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this error mean the oven has overheated at some point and the sensor may be bad.
1. (F10 only) Check *RTD Sensor Probe & replace if necessary. If oven is overheating, disconnect power. If oven continues to overheat when the power is reapplied, replace EOC. Severe overheating may require the entire oven to be replaced should damage be extensive.
this is the sensor, if you click this link and it shows you how to test it, http://www.repairclinic.com/PartDetail/Temperature-Sensor/1015027?modelNumber=FEB27S6DSA#repairHelpVideoTabs you will need a voltmeter to do this, hope this helps, thanks Bryan