Pressure sensor before the DPF

[compsyndrome]

Is anyone aware of the function of the said sensor? Not to be confused with the DPF back pressure sensor, which is 2 sensors in one.
Mine is not working. Confirmed by the dealership, but the car is actually not complaining.

[Variante Alta]

I think there are pressure differential sensors which assist the car in determining if and when the dpf requires a regen cycle or is plugged beyond spec. You might enquirer further with the dealership who diagnosed it for further info.

[compsyndrome]

Originally Posted by Variante Alta

I think there are pressure differential sensors which assist the car in determining if and when the dpf requires a regen cycle or is plugged beyond spec. You might enquirer further with the dealership who diagnosed it for further info.

Yeah, the DPF differential pressure is separate. The DPF wouldn't work without that. I have readings on it while the "pressure sensor before DPF is stuck on 7.xx PSI. The dealer simply offered to replace it for like $600.

[mrrsharma@yahoo.com]

Did you get your EGR cooler replaced under the recall?

I had the same note when they returned the car. The exhaust pressure sensor had an implausible reading. But no error code was set. Thru bmwlink it looks like it just reads 0 psi/ 0 bar on my X5.

Not sure what the purpose is for the sensor but it looks fairly easy to replace

P/N: 13628507634

I think it’s like $50 on ECS tuning. Since it’s not causing a code and regening I haven’t messed with it.

[compsyndrome]

Originally Posted by mrrsharma@yahoo.com

Did you get your EGR cooler replaced under the recall?

I had the same note when they returned the car. The exhaust pressure sensor had an implausible reading. But no error code was set. Thru bmwlink it looks like it just reads 0 psi/ 0 bar on my X5.

Not sure what the purpose is for the sensor but it looks fairly easy to replace

P/N: 13628507634

I think it’s like $50 on ECS tuning. Since it’s not causing a code and regening I haven’t messed with it.

I don't know why the heck I don't get forum notifications.
SO, yes, it was when they replaced my recalled EGR cooler. However, I had noticed even before that that sensor shows a constant and unlikely value. No codes, yes.
Also, I had stared at that very same diagram for probably hours and still can’t figure out where the listed sensor is plugged.

[mrrsharma@yahoo.com]

compsyndrome

I’ll snap a picture of it, it’s visible from the passanger side of the engine bay once you lift the engine cover off. It’s right above to the primary EGR cooler, the sensor is clipped into a plastic housing.

[compsyndrome]

Originally Posted by mrrsharma@yahoo.com

compsyndrome

I’ll snap a picture of it, it’s visible from the passanger side of the engine bay once you lift the engine cover off. It’s right above to the primary EGR cooler, the sensor is clipped into a plastic housing.

Thanks. In what compartment/pipe does it measure the pressure?

[mrrsharma@yahoo.com]

compsyndrome the exhaust pressure sensor pipe connects to the end of the exhaust manifold right before it goes to the turbo.

I’m wondering if the pipe or the banjo bolt is blocked up with soot. If you hit it with some compressed air it might clear the passages.

In the first gen N57 it looks like they had this sensor as a pre-dpf pressure sensor and a single different sensor read out for the post dpf sensor. But looks like this sensor doesn’t do much at this point.

[compsyndrome]

Originally Posted by mrrsharma@yahoo.com

compsyndrome the exhaust pressure sensor pipe connects to the end of the exhaust manifold right before it goes to the turbo.

I’m wondering if the pipe or the banjo bolt is blocked up with soot. If you hit it with some compressed air it might clear the passages.

In the first gen N57 it looks like they had this sensor as a pre-dpf pressure sensor and a single different sensor read out for the post dpf sensor. But looks like this sensor doesn’t do much at this point.

Thanks, that helps. And you are probably right!

[mrrsharma@yahoo.com]

compsyndrome

Maybe I should clean/change mine out

[compsyndrome]

Originally Posted by mrrsharma@yahoo.com

compsyndrome

Maybe I should clean/change mine out

Thank you. This seems to indicate that the sensor is needed to adjust the EGR rate. I hope to turn EGR off at some point so I may leave the sensor alone.
BTW, is this engine manual something that's available online?

[jnash467]

I think I’m having the same issues the rest of you are. The codes I’m getting are 290B00, 290900, 28DE00, and 2AB600. When I searched for those 4 codes together, the results pointed towards the Back Pressure Sensor.
I too had my EGR Cooler and EGR replaced under the recall, but these codes were showing up before. No drivability issues, or fuel economy loss.

[Clifton]

Originally Posted by mrrsharma@yahoo.com

Maybe I should clean/change mine out

Did you ever pull yours and clean? Any tricks or tips?

[mrrsharma@yahoo.com]

No I didnt. I never got a code and everything looked fine.

[jnash467]

Yesterday I pulled the pressure sensor off the hose, and blew a little air on it. Not much soot inside of it. I could still see shiny metal in it. I then put the end of my used a variable pressure nozzle and while holding it inside the end of that rubber hose, I applied some air pressure. I was immediately met with resistance, there was no air blowing through it all.
So I am guessing it’s time to order some parts. I would take it off and clean it, but for a couple of hundred bucks I might as well replace the sensor and hose.

[Clifton]

Originally Posted by jnash467

Yesterday I pulled the pressure sensor off the hose, and blew a little air on it. Not much soot inside of it. I could still see shiny metal in it. I then put the end of my used a variable pressure nozzle and while holding it inside the end of that rubber hose, I applied some air pressure. I was immediately met with resistance, there was no air blowing through it all.
So I am guessing it’s time to order some parts. I would take it off and clean it, but for a couple of hundred bucks I might as well replace the sensor and hose.

GREAT INTL on this! Do you mind posting some pics and any steps you took?

This might be a good thing to add to our ongoing Diesel discussion thread as a maintenance item, much like cleaning the SRC nozzle.

[jnash467]

Sorry, I did not take any pictures of how I did it. It did dawn on me after.