Samsung Gas Oven overheats giving error code C-21

Oven/Range/Cooktop Repair
1

Brand:Samsung
Model Number:NX60T8511SS/AA-02
Main Symptom:Oven Overheating
What happens & when: When I turn Bake on and set the temperature (350), the oven heats and does not stop at 350 it heats until it Overheats and gives error code C-21.

Error Code (if any):C-21
Parts or tests already tried: Changed out Temperature sensor.
Photos / video link:

2

If the igniter only turns on when the bake cycle is selected, the most likely issue is the sub-PCB in the console assembly AP7012789 if there is not a damaged wire. DG94-03575A Gas Range Control Panel Assembly | Genuine Samsung OEM In Stock

3

The igniter turns on with all options, I was just giving the example with the Bake option.

4

This indicates a failure in the main control board having a stuck L1 relay for the bake igniter. DG92-01207B Gas Range Main Control Board | Genuine Samsung OEM In Stock

5

Do I access it from the back?

6

Correct, it will be located on the back of the range.

7

Service Manual: