Check the loading door of the Kenmore dryer to ensure it is fully closed. Make sure clothing was not caught in the door during closing. This may keep the door ajar enough to prevent the activation of the door safety switch.
Check the power cord plug to ensure it is fully inserted into the electrical receptacle at the rear of the appliance.
Check the circuit breaker at the main house panel. If the breaker assigned to the dryer has been tripped, reset the breaker by turning it to the "Off" position first, then to the "On" position.
Reset the dryer to correct the PF error code and resume drying by depressing the "Start" button and holding it for 5 seconds.