A180 back pressure sensor fault

[Cookstar]

Hi Guys I am picking up back pressure sensor fault on ob2? Replaced engine sensor ran dfp clean and regen. Today did 30 minutes of motorway driving after clearing code then on restarting engine light in again. Engine sometimes only revs to 3 or 4k then frees itself? Egr maybe cleaning itself? Could pipe to sensor being blocked activate shut down?

 

[Deep4]

Hi Cookstar, interestingly enough my 2016 A180D has displayed the same error very recently (About a week ago - code P0470) for the Exhaust Pressure Sensor "A" Circuit. The same code came up on my car in January of 2020, and was displayed alongside code P0380 for the Glow Plug "A" Circuit (It turned out that the glow plug module was faulty, since the replacement this code did not return). I have never noticed this code come up during warm seasons, but that could just be a coincidence.

This time around the code has disappeared before I managed to book it in with a local specialist, I haven't noticed any changes in how the car operates, and it appears to be fine, but it will still go in for a check very soon.

I have found the below snippet from this article about how the sensor can fail, so it might well be a blocked pipe.

And just like the DPF, the sensor hoses can also become clogged from soot in the exhaust. When diesel particulate matter blocks one or both of these airways to the sensor, the sensor can no longer determine pressure changes accurately.

The article also includes quite a comprehensive guide on how to troubleshoot this sensor, and check the pressure in the pipes - just need to compare your values to the ones found in a service manual. If you have a multimeter, and would be willing to see what the sensor outputs, attach metal clips/needles to your probes using electrical tape to easily slide them past the insulation on the sensor.

Any universal pressure gauge with the correct adaptor should return a value, although don't expect pinpoint accuracy.

Perhaps somebody from the forum can point you to the right service manual to obtain the default voltages and pressures.

Hope this helps!

 

[Cookstar]

Yeah I'm getting good volts at back pressure sensor and it's new but now reading 0471 exhaust pressure sensor fault so my moneys on that and maybe rear exhaust sensors as I'm getting a 0470 still. Need to check volts at eps first? Will check psi on back pressure tube just to check that's not blocked?

 

[Cookstar]

 

[Cookstar]