4804A is tied to the Menu P04 'Alarm Menu', item# 1 'Service timer'.

Service Countdown Timer:

The service countdown timer will count down from the set value in accordance with running hours. When the item is viewed the service hour’s value will reflect the current hours remaining until a routine maintenance service is due (zero hours). When zero hours are reached a service due alarm will be displayed.

The alarm can only be reset when the service hours is adjusted above zero. The service hours count will continue to count down in negative values until the timer is re-set.

This function is intended to promote timely routine maintenance and indicate how many running hours have passed since a service due alarm was displayed. The value can be  adjusted back to the required maintenance interval time each time a maintenance service is completed.

Follow the next steps to reset the error 4804A service hours time expired.
1) Error 4804A is active.

2) Go to P04 = alarm menu of controller.

3) In P04 check which SD service timer = 0 or is negative and press ENTER.

4) Set Timer back to desired time ( For example 2000 ) and press ENTER.

5) Go back to home screen by pushing the ESCAPE button.

6) When you are on the home screen push the RESET button and the error 4804A will disappear.