In my Soul, it kicked in when one of them dropped to 31. When I picked my car up, I had already had the tyres changed and they looked a little low, so it was on my to-do list to take it round to the garage and check them. The following morning, the TPMS kicked in anyway and told me the front left was reading 31. I inflated them all back to 36, according to the garage air line, and the TPMS read them as 35.Does anyone know at what pressure the TPMS gets upset? I couldn’t find any settings to adjust the limits. Maybe it’s hidden somewhere? Or maybe it just looks for excessive difference between the four pressures?