GE Oven Error Code F91

F91 on a GE oven means the control board has detected a fault in the upper oven door latch switch circuit. The board cannot confirm whether the door latch is in the locked or unlocked position based on the signal it is receiving. This is most common after or during a self-clean cycle, since that is when the latch switch is actively monitored.

Start by checking the wiring and connectors at the door latch switch. On a T012 ERC, test continuity from Y pin 6 to BL pin 4 with the door closed and unlocked, and from Y pin 6 to O pin 5 with the door locked. On a Machine Control, check J900 pin 1 to pin 2. If continuity is missing, trace the harness for damage. If wiring is intact, test or replace the latch switch assembly. If both pass, the ERC or Machine Control board may need replacement.

A stuck locked door with F91 active points to the latch switch circuit preventing the control from commanding an unlock. First, cut power to the oven at the breaker for 30 seconds and restore it to see if the control resets and releases the latch. If it does not, you will need to check continuity on the latch switch circuit at the specified pins before the control will allow unlocking. Forcing the door open physically can damage the latch mechanism and should be avoided.

Normal baking and broiling may still be possible if the oven allows you to clear the code, but you should not attempt a self-clean cycle with F91 active. The latch circuit fault means the oven cannot reliably confirm door lock status, which is a safety requirement for self-clean operation. If the oven door is stuck locked and showing F91, do not force the door open; diagnose the latch switch circuit first.

If the fix is a wiring repair or connector reseat, the cost is primarily labor, typically one to two hours of a technician's time. A replacement door latch switch assembly generally runs between $30 and $80 for the part. If the ERC or Machine Control board is the cause, boards can range from $100 to $300 or more depending on the model. DIY repair is feasible for the wiring and latch switch steps, but board replacement requires confidence working with appliance electronics.