be a contributory factor, I sourced a couple and fitted them when I fitted the new DPF sensor. About a week ago I started having issues with going into limp mode (and occasionally, the engine warning indicator coming on). If I stop the car and restart the engine, it often will go back to normal running mode but if I'm parked up overnight, often as not it'll be back in limp mode when I start up in the morning. I'm able to clear the fault codes with my OBD dongle and the DashCommand app when the EWI comes on (the stop/start tactic doesn't work if that's the case) but the recurrent fault code is the DPF sensor (P2454 Diesel Particulate Filter Pressure Sensor A Circuit Low). Sometimes the fault code shows up in the Pending list and I've no idea what that means so I'd appreciate a heads up on that. The last DPF sensor I fitted was a genuine Bosch item and I'm surprised to be getting issues with it so soon (at, all if I'm really honest). Does anyone know if the fault code is a red herring or are these components really so unreliable? Could the fault actually lie somewhere other than the sensor? If the fault was actually somewhere else, why would it be fine for a year or so after replacement and then go tits up again?

Puzzled, MSJ

 

[Corty]

I to have a c250 and have very recently experienced the same issues. I plugged in my icarsoft scanner when the car was in limp mode and it said the dpf is full and also brought up a code for the differential pressure sensor. I replaced mine with a bosch one and had a dpf regen done at my local indie. Then like you it would still occasionally go into limp mode but would clear when I restarted the engine. I plugged the scanner back in and it showed the sensor was faulty with a code 2453. I replaced thus under warranty and now (touch wood) all seems well. So yes even new bosch ones can be faulty. It's possible that the sensor could be getting clogged with soot maybe, especially if regen is not being carried out correctly due to the sensor not being to tell the ecu what the current soot/Ash content of the dpf is.

 

[chiefsittingduck]

apparently the Bosch ones arent sensitive enough so best to buy gen Merc ones.. so im told