JLG ES series scissor lifts (1930ES, 2030ES, 2630ES, 2646ES, 3246ES)
JLG error code 4477 — BATTERY VOLTAGE TOO HIGH - FORCING DISCHARGE
Message on the display: BATTERY VOLTAGE TOO HIGH - FORCING DISCHARGE
Code 4477 occurs in machines: JLG 4045R, R4045.
blocking fault
The JLG display shows code 4477 with the message “BATTERY VOLTAGE TOO HIGH - FORCING DISCHARGE”. It is a blocking fault or a safety-related code: do not use the machine until the cause has been found and removed.
Possible causes
The manual does not list the causes for this code: the service technician establishes them during diagnosis of the machine.
What you can do
Switch the machine off with the emergency stop and switch it on again. If the code comes back, do not use the machine and call service.
Solution from the manual
Disable VSW, Lift Down State = PREVENTED Lift Up State = PREVENTED Drive State = PREVENTED suppress other system errors, then Energize STEER R VLV _ _ and STEER L VLV and moni_ _ tor VBAT
Source: JLG Service and Maintenance Manual, ES series (Diagnostic Trouble Codes section).
The descriptions are quoted from the manufacturer's service documentation and are for guidance only. Clearing codes, calibrations and repairs are carried out by a qualified service technician according to the manual for the specific serial number. A machine with an active blocking code must not be used until the cause has been removed.
Does code 4477 not go away?
RK Rental services JLG lifts at our workshop or on site at the customer's premises (construction site, factory, warehouse). We read the code, remove the cause and select the parts by serial number.