I suddenly have three lights come on. The ABS, hill assist and VDC lights are on solid yellow. I have had this happen a long time ago when I left the gas cap off but the check engine alight came on as well. I also had it come on the other day after I drove home from work with the low tire pressure warning on but it went out once I put air in the tires. Today there are no other lights. Anyone know what might cause these lights to be on without any other warning lights?