The "E1" error code means the thermistor is open but it could be also a broken wire, loose connections at the teamster and/or the control board and a bad control board.
The first thing I would do is run the test #3a as described in the
tech sheets, check all wires and , if there is nothing wrong, replace the control board.
Here are the break down diagrams for the Whirlpool dryer
Model GEW9200LW0
Gene.