Low pressure switch open for cumulative 60 seconds (no consecutive requirement)
Decelerator (STD cab) Position potentiometer voltage is too low
Master clutch is not calibrated
Aux 3rd Raise solenoid failed open or short circuit.
Low pressure switch open for > 1 minute
Master clutch is not calibrated
If Inadequate air flow is problematic, so clogged air filters, evaporator core air flow restricted, faulty blower fan motors, defective blower switch or faulty wiring or loose connections.