DT*: THE CONTACT STATED WHILE PARKED AND RUNNING WITH THE SEAT BELT UNBUCKLED, THE HEATER WAS TURNED ON FOR THE PASSENGER SEAT AND WITHIN 10 TO 15 SECONDS, THE SEAT CAUGHT ON FIRE. THE HEATER WAS TURNED OFF, AND BOTH OCCUPANTS SUSTAINED MINOR INJURIES. THE SERVICE DEALER WAS CONTACTED, BUT COULD NOT IDENTIFY THE PROBLEM.