Its been a long winter, and finally found a great weekend to fire up the smoker - and got the dreaded E1 error. Had to do a little troubleshooting, confirmed the sensor cable was good - and measured the resistance on the sensor - and noticed the sensor measured opened at the connector jack.
So - pulled off the back metal plate of the unit, and found the center pin on the back side of the plug unit had broken off somehow. I attempted to repair the plug unit, and opted to simply solder a longer extension cable and connector to effectively replace the sensor cable.
This fixed the E1 error.
Foodog