The air quality sensor (1K0907659) appears to have failed on our 2013 Yeti. In VCDS it is throwing the DTC 9481988 - Air Quality Sensor B10AF 04 [008] - Internal System Fault

The price of a replacement OEM part was £140 plus the hassle of a 1 hour round trip to collect it from the dealer. So given the price of £20 for a Chinese version, I have tried that. However it is giving me a different fault 9479189 - Signal Line for Air Quality Sensor B10A4 15 [008] - Open or Short to Plus Upon testing this Chinese part on a bench using a PSU set to 12V 0.1A, with pin 1 (12V), pin 2 GND, then I'm seeing 10.5V on pin 3 for a few seconds and then it drops to 9.5V for the remaining time. It is drawing 45mA and then 0mA respectively. I think it is simply a fault part but curious to know how others have got on with the Chinese part? Has anybody got voltage & current values for a known good sensor? The old failed sensor I have has 0.5V on pin 3 and is drawing about 10mA constantly.

Edited 5 hours ago5 hr by rabbituk

I believe there are two different styles of sensor around this time, one with an output that is at a low voltage when measured with a meter, the other with an output that sits high as measured with a multimeter. You may have the wrong type. The latter, later type is the LIN-based one, I think, but would need your VIN to research which type your car should have.

See G65 sensor no signal - Skoda Octavia Mk3 (2013 - 2020) - BRISKODA

I'll message you to ask for the VIN. Is there no letter suffix after the core 1K0907659 part number you mentioned.?

Those suffix letters can identify/disambiguate completely incompatible versions.

Edited 3 hours ago3 hr by Breezy_Pete

Unfortunately, there is no postfix to the part number. Other writing on the older failed unit is 'PAG', the end opposite the sense intake has 'IND 12' and 'II 232/32'. Presumably the latter being a part manufacture date.

That turns out to be consistent with the parts catalogue. For your VIN, the number you quoted is complete without any suffix.

It has been superseded by 5K0 907 659, but that's not the key point.

Circuit diagrams for your date of manufacture (28.08.13) show no sign of the output being a LIN bus signal.

Searching through Yeti circuit diagrams that I have, as far as mid-2016 still don't show a LIN output version air quality sensor, so I suspect that this model never changed over, unlike in that thread I linked above.

I suspect the item you've bought suits LIN-based air quality sensor systems instead.

Try to match your exact part number, or the superseding one above, and ignore any that have suffixes after the main 9 characters.

Try buying a genuine one from TPS, they usually deliver as well when you set up an account.

36 minutes ago, Breezy_Pete said:

That turns out to be consistent with the parts catalogue. For your VIN, the number you quoted is complete without any suffix.

It has been superseded by 5K0 907 659, but that's not the key point.

Circuit diagrams for your date of manufacture (28.08.13) show no sign of the output being a LIN bus signal.

Searching through Yeti circuit diagrams that I have, as far as mid-2016 still don't show a LIN output version air quality sensor, so I suspect that this model never changed over, unlike in that thread I linked above.

I suspect the item you've bought suits LIN-based air quality sensor systems instead.

Try to match your exact part number, or the superseding one above, and ignore any that have suffixes after the main 9 characters.

I don't have a 'scope that I can use to test this part with however I don't see much movement in the value which I would likely see if the value was oscillating over time. Presumably we can't know if the superseded part was an improvement or simply a change of sub manufacturer.

The eBay advert I purchased it from specifically listed my car model as well as the aforementioned OE part number so I thought it would be the correct type. For a non-safety critical part like this I was just trying to see if I could save a little money.