Lennox Equipment not specified Error Code 9

Screen Text: no external sensor. Priority: 1 (middle). Message Type: critical. Condition: The outdoor temperature sensor is out of range (-50°F to 180°F). System Action: For Outdoor Temperature Sensor: No Humiditrol or Humidity operation. D terminal stays activated and other operation will continue to operate. Thermostat will stop the system operation if input from requires outdoor temperature information when any of these conditions, i.e. balance point control and 2nd stage lock in are applicable. System will default to mode of operation that does not required input from the outdoor temperature sensor. The temperature display on the home screen will be disabled. If user turns on the display from user settings and error will be displayed again. This error is displayed in notification screen.