Bosch range oven displays F3 and will not start a bake or broil cycle.

Safety first: Disconnect power before removing the oven's rear panel or accessing the sensor.

• Inspect sensor: Locate the oven temperature sensor inside the oven cavity (usually back wall). Remove the mounting screws and gently pull the sensor forward to access the connector.
• Check continuity: Disconnect the sensor and test for continuity with a multimeter. Replace if open.
• Check harness: If the sensor tests good, inspect the wiring from the sensor to the control board for breaks or burns.
• Repair or replace: Repair damaged wiring or replace the sensor harness. If wiring is intact, the control board may be misreading and require replacement.