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Steve S

Another DPF issue

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Looking for a bit of advice please. My car is a 2007 E61 with N47 engine and has done almost 180,000 miles and the DPF warning came up on the iDrive. I have fault codes 452Aand 4D4A which I understand are just mileage warnings that the DPF may be near the end of it's life and don't relate to any lack of function of the DPF. I have checked some of the sensor data and it says last regen 229 km ago, which is since the first appearance of the DPF warning, so I think its still being cleaned. The differential pressure is less than 10 hPa at idle and rises to about 35 hPa at 2000 rpm. These seem OK to me. The car runs fine. Any thoughts, is my DPF time expired?

 

There was another code present, P14A3, which I believe is Pressure of DPF implausible to atmospheric pressure or boost pressure. I cleared the code and it hasn't come back, so might be historic. However, checking some of the other pressures monitored I noticed there is an Absolute pressure before turbine, which is showing 500.11 hPa and this value doesn't change whether the engine is running or not, so clearly there is a fault somewhere. From the name of the sensor it suggests it is used to measure the pressure drop across the turbine of the turbocharger and as its an absolute pressure maybe it's used in conjunction with the DPF upstream pressure. To read a pressure the sensing line to the pressure transducer would have to be in the exhaust manifold or the turbo and I don't see anything in those locations. It could be part of the EGR valve assembly I guess as that sees manifold pressure. Does anyone know where the  sensor for the absolute pressure before turbine is located?

 

Regards,

 

Steve

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What @GoNz0 says for the DPF. I've reset mine to zero before. Regens as normal.

On your other query, I don't think there is a sensor before the turbo on our N47s but I think there may be on other models (M57). What software are you using that shows this? I'm guessing now but it may be an irrelevant placeholder for other engine variants.

 

Keliuss

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GoNz0 & Keliuss,

Thanks for the replies. I'll try resetting the DPF timer, but so far I have only used an OBDII scanner on the iphone, which has limited capability, but is easy to use. It can read and reset codes and access sensor data, but I don't think I can reset the DPF. I have the DIS software, it's on a rather old notebook and have been able to connect in the past, but not very reliably. I'll try that next.

The lack of a sensor for the pressure before the turbine could explain the strange and fixed value I'm getting. 

Thanks again.

 

Regards,

 

Steve

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