JLG ES series scissor lifts (1930ES, 2030ES, 2630ES, 2646ES, 3246ES)
JLG error code 256 — DRIVE PREVENTED - POTHOLE NOT ENGAGED
Message on the display: DRIVE PREVENTED - POTHOLE NOT ENGAGED
Code 256 occurs in machines: JLG ES series, 4045R, R4045.
blocking fault
Driving is not possible while elevated since the pot-hole protection system failed to deploy.
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
- Check for obstructions or mechanical problems around the pothole protection mechanisms.
- Check that the PHP switches are securely mounted.
- Adjust pot-hole protection switches.
- Check the pothole protection switches signal and wiring to the ground board. The left pot-hole protection switch input (24V) is from ground board terminal J1-9, and its output (24V when deployed) is to ground board terminal J1-10. The right pot-hole protection switch input (24V) is from ground board terminal J117, and its output (24V when deployed) is to ground board terminal J1-18.
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 256 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.