Remy Therrien

You may also check your 12 volt battery voltage. I have seen cases where the DC/DC converter (48Volt to 12Volt) stoped working and thus not charging the 12 volt battery anymore. I think the front differential electric shifter is powered by the 12 volt battery, that could explain the shifter not engaging if the battery is low. The 12volt battery is located under the driver seat. It powers the instrument panel + winch + main interlock relay on the 48V volt battery bank.

45C3 means that you probably have one or more batteries not holding their voltage above 6 volts. You can check each battery voltage with a multimeter, since they are connected in series.