KitchenAid Over-the-Range Microwave Code F4E9: Smart Pop control or wiring flagged

What F4E9 means

On KitchenAid over-the-range microwave hood combinations like the KMHS120ESS, F4E9 refers to the Smart Pop control or its wiring. Smart Pop is the sensor-based popcorn feature. If the control or its connection misbehaves, the display shows F4E9 and the microwave may stop mid-program. Combination wall ovens use similar letters for an inverter instead. The popcorn key is the one you will notice stops responding.

Common causes of F4E9

Smart Pop control that is sending a bad signal
Loose or damaged wiring to the Smart Pop control

✓ One safe check you can try

1. Press Cancel and avoid the popcorn key for now. 2. Unplug the microwave or turn off its breaker for one minute, then restore power. 3. Run a simple timed cycle with a cup of water. 4. If F4E9 reappears, stop using the microwave and book a visit.

! Why to stop there

The control and wiring are behind the front panel of a wall-mounted microwave.
Removing the unit from the bracket is a two-person job and exposes live parts.
We give a written price first, and nothing is replaced on a hunch.

Opening a panel yourself does not automatically cancel a manufacturer warranty, but it can cause accidental damage, and some manufacturers set their own service conditions. Check your warranty terms, or ask us, before deciding.

→Same appliance

Other Microwave codes

Probe or Insert ProbeKitchenAid Combination Microwave Message "Probe" or "Insert Probe": Seat the meat probe in its jack PUSH or PSHKitchenAid Built-In Microwave Message PUSH or PSH: The oven is waiting for Start Registration ErrorKitchenAid Over-the-Range Microwave Message "Registration Error": Check the home network and try again Sabbath, Sab, 5Ab, or 5A6KitchenAid Built-In Microwave Display Sabbath, Sab, 5Ab or 5A6: Sabbath Mode is on SEKitchenAid Over-the-Range Microwave Code SE: Keypad or user interface problem F4 E3KitchenAid Combination Microwave Code F4 E3: Exhaust air temperature sensor F7 E9KitchenAid Over-the-Range Microwave Code F7 E9: Is the upper vent door blocked? Flashing Time, Clock, 12:00, Power Loss or Enter TimeKitchenAid Built-In Microwave Messages Time, 12:00 and Power Loss: Set the clock after an outage

F4E9F4E9 questions

Can I keep using normal cooking?

Often yes, as long as F4E9 stays off the display when you start a timed cycle. If it blocks everything, the microwave needs service. Normal timed cooking from the keypad is usually still available.

Do I have to avoid popcorn forever?

Only until the circuit is repaired. Use the timer for popcorn in the meantime and listen for pauses, because it is the Smart Pop control that has the problem.

Why does the code differ on a wall oven?

Combination microwave-wall ovens use F4 E9 for the inverter, a separate part. Check your model type before comparing information. Check your model type before comparing codes online.