JLG ES series scissor lifts (1930ES, 2030ES, 2630ES, 2646ES, 3246ES)
JLG error code 251 — ELEV ANGLE SENSOR FAULTY - VOLTAGE OUT OF RANGE
Message on the display: ELEV ANGLE SENSOR FAULTY - VOLTAGE OUT OF RANGE
Code 251 occurs in machines: JLG ES series, 4045R, R4045.
blocking fault
The elevation angle sensor input voltage is outside the acceptable range of 0.10V - 4.50V.
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 that the platform elevation sensor is securely mounted and undamaged.
- Check voltage as displayed on ANALYZER -> DIAGNOSTICS -> ELEV SENSOR -> ANGLE SNSR. Backprobe ground board J1-15. If this voltage disagrees with the ANGLE SNSR voltage, replace the ground board.
- Backprobe the elevation angle sensor connector. Terminal A should be 4.7V, terminal C should be 0V.
- Check the elevation angle sensor signal and wiring to the ground board. The elevation angle sensor input is from ground board terminal J1-14 (4.7V), its output (0.1 - 1.2V when stowed) is to ground board terminal J1-15, and its ground is to ground board terminal J1-16.
- Replace the ground board.
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 251 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.