GE Range Error Code F621

F621 indicates a LIN communication error between the Main Control Board and the RPSM Auxiliary Board. LIN is a serial data protocol the boards use to coordinate operation. This code only appears on GE ranges equipped with the RPSM Aux Board. The fault typically points to a failed Aux Board or a wiring issue between the two boards.

The F621 code is a communication fault rather than an immediate fire or safety hazard. However, the Aux Board failure may affect certain range functions or cause unpredictable operation. It is best to limit use of the appliance until the fault is diagnosed and repaired to avoid potential secondary issues.

Repair costs depend on whether the fix is a wiring correction or a board replacement. If only connector cleaning or harness repair is needed, costs may be relatively low, primarily covering labor. If the Aux Board requires replacement, parts plus labor can range from around $150 to $400 or more depending on the specific model and service rates in your area.

If you are comfortable working with appliance electronics, you can inspect the wiring harness and connectors between the Main Board and Aux Board for loose or damaged connections. However, if the wiring appears intact, the Aux Board will likely need to be replaced, which requires identifying the correct part and safely accessing the range's control area. Many homeowners prefer to have a qualified technician handle board-level repairs.

Resetting the range by disconnecting power for a few minutes may temporarily clear the F621 code, but it will return if the underlying communication fault is not resolved. The Aux Board or wiring issue causing the fault must be addressed for the code to stay cleared.