JLG boom lifts (450AJ, 600AJ, 800AJ, 460SJ, 660SJ, 860SJ, 1250AJP, M450AJ, M600JP)
JLG error code 237 — START SWITCH LOCKED - SELECTED BEFORE KEYSWITCH
Message on the display: START SWITCH LOCKED - SELECTED BEFORE KEYSWITCH · flash code 2/3
Code 237 occurs in machines: JLG 860SJ, 800S, 600AJ, 600S, 660SJ, 800AJ, 800A, 460SJ, 400S, 1250AJP, 1100S, 1100SJP, 340AJ, 600SC, 600SJC, 660SJC.
blocking fault
The Start Switch was closed during powerup.
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 UGM shall prohibit Engine Start.
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 237 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.
Neighbouring JLG codes
- 234FUNCTION SWITCHES FAULTY - CHECK DIAGNOSTICS/BOOM
- 235FUNCTION SWITCHES LOCKED - SELECTED BEFORE AUX POWER
- 236FUNCTION SWITCHES LOCKED - SELECTED BEFORE START SWITCH
- 241AMBIENT TEMPERATURE SENSOR - OUT OF RANGE LOW
- 242AMBIENT TEMPERATURE SENSOR - OUT OF RANGE HIGH
- 253DRIVE PREVENTED - CHARGER CONNECTED