The problem can be a bad oven shutdown fuse (on the back of the oven) or a bad DLB relay (behind the control panel on the right side).
The oven shutdown fuse can be tested from the front after you will open the control panel. Check for continuity between wires connected to the P2-4 (R) or P3-1 (OR) terminals at the control board and the R/W wire at the DLB relay.
If the circuit is open, replace the oven shutdown fuse.
Otherwise replace the DLB relay.
- The thermal shutdown fuse Part number: 9759243
- The DLB relay Part number: 9752759
Here are the breakdown diagrams and Parts for Whirlpool GSC309PVS02 Wall Oven - AppliancePartsPros.com