NOx sensor fault

[Grim Reaper]

I think a week after buying it I would be returning it to the dealer with a 'Fix it or else' message attached to a brick.

 

[kernowcoles]

That drastic! Reading through a few similar threads looks like some have just cleared the fault and carried on.

I'm not actually getting an EML on the dash which I think is why the local VW van centre aren't being particularly helpful.

Obviously want to get it sorted while under warranty though if it's covered.

 

[mmi]

That drastic! Reading through a few similar threads looks like some have just cleared the fault and carried on.

I'm not actually getting an EML on the dash which I think is why the local VW van centre aren't being particularly helpful.

Obviously want to get it sorted while under warranty though if it's covered.

Did the faults occur during your ownership or are they older ones = was the fault memory clear on day one?
Please post "Detailed ECU info"-report (under Carista Service menu).

 

[kernowcoles]

Did the faults occur during your ownership or are they older ones = was the fault memory clear on day one?
Please post "Detailed ECU info"-report (under Carista Service menu).

Will plug Carista back in tomorrow and post screen grab of Detailed ECU info. Good point as I never thought to check when the faults first appeared (before or after I bought the van).
Travelled 300 miles from Cornwall to St Albans to buy it so will be might miffed if they've sold it to me with this fault

 

[kernowcoles]

Did the faults occur during your ownership or are they older ones = was the fault memory clear on day one?
Please post "Detailed ECU info"-report (under Carista Service menu).

Looks like there might be an issue with the time/date on the ECU - saying the faults occurred in 2059!

33262 –

Freeze frame

Priority: 2

Malfunction frequency counter: 2

Unlearning counter: 255

Odometer reading: 64104 km

Date: 12 Jan 2059 01:40:50 pm

Engine rpm: 1890.25 RPM

Normed load value: 22.0 %

Vehicle speed: 108.0 km/h

Coolant temperature: 90 °C

Intake air temperature: 12 °C

Ambient air pressure: 1030 mbar

Voltage terminal 30: 12.804 V

‐-----------------
31103 –

Freeze frame

Priority: 2

Malfunction frequency counter: 5

Unlearning counter: 255

Odometer reading: 64028 km

Date: 12 Jan 2059 12:35:49 pm

Engine rpm: 1916.00 RPM

Normed load value: 51.8 %

Vehicle speed: 108.0 km/h

Coolant temperature: 90 °C

Intake air temperature: 10 °C

Ambient air pressure: 1020 mbar

Voltage terminal 30: 12.632 V

 

[DXX]

Check the T&C’s of your contract. I think you will find that you are entitled to reject the van after 1 week of ownership. This may have some bearing on whether they will want to charge for diagnostics!

 

[Grim Reaper]

Yeah, I noticed that, but is there any way to correct it? It might be that the netbook I use to connect to the VCDS has no battery backup for its date & time and it always needs resetting. I might have a look later.

 

[mmi]

Looks like there might be an issue with the time/date on the ECU - saying the faults occurred in 2059!

The date decoding is VCDS issue - for this particular ECU.
However, the odometer reading and the time are correct. They are from the first incident.

 

[kernowcoles]

The date decoding is VCDS issue - for this particular ECU.
However, the odometer reading and the time are correct. They are from the first incident.

Silly question but is there a way to truly find out when the faults first occurred in that case?

Update is that the VW van centre I bought the van from have confirmed tge fault can be sorted under warranty and that the £125 diagnostic fee will be waived. They did mention that this fault can be intermittent and that if it doesn't show up when the scan it themselves l, they won't help me at all.

 

[mmi]

Silly question but is there a way to truly find out when the faults first occurred in that case?

VW diagnostic tool (ODIS) decodes the dates correctly. The recorded odometer reading should help, too?

They did mention that this fault can be intermittent and that if it doesn't show up when the scan it themselves l, they won't help me at all.

(Many of) the ECU faults "fade away" in approx. 300 miles if the fault won't resurface. E.g. P20EE is one of those.

 

[kernowcoles]

Thanks so much for the support and advice.

One more queation - does the fact that I have no EML light on the dash, despite the fault showing up on Carista, mean anything in terms of how severe the problem is/how likely it is that it will just "fade away"?

 

[mmi]

One more queation - does the fact that I have no EML light on the dash, despite the fault showing up on Carista, mean anything in terms of how severe the problem is/how likely it is that it will just "fade away"?

No EML light just means that some longer term threshold has not been reached.

Based on my observations the ECU seems to record "faults/events" quite easily but also fade them fairly soon if they don't reappear. Thus impossible to say how severe they are based solely on this information.

However, e.g. VCDS extracts some extra bits of information - fault frequency - which tells how often a fault has been captured.

A clarification about "fade away" - it means that e.g VW ODIS doesn't recognise those any more. Perhaps better word to describe would be "archived" because e.g. VCDS still can read these fault records - till they are explicitly cleared.