JLG boom lifts (450AJ, 600AJ, 800AJ, 460SJ, 660SJ, 860SJ, 1250AJP, M450AJ, M600JP)
JLG error code 00121 — RUNNING AT CREEP - CREEP SWITCH OPEN
Message on the display: RUNNING AT CREEP - CREEP SWITCH OPEN
Code 00121 occurs in machines: JLG 340AJ, 400S, 460SJ.
message
All function speeds are limited to creep because the creep switch is open.
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.
Solution from the manual
Turn Platform creep switch off
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 00121 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.