Code P047164 OM651 - any ideas?

[moj91]

My '09 C250 Cdi is showing Code P047164 when checked using Icarsoft mb2. Text is 'Exhaust Back Pressure Sensor 1 has a malfunction. There is an implausible signal.'

Now, most of you will be shouting 'get it on star' and yes you are right.. however I was wondering if this code means the DPF differential sensor? Its been 50k since the last one failed (at around 50k..), and this code (and limp mode) happened first at around -9c in Austria in Feb, I have heard the cold 'finishes them off'?

I have also heard about wiring problems cropping up at this age of car in relation to the DPF sensor, does anyone know where about's the wires fail so i can inspect? I've already had a couple of wires rub through elsewhere...

Since then I have had intermittent limp mode (no EML, clears on restart) however now limp mode is becoming more common and the code wont clear - so i'm worried about failing DPF regens and the hassle which comes from it.

I do have a brand new DPF diff. sensor but don't want to change it if i'm barking up the wrong tree with that fault code? There seems to be little on the net relating to this particular code? I do tend to find the icarsoft is pretty accurate in pinpointing the issue, but i don't know which actual sensor it is suggesting is at fault.

Any input welcome to save a wasted job/investigation, Thanks!

 

[Wighty]

My exhaust back pressure sensor is up by the turbo on my E320cdi . They do have a small pin hole underneath which can block up , you could try spray cleaning this first ? Mine is about £50 new

 

[moj91]

My exhaust back pressure sensor is up by the turbo on my E320cdi . They do have a small pin hole underneath which can block up , you could try spray cleaning this first ? Mine is about £50 new

I might see if i can find that tomorrow when i have the spanners out, what did you clean yours with if mine is the same? Contact cleaner?

 

[Wighty]

I might see if i can find that tomorrow when i have the spanners out, what did you clean yours with if mine is the same? Contact cleaner?

I think I used carb cleaner or maf cleaner ? Mine was a deep socket 22 or 24mm (quite big anyway )

 

[moj91]

On the Om651, the 'Exhaust Back Pressure Sensor 1' (sensor B60 i believe) is located on the EGR, right at the rear right hand side of the engine, by the bulkhead, just under the heater matrix hose. I took it out some months ago, soaked it in brake cleaner overnight and refitted after cleaning the connector. Seemed to solve the issue for a few months but came back with vengeance this week, also causing the EML, limp mode and the DPF to fail to regen.

I took the connector off, cleaned and refitted as it seems to attract dirt, but no improvement. I then checked the sensor readout on the icarsoft, and found that the value barely changed under revs/load. I took the sensor out again (24mm deep socket needed) and it was pretty filthy, so opted for a replacement (£60, local dealer in stock, PN: A0091535128 'Pressure Transmitter' and also bought the matching o-ring for good practice). Pretty easy and quick to change, just be careful to not drop the sensor down the back of the engine. On change the fault code cleared and stayed away, the sensor data stream now shows a much wider variation of value and the engine runs noticeably smoother, followed by the car immediately performing a DPF regen itself.

Hopefully the new sensor will last and I don't have a sooting problem which will clog it up again soon.

This link (translated) from a russian site outlines the same issue on the same engine in a CLS 250 CDI. The dealer said they sell a fair few of these sensors, so i guess its a common issue. https://www.drive2.ru/l/10237028

 

[Wighty]

On the Om651, the 'Exhaust Back Pressure Sensor 1' (sensor B60 i believe) is located on the EGR, right at the rear right hand side of the engine, by the bulkhead, just under the heater matrix hose. I took it out some months ago, soaked it in brake cleaner overnight and refitted after cleaning the connector. Seemed to solve the issue for a few months but came back with vengeance this week, also causing the EML, limp mode and the DPF to fail to regen.

I took the connector off, cleaned and refitted as it seems to attract dirt, but no improvement. I then checked the sensor readout on the icarsoft, and found that the value barely changed under revs/load. I took the sensor out again (24mm deep socket needed) and it was pretty filthy, so opted for a replacement (£60, local dealer in stock, PN: A0091535128 'Pressure Transmitter' and also bought the matching o-ring for good practice). Pretty easy and quick to change, just be careful to not drop the sensor down the back of the engine. On change the fault code cleared and stayed away, the sensor data stream now shows a much wider variation of value and the engine runs noticeably smoother, followed by the car immediately performing a DPF regen itself.

Hopefully the new sensor will last and I don't have a sooting problem which will clog it up again soon.

This link (translated) from a russian site outlines the same issue on the same engine in a CLS 250 CDI. The dealer said they sell a fair few of these sensors, so i guess its a common issue. https://www.drive2.ru/l/10237028

Good job buddy . I better get on and do mine !

 

[screem]

On the Om651, the 'Exhaust Back Pressure Sensor 1' (sensor B60 i believe) is located on the EGR, right at the rear right hand side of the engine, by the bulkhead, just under the heater matrix hose. I took it out some months ago, soaked it in brake cleaner overnight and refitted after cleaning the connector. Seemed to solve the issue for a few months but came back with vengeance this week, also causing the EML, limp mode and the DPF to fail to regen.

I took the connector off, cleaned and refitted as it seems to attract dirt, but no improvement. I then checked the sensor readout on the icarsoft, and found that the value barely changed under revs/load. I took the sensor out again (24mm deep socket needed) and it was pretty filthy, so opted for a replacement (£60, local dealer in stock, PN: A0091535128 'Pressure Transmitter' and also bought the matching o-ring for good practice). Pretty easy and quick to change, just be careful to not drop the sensor down the back of the engine. On change the fault code cleared and stayed away, the sensor data stream now shows a much wider variation of value and the engine runs noticeably smoother, followed by the car immediately performing a DPF regen itself.

Hopefully the new sensor will last and I don't have a sooting problem which will clog it up again soon.

This link (translated) from a russian site outlines the same issue on the same engine in a CLS 250 CDI. The dealer said they sell a fair few of these sensors, so i guess its a common issue. https://www.drive2.ru/l/10237028

This link belongs to me and you also can ask me in English

 

[Steve@Avantgarde]

If it is a DPF sensor, you still need it on star to update the software.

 

[screem]

If it is a DPF sensor, you still need it on star to update the software.

This is exhaust pressure sensor

 

[john campbell]

The exhaust back pressure sensor is common to fail and I did mine not long ago...... I also bought 2 sensors so I had one ready for the next time it goes. Once fitted take the car for a long run so the car will do a regen. Because of the location of the sensor they tend to get blocked with soot so it's good practice to give them a good run out to keep the soot low in the egr and that will stop the sensor from blocking up.

 

[screem]

The exhaust back pressure sensor is common to fail and I did mine not long ago...... I also bought 2 sensors so I had one ready for the next time it goes. Once fitted take the car for a long run so the car will do a regen. Because of the location of the sensor they tend to get blocked with soot so it's good practice to give them a good run out to keep the soot low in the egr and that will stop the sensor from blocking up.

I’ve changed once, and already long time have past and about 80 000 km- steel no problem, but I think the reason is whole ash oil or oil additives, because at that time I was using graphite oil. After sensor replace- start use usual oil According spec list 229.31 or 229.51 and now also om651 on GLK220, the same oil and for now now any problems