Hi. Welcome to JustAnswer.
What is the model number of the unit, please?
Looking at the service manual for the CMT series of ovens I am not showing any error codes. Of course I can not search it as it is photo copied to .pdf. Please stand by. I am still looking through the manual.
Does your unit have the micro included? Single or double oven?
Turn the power off at the breaker panel if it is hard wired to the system. Otherwise there should be an outlet directly above the unit to plug it into. Just unplug it if that is the case.
Would you like a copy of the service manual?