JayDee4711

Thanks for posting the update! Good for you that it hasn't reappeared in a while. I doubt, however, that there is a causal connection to cleaning your steering wheel. Or if there is, that it is the only one. Traffic jam assist is only available if a number of factors coincide: Speed below threshold X, camera detects lane markers (see @Scotty (UK) 's comment), camera detects a certain number of vehicles traveling equally slowly in front of you, ACC is active (i.e., set to a particular speed, not only enabled), and possibly a few more conditions. If any condition is not met, traffic jam assist is not available, but the car won't tell you all the time, as that would be a constant flurry of the same error message, AKA noise. If you then take your hands off the wheel, traffic jam assist becomes _active_. If then one of the necessary conditions is no longer met, the car will tell you to take over steering. And if you don't, it will eventually hit the brakes. It won't tell you that traffic jam assist is not available.

If the car tells you that the function is not available, that would be because one of the sensors required for the function is not available. That could be the forward-facing camera(s), as others mentioned, the radar sensor for the ACC, or probably a number of other components involved in sensory input. Including, now that I think about it some more, the capacitive sensor that tells the car whether or not you have a hand on the wheel. And that is precisely where the causal connection could actually be! If the car, in whichever way, determines that the steering wheel touch sensor isn't working, it would most likely also give you that warning. And if cleaning the leather re-enables the sensor, that could explain your observation. So please ignore my babble above, and let's hope that that is actually what was going on.

And yes, I am 100% with you on the dealer just trying to *** you off with a bunch of suck-it-up BS. That's how dealers very efficiently make me an ex-customer...

Wires

Unless something changed in 2021 with them using better hand detection, the previous cars just sense the wheel jiggling as "you have hands on the wheel". Hence the boat load of false positives when you use lane assist and are driving on a straight road.

atlanta A6

this is a super comprehensive write up and not at all babble. Thank you for the additional details and thoughts

JayDee4711

I don’t know what model year it was introduced, but mine definitely detects touching the wheel without any wiggling. Those exact warnings were one of the things I didn’t like about the Accord I had previously. So I purposely tried this a number of times while using traffic jam assist: When the car tells me to take over, putting a finger or two on the rim without moving it in the slightest makes that warning go away.

I am sure that jiggling would also be interpreted as hands on the wheel. So let me dare a hypothesis: It is possible that your capacitive sensor isn’t working well, but your car doesn’t detect it as unavailable. It might be worth trying leather cleaner.

SMac770

The capacitive touch "hands-on detection" steering wheel was introduced MY21 in the US B9 products. Being capacitive, any dirt or gloves or such are going to impact that reading. None of the measuring values for 16 or A5 seem to stand out as "hand detection value". There's probably something somewhere to confirm the hand detection action, but don't have a MY21+ to explore.

Elvisfan

I’ve never had the car tell me to put my hands on the wheel. Except the time I actually tested it. Now on my Mercedes, it’s telling me several times if I have the CC on.

JayDee4711

Thanks for the clarification, @SMac770 !
Same here: Never a false alarm. The car only ever tells me to take over when I actually don't have my hands on the wheel.