Faulty NOx Sensor 2: Causes & Fixes

001650 - Spark plug, cylinder 2 (Q11)
P0672 - 000 - Electrical fault in the circuit.
Environmental conditions:
Error status: 01100000
Error priority: 2
Error frequency: 1.
Lost Count: 255
Mileage: 97193 km
Time: 0.
Date: 2059.14.02
Time: 13:14:56

Environmental conditions:
Speed: 0 RPM.
Speed: 0.0 km/h
Voltage: 11.63 V
Temperature: 9.0°C
Binary value: 00110000
Time: 2.52 s
Temperature: 9.0°C

008863 - Sensor 2 for NOx bank 1.
P229F - 000 - Implausible signal - Intermittent - Warning light ON.
Environmental conditions:
Error status: 10100000
Error priority: 2
Error frequency: 3.
Lost Count: 255
Mileage: 98926 km
Time: 0.
Date: 2063.14.06
Time: 15:48:32

Environmental conditions:
Speed: 2300 RPM.
Speed: 61.0 km/h
Voltage: 13.83 V
Lambda: 99.4%
(no unit): 255.0
268 ppm.
(no unit): 0.51


Readiness: 1 1 0 0 0

Hello.
This afternoon, while starting in first gear on my Passat 3C Variant (manufactured in 2009), the clutch slipped and jerked three times. After that, it seemed to be working normally again.
It's possible that my battery is failing, and this error message appears during the preheating process, as indicated above.
Furthermore, after driving for a few kilometers, the NOx error message appeared.

After approximately 200 kilometers, the NOx emissions reappeared.

Is this then defective, and is it located outside of the AdBlue tank system? About a year ago, I had a faulty AdBlue pump.

Thank you. Best regards.
Chris.

008863 - NOx sensor 2 for bank 1.
P229F - 000 - Implausible signal.
Environmental conditions:
Error status: 01100000
Error priority: 2.
Error frequency: 1.
Lost Count: 255
Mileage: 99142 km
Time: 0.
Date: 2063.14.08
Time: 14:48:00

Hello,

There is a Technical Service Bulletin (TPI) regarding the NOx sensor on the Passat: 2033680.
Ersatz durch verbesserte Version. Go to the .

Best regards, Rainer.

So, I'm going to order it from..., and I hope to install it myself and be happy with the result.

Thank you.

Chris.

First, check if your vehicle is affected and rule out other potential causes of the problem (e.g., damage to wiring caused by rodents).

I'll take a look underneath tomorrow and check the wiring.

What I noticed earlier when I was looking down is that the hole in the middle of the AdBlue tank seems to be whitish again.

It was exactly the same situation last year when the AdBlue pump was replaced.

But then the error message appeared, showing a distance of 1050 km and the remaining range, and the fault code indicated a problem with the exhaust gas recirculation pump.

Only the pump was replaced; everything else is from the year 2009.

Okay, the wiring is fine, the connectors are also good, and there's nothing visibly wrong with the sensor itself...

At VW, it's €489...

Now I've seen some on an online platform. New ones start at around €120 to €250.
But they can't tell me whether they are suitable for my Passat or for which vehicles they are intended.

Does anyone here happen to know?

03L907807 T 035WK9 6798 Continental 05/0015 21.11.13

Regards,

Chris.

The safest way is to have the ET number looked up for you by , providing the VIN.

Unfortunately, I haven't received a response regarding the ET number .
Just so that Volkswagen always uses the latest versions.

Does anyone happen to know if this part is compatible with my car's year of manufacture?

VW AG 05/0015
with part number 03L907807 T.
NOx emissions.
5WK96798
11/21/2013
Continental.

greetings

Postscript.

Otherwise, I checked the glow plug, and it has a resistance of 300 ohms, while the others have a resistance of 0.5 ohms.
Of course, my ten-gram glow plug nut is missing... just ordered a new one.

"My old Passat 3B with the ATJ engine had twice the mileage, and all the glow plugs were fine, except for the turbocharger cylinder head, which was okay."

Hello,

What funny things are you doing? Why don't you just read the part number from the old component, enter it into an online original parts service, and see if it says "replaced by..."?

Best regards, Rainer.

I know, I just checked again.

