I think you should not worry yourself about what the problem is an certainly not attempt to fix the problem yourself as this could void warranty etc, i have two Toyotas and on the very rare occasion either of them develop a problem i take them to my local dealer. They have always been very friendly at the dealer and got the problem fixed very quickly. They usually even give your car a once over anyway just to make sure everything else is ok and they valet it as well. I hope this helps