Air Quality Sensor 2012 Cali SE

[Richp]

Smoke and the smell of burning rubber through the front air vents on our 2012 Cali SE. Only stopped when engine battery disconnected. I guess it could be many things.. Any suggestions please. Seemed like if we had left the battery connected it could have gone up in smoke!

 

[Richp]

Has anyone had their air quality sensor burn out, producing smoke through the air vents?

 

[Kingfisher]

Has anyone had their air quality sensor burn out, producing smoke through the air vents?

Yes I did, on a then seven year old 2010 T5 SE. The burned plastic smoke coming through the vents completely negated any improvement of the interior air quality that the sensor may have offered over its lifetime.

I remember finding (here or on the German forum) that is was actually a common occurence, due to the sensor getting wet in the "box below the windscreen". Mine burned out after I used the windscreen washers while standing still, wiper fluid apparently causing the final short. The (rather expensive) sensor and the corresponding fuse had to replaced.

 

[Kingfisher]

I only now saw your previous post from July 11, about the smoke coming through the vents. I hope this did not happen with a car full of children at highway speeds. For me it was quite a disconcerting experience, like the van is on fire somewhere but you cannot find the flames

 

[Richp]

Thank you. That's rather helped put my mind at ease, as hearing your situation doubly confirmed that what's been diagnosed is the issue (and not a coincidental additional fault found during the diagnostics). We were travelling on a quiet road, with kids and dog, and able to stop immediately and evacuate as we really did think it was going to go up in smoke. You describe it perfectly. As for VW dealerships..... It was recovered to my local one, who said they could not even look to diagnose it for 2 to 3 weeks, and with a holiday in 10 days, I had it moved to a local electronics garage, family business, which, understanding our predicament, looked at it the evening of it's first day there, and diagnosed it, and fingers crossed we get it back Wednesday /Thursday, good to go, as soon as the part is delivered. Thanks for taking the time to comment on my post and, as I said, help put my mind at ease.

 

[Loz]

Also, check the fan speed resistor as that is also in the airflow

 

[Kingfisher]

Thank you. That's rather helped put my mind at ease, as hearing your situation doubly confirmed that what's been diagnosed is the issue (and not a coincidental additional fault found during the diagnostics). We were travelling on a quiet road, with kids and dog, and able to stop immediately and evacuate as we really did think it was going to go up in smoke. You describe it perfectly. As for VW dealerships..... It was recovered to my local one, who said they could not even look to diagnose it for 2 to 3 weeks, and with a holiday in 10 days, I had it moved to a local electronics garage, family business, which, understanding our predicament, looked at it the evening of it's first day there, and diagnosed it, and fingers crossed we get it back Wednesday /Thursday, good to go, as soon as the part is delivered. Thanks for taking the time to comment on my post and, as I said, help put my mind at ease.

You will be fine, it’s just a drop-in replacement of the sensor I think. Plus the diagnostics are hard to miss: the remains of the sensor will be quite obviously melted or burned.

One thing to check after picking up is that the climatronic still cools – this was somehow connected to the same fuse. I would also have the interior air filter replaced (some do it themselves), since that will now be saturated with rather unhealthy plastic smoke.

For me the new sensor behaved a bit more sensitive at first, switching to air recirculation mode frequently. This is apparently due to a ‘learning’ of the new sensor by the system. After that, things have been completely back to normal and I never had another problem.

Enjoy your holiday!

 

[KGCali]

You will be fine, it’s just a drop-in replacement of the sensor I think. Plus the diagnostics are hard to miss: the remains of the sensor will be quite obviously melted or burned.

One thing to check after picking up is that the climatronic still cools – this was somehow connected to the same fuse. I would also have the interior air filter replaced (some do it themselves), since that will now be saturated with rather unhealthy plastic smoke.

For me the new sensor behaved a bit more sensitive at first, switching to air recirculation mode frequently. This is apparently due to a ‘learning’ of the new sensor by the system. After that, things have been completely back to normal and I never had another problem.

Enjoy your holiday!

Do you have the part number of the air quality sensor?

 

[Kingfisher]

Do you have the part number of the air quality sensor?

I don’t have the part number for the sensor that was used in my van. The German caliboard.de forum does mention a part number: 7L0907643A. That was in 2009 however.

 

[KGCali]

I don’t have the part number for the sensor that was used in my van. The German caliboard.de forum does mention a part number: 7L0907643A. That was in 2009 however.

Thanks, yes that's similar to the part no I have and a Hella equivalent ...
Original VW 7E0907643 T5 T6 Transporter Air Quality Sensor G238
HELLA 6PX012684001 Air Quality Sensor
UPDATE...
Took out my air quality sensor today as I had an error on my OBDEleven scan stating it was short to ground and sure enough the pin was burnt out.
Anyone got a secondhand one, 7L0907643A?

 

[KGCali]

Thanks, yes that's similar to the part no I have and a Hella equivalent ...
Original VW 7E0907643 T5 T6 Transporter Air Quality Sensor G238
HELLA 6PX012684001 Air Quality Sensor
UPDATE...
Took out my air quality sensor today as I had an error on my OBDEleven scan stating it was short to ground and sure enough the pin was burnt out.
Anyone got a secondhand one, 7L0907643A?

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UPDATE - SOLVED ... I couldn't find a used VW Air Quality Sensor 7L0907643A and a genuine one is about £100 so I researched a little and found compatible genuine VW, Audi, Skoda part numbers then searched used parts on eBay.
I purchased Audi part number 4B0907659A for about £15 delivered, fitted it today and all working fine now