JLG boom lifts (450AJ, 600AJ, 800AJ, 460SJ, 660SJ, 860SJ, 1250AJP, M450AJ, M600JP)
JLG error code 776 — STALLED PUMP MOTOR OR POWER WIRING ERROR
Message on the display: STALLED PUMP MOTOR OR POWER WIRING ERROR · flash code 7/7
Code 776 occurs in machines: JLG M450AJ, E450AJ.
blocking fault
The power module pump MOSFET protection circuit is active, This is due to a massive current drain and could be a stalled pump motor or a power wiring error
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.
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.
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 Manuals: 600AJ (3121201), 800AJ (3120858), 460SJ, 860SJ, 1250AJP (3122581800), M450AJ (3121829), M600JP (3121711), Diagnostic Trouble Codes tables.
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 776 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.