Diagnosis
Your range lost power. PF means Power Failure. It's a lockout state after a power flicker or outage.
How to Fix It
Unplug the range from the wall outlet. Wait one full minute. Plug it firmly back in. The PF code should clear. The clock will need resetting.
If That Didn't Work
The power cord connection at the terminal block behind the range might be loose. Unplug it. Remove the rear access panel. Check all three wires (black, red, white) are tight on the L1, L2, and Neutral terminals. Tighten if needed.
Heads Up
Do not just press buttons to clear PF. A hard power cycle is required. If PF returns without a power outage, have your outlet and home wiring checked.