JLG 1250AJP Service Manual - Manual (Page 190)

SECTION 3 - 1CHASSIS & TURNTABLE
3-142 – JLG Lift – 3121171
Does DST display ECT
voltage of 4.9 VDC or
greater?
· Key Off
· Disconnect ECT sensor from harness
· Key On, Engine Off
· System Mode = “Stopped”
· Sensor signal circuit shorted to ground,
check wire harness for ground short
· Faulty ECM
· Faulty ECT
Sensor
Yes
No
Does DST display an ECT
voltage less the limit
defined in calibration?
· Intermittent Problem
Yes
No
· Key On, Engine Running
· System Mode = “Running”