My mom has a 2004 Escape. Every time she drives it the car makes a 'ding' sound as if the seatbelt is not latched or a door is open. This sound goes in a series of 'dinging' 5 times in a row, pause, and five more times in a row. this repeats for a total of 5 series of 5 'dings' then goes away, but comes back anywhere from 20-30 minutes later. No lights come on in the dash and I can't find any other indication as to what it is. The parts store couldn't get a code to come up when he tried. Has anyone else had this issue or suggestions before have her take it to the dealer?