So, the latest number is...
03L907807AC
First came D.
After that came H.

Online, there is a version with the date November 21, 2013.
for just €150 and brand new.
Instead of AC for €490.

Can I install these? "350 more" is just a phrase.

Sure, here's the translation:

"Best regards," or "Sincerely," (depending on the context).

Chris.

Hi there!

I've now gotten the "D" version from a test car, and currently, the problem isn't happening anymore. I only replaced the glow plug.

In the OBD2 menu, under "Readiness," the oxygen sensor is still displayed in red after approximately 50 kilometers.
AGR was previously red, now it's green.
Does this mean the error is still present, but there's just no record of it in the error memory?

It's not that the probe isn't defective, and I'm going to replace it for free this weekend.

Regards,
Chris.

Small update.

Okay, in the MB1 readiness check, everything is green (except for the missing "Lambda" entry).
"Regarding the direct OBD2 reading, only the lambda sensor is showing a red value, which is normal. Is the NOx sensor not being classified as a lambda sensor?"

The NOx sensor didn't work as expected, but fortunately I can return it.

On this vacation trip, after driving 200 kilometers, the car immediately prompted me to check the AdBlue level.
The error was that the NOx effect was low, and then the sender 2 for NOx bank 1.

Instead of going abroad again, I prefer to come back home. On the way back, the "AdBlue check" warning disappeared after showing a remaining range of 500 km...

Take it to Volkswagen on Tuesday for safety's sake...
NOx sensor and complete test, possibly the injector.

If it's the pump again, and it's only been a year, then hopefully it would still be under warranty.
Having a problem like that abroad wouldn't be good.

Regards,

Chris.

Thank you for your feedback! After reading this, it seems that the current Audi with its AdBlue system is probably not a good fit for me.
It has already been proven that a simple oil pump drive is insufficient for my engine, so why would it be better with a chemical plant in the exhaust?

I would also say .
I'm not getting any more AdBlue delivered to my house...

The VW workshop called, as I suspected, and they couldn't find any errors at the moment.
The warning light for the AdBlue fluid level went out during the drive home...

And you only exchange parts without any certainty...

"I told them that I had experienced this intermittent error three times already."

The effect of NOX was weak on the third attempt.

They told me to drive it again until the problem reappears...

Great, I don't feel like it. Please check the AdBlue level again before reaching Austria. The lights indicate a remaining range of 1050 km...

I told them to replace the NOx sensor anyway.

Otherwise, it can't be anything else.

I'm thinking about going to the Shell gas station and completely filling up my AdBlue tank just to be safe.

Regards,

Chris.

And again, a call from the .
They checked the entire system and everything is okay.
They are now replacing the NOx sensor at my request, but without any guarantee that the problem won't reappear...
Then I'll get him back tomorrow...
We'll see...

Okay, I picked up the vehicle today.

NOX sensor replaced.
The 2 hours of troubleshooting will not be charged as a courtesy.
It would be great if all Volkswagen dealerships were like this one.
Okay, so there are no more errors stored in the MWB 1.

In the OBD2 fault memory.
Sure, here's the translation:

"For example, for TÜV (German technical inspection agency)."

Mode 03: Error related to exhaust emissions.
Address 7EB:1 - Error found.
P2BAD - Nox Exceedance: Cause unknown.
Mode 01, PID 01, Ready Status -- Address 7E8.

Number of stored errors: 1 -- Exhaust warning lights: Warning light OFF.

Lambda sensors failed.

Mode 07: Pending emissions-related errors: No error code found.

I can try to delete it, but the error in mode 03 persists.

I'm going to take the chance and go on that vacation trip again in a few days.
If the message reappears, drive for a while longer, then delete it and hope that after a few kilometers, the "AdBlue check" warning will disappear, and then my remaining range will be sufficient for the trip.

I just refilled the AdBlue.
I received one empty bottle from Volkswagen.
These were cut open at the back and used as funnels, allowing them to be completely filled directly from the fuel dispenser in the filling station.

61 cents per liter, 8.42 liters, 4.54 euros.
"Does this mean I can drive over 40,000 kilometers with a full AdBlue tank?"
At least something.

Best regards.

Edited by Guste100: Missing letters added at the author's request.