Decelerator or Hand Throttle (STD cab) Position potentiometer voltage is too low
High range clutch is not calibrated
Aux 3rd Lower solenoid failed open or short circuit.
Low pressure switch (-) input shorted to power
Foot Throttle Position potentiometer voltage is too low (engine controller pin B30)
High range clutch is not calibrated
If Steering Not Working,Hydraulic suction filter plugged.Improper tire inflation.Steering linkage needs lubrication.Excessive play in steering. See your John Deere Dealer.