I believe you are correct.
Your model uses Door Lock Motor and Switch Assembly Part # 316464300
It's located at the back of the range. If you click on the part number link I posted above you will find a help video for that part.
I have replaced a number of these on Frigidaire ranges in the last few years, can't recall just what the error code was off hand, but it does seem to be a common problem.
You could check the motor with a ohm meter. You could also check to see if voltage is getting to the motor when you try to self clean. If there is voltage getting to the motor, but the motor does not turn to lock the oven door then the door lock motor is bad for sure.