Any ideas how the system knows if one's hands are on the wheel? When I get the message saying to put my hands on the wheel sometimes just lightly touching the wheel with one hand works. But sometimes I have to grip the wheel hard. And other times I need to move the wheel slightly. All of the preceding with gloved and bare hands. Also, anyone noticed lately the "Put hands on wheel" message is not always accompanied by a chime? Ignore the message and eventually the chime sounds but seems like in the past a chime always sounded when the message appeared.