JLG ES series scissor lifts (1930ES, 2030ES, 2630ES, 2646ES, 3246ES)
JLG error code 777 — OPEN CIRCUIT PUMP MOTOR WIRING
Message on the display: OPEN CIRCUIT PUMP MOTOR WIRING
Code 777 occurs in machines: JLG ES series, 1932RS, 6RS, 3248RS, 10RS.
blocking fault
Drive, Steer, and Lift Prevented
Description from the JLG service manual, in the original wording.
Possible causes
The manual does not list the causes for this code: the service technician establishes them during diagnosis of the machine.
Checks from the manual
- The System Module measured pump current less than 8A while the motor voltage was greater than 7V for 1200mS. This indicates there is an open-circuit between the System Module’s -P terminal and the pump motor.
- ZAPI - HEALTH (Status LED) - ON
What service does
A qualified service technician reads the code with the manufacturer's diagnostic tools, finds the cause, clears the code and carries out a function test.
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 777 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.