edward is right partially (no offense edwardt) :o)

but we need to know what the display says in the error code log about which module it is erroring on.
There are more than one alarms for alarm 35.

access the alarm logs and scroll through them and check the last one logged, i'm sure there will be several logged though but pay attention to the hour meter time and date it was logged to get a more accurate idea of when these alarms took place.
The alarm log should show:
Alarm logbook: - 01 (or whatever position in the log it is at)
Code: XX (what the alarm code is)
Module: X (the module the alarm is being triggered from)
Date:
Time:
Hours:
Battery: (what the battery voltage percent is at the time of alarm)

depending on when the truck was mfg'd it could have either a zapi or an AC3 controller in it.
the zapi controller module number for mhyrio(hydraulic) is mod9
the AC3 controller module number for pump controller is mod37.

in any case though no matter which module the error is coming from it still deals with either an under/over voltage problem or a possible hardware issue from what i can see in each troubleshooting scenario for each code i've looked at.
Knowing the module number will get you on the right system :o)

the alarms history menu should show by pressing the enter button and then press the up or down buttons to scroll through the alarms.
the X button will exit out of the menus.