[gpdriver]

Vehicle management -> Troubleshooting -> Function Structure, next find "exhaust gas pressure sensor"
In ABL choos Functional check, and compare pressure to ambient pressure.
Many times i did have exhaust backpressure sensor that shows 1040 hpa, compared to atmospheric sensor showing about 1000 hpa. Permissible difference is 20 hpa.

I tried now with another sensor. Now it shows -15mbar when engine is off or when hose is disconnected. 

In ABL i have: 
Atmospheric pressure: 1029 mbar 
Charge pressure: 1059 mbar
Exhaust backpressure: 1014 mbar 

Can it be charge pressure sensor?

h...try to reflash .maybe softwre is "tuned"

[evgenijj]

This sensor maybe cloged.

[michalkow]

To be sure I will change sensor for new one, often after dpf problem sensor also is broken, it's not expensive.

[Krysiaman]

Guys, please read what I wrote. Almost every question was answered earlier. Car is stock, iLevel from 2018, detached sensor shows same value with pipe detached (when engine off) and I sensor is NEW OEM and I tried few new parts (2 OE, 1 Hella, 1 Febi and 3 used OE). None of them was showing 0mbar when engine is off.

The problem is that value should be near 0 when engine is off but it isn't.

[unicoil]

Did you check DDE plug connections/pins for corrosion and damage. Sensor plug for supply voltage, ground and signal? Is atmospheric pressure sensor value plausible?

[typer]

Vehicle management -> Troubleshooting -> Function Structure, next find "exhaust gas pressure sensor"
In ABL choos Functional check, and compare pressure to ambient pressure.
Many times i did have exhaust backpressure sensor that shows 1040 hpa, compared to atmospheric sensor showing about 1000 hpa. Permissible difference is 20 hpa.

I tried now with another sensor. Now it shows -15mbar when engine is off or when hose is disconnected. 

In ABL i have: 
Atmospheric pressure: 1029 mbar 
Charge pressure: 1059 mbar
Exhaust backpressure: 1014 mbar 

Can it be charge pressure sensor?

What backpressure is at 2000rpm and cut-off engine speed?

[Krysiaman]

There will be no more updates from me
Decided to go for S169A and removed DPF. Filter inside wasn't damaged physically but somehow when car did regeneration backpressure values stayed the same all the same.

Now there is no problem

[Rolzs]

Take both sensors on bench, supply them and messure presistance. I beliew back presure sensor is resistance based.
Then you will see, maybe you have dme damaged or some software issue.