NOx sensor fault

[kjohnr2001]

Hi - went to get our 2017 T28 T6 remapped and been informed that the NOx sensor was faulty, therefore the remap couldn't be carried-out.
The van has 66k on the clock, any thoughts on the best place/brand?
Cheers all...

 

[T65475]

Hi..... I too have the dreaded eml and the obd11 is advising of a faulty nox sensor. Really interested how this one goes as I have heard they are quite pricey to replace ??

 

[kjohnr2001]

Bought one from fleabay for £80, Bosch - will let you know when I get it fitted….
Cheers

 

[T65475]

Brilliant. I may have to join you anytime some stage.

 

[mmi]

obd11 is advising of a faulty nox sensor.

What exactly is reported? The fault code?

 

[T65475]

 

[mmi]

I think there is nothing wrong with the NOx sensor. The sensor indeed reports elevated NOx levels but hard to believe replacing it would change anything.
I would first check if engine software is up to date. Please post engine details - under Control Units > Engine > Info.

 

[T65475]

 

[mmi]

There is a software update for this engine which will cure the original P20EE issue.

Welcome to VAG-Flashinfo!

VAG Flashfiles Informations - Version check of VAG ECUs - Update check for Audi, Seat, Skoda and Volkswagen

vag-flashinfo.de

[T6_measured] NOx emissions, AdBlue consumption, DPF regeneration - Before and after ECU update

Introduction An update campaign for T6 EU6 diesel engines took place in 2019-20. Affected engines were on van of model years MY16-MY18, including some of MY19. For M1 class (passenger carriers, VIN WV2...) the update was an official recall. For N1 class (VIN WV1....) the update was not...

www.t6forum.com

 

[T65475]

That's amazing. Thank you.... how do I get the software update.... do I need to take it to a vw commercial centre?? Thank you again !!

 

[T6Paul]

That's amazing. Thank you.... how do I get the software update.... do I need to take it to a vw commercial centre?? Thank you again !!

Yes, that’s where I got mine done.

 

[Grim Reaper]

I get that at times, I just clear the codes out and carry on, seems it throws a code once every 1500 miles or so, not worried about it.
The other one that comes up occasionally is Urea percentage 0 or something like that, despite having added new adblue recently. Again, clear the codes and it carries on as if nothing has happened until next time.
My van is going nowhere near a dealer anytime soon.

 

[mmi]

how do I get the software update.... do I need to take it to a vw commercial centre??

I would expect any VW garage can do it.

 

[mmi]

The other one that comes up occasionally is Urea percentage 0 or something like that,

Would you care to share a snippet from VCDS scan?

 

[NorthernT6]

I get that at times, I just clear the codes out and carry on, seems it throws a code once every 1500 miles or so, not worried about it.
The other one that comes up occasionally is Urea percentage 0 or something like that, despite having added new adblue recently. Again, clear the codes and it carries on as if nothing has happened until next time.
My van is going nowhere near a dealer anytime soon.

Same here, been getting the nox error code for the last year, Eml light on. Clear it with carista and pops back up couple months later. Don’t want an update as I don’t want to lose the map!

 

[Grim Reaper]

1 Fault Found:
31103 - SCR NOx Catalyst Bank 1
P20EE 00 [236] - Efficiency too Low
MIL ON - Intermittent - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 3
Mileage: 19937 km
Date: 2061.01.26
Time: 15:48:23

Engine RPM: 1503.50 /min
Normed load value: 42.0 %
Vehicle speed: 83 km/h
Coolant temperature: 89 °C
Intake air temperature: 16 °C
Ambient air pressure: 990 mbar
Voltage terminal 30: 12.078 V
Unlearning counter according OBD: 40
Air mass at air mass meter 1: 100.8 kg/h
Outside temperature sensor 1: B1: raw value: 15.5 °C
Mass airflow sensor 1 bank 1 airflow: raw value: 559.5 mg/stroke
Throttl.valve adapt. 1 bank 1: posit feedback - Actual value: 0.13 %
NOx sensor before SCR cat conv: offset correction factor: 0 ppm
NOx sensor after SCR cat conv: offset correction factor: 189 ppm
Reducing agent quality sensor: urea concentration: 0.00 %
Reducing agent quality sensor: raw temperature value: 0.0 °C

 

[Grim Reaper]

From a couple of years ago..
2 Faults Found:
33262 - Reductant System Performance Bank 1
P204F 00 [100] - Malfunction
Intermittent - Not Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 1
Mileage: 11171 km
Date: 2045.01.23
Time: 13:54:47

Engine RPM: 1887.75 /min
Normed load value: 31.8 %
Vehicle speed: 104 km/h
Coolant temperature: 90 °C
Intake air temperature: 11 °C
Ambient air pressure: 1000 mbar
Voltage terminal 30: 12.070 V
Unlearning counter according OBD: 40
Simulated particle filter surface temperature: 299.0 °C
Reducing agent fill level sensor: act. value: 98 mm
Sensor for reducing agent tank temperature: temperature: 16.3 °C
Calculated NOx concentration behind turbocharger: 0 ppm
NOx sens.dwnstrm.SCR cat conv: NOx conc.: 40 ppm
Reducing agent quality sensor: urea concentration: 0.00 %

31103 - SCR NOx Catalyst Bank 1
P20EE 00 [236] - Efficiency too Low
MIL ON - Intermittent - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 6
Mileage: 10965 km
Date: 2045.01.23
Time: 06:39:57

Engine RPM: 2019.50 /min
Normed load value: 58.0 %
Vehicle speed: 111 km/h
Coolant temperature: 90 °C
Intake air temperature: 9 °C
Ambient air pressure: 1000 mbar
Voltage terminal 30: 13.390 V
Unlearning counter according OBD: 40
Air mass at air mass meter 1: 133.2 kg/h
Outside temperature sensor 1: B1: raw value: 8.0 °C
Mass airflow sensor 1 bank 1 airflow: raw value: 555.0 mg/stroke
Throttl.valve adapt. 1 bank 1: posit feedback - Actual value: 62.35 %
NOx sensor before SCR cat conv: offset correction factor: 0 ppm
NOx sensor after SCR cat conv: offset correction factor: 125 ppm
Reducing agent quality sensor: urea concentration: 0.00 %
Reducing agent quality sensor: raw temperature value: 0.0 °C

 

[T65475]

I would expect any VW garage can do it.

Well. Contacted the vw dealer... they have checked and no outstanding recalls so they are saying its not needed.... how do you get through the door?? Do you think an independent could do it was vcds?? I am so confused by vw and their strange operating practices

 

[mmi]

they have checked and no outstanding recalls so they are saying its not needed..

True - it's not a recall for this engine. Instead the update is categorised as "available" - especially when customer is experiencing the P20EE fault.

Do you think an independent could do it was vcds??

Unfortunately VCDS does not have software loading capabilitity. Other tools are needed - e.g. ODIS at VW, or VCP VCPSYSTEM &reg :: VCP CAN PROFESSIONAL SYSTEM
VW would be the most convenient option - if they just would know how to use their tools

 

[kernowcoles]

Just got the same fault on Carista on my 2018 T32 150ps LWB, just 1 week after buying it approved used from a VW van centre.

Local VW won't tell me if fixing it would be covered by warranty unless I pay for them to diagnose it themselves.

Do you know if replacing the sensor and/or the software update would be covered by warranty?

Very new to all of this! First time owner!