I have a 2003 John Deere 310G 4WD backhoe throwing an intermittent fault code F421. Can any JD expert out there tell me what this code means? There is no outward problem that is exhibited and everything except for the fault code seems normal.
I am far from a JD expert, but since you have not gotten any replies to your question, let me offer this. I don’t have a 310G technical manual, but the 310SG manual says a F421 is ”Throttle Input Voltage Below Lower Calibration Limit”. There are various calibration and adjustment procedures listed based on serial number of tractor. These procedures are about 4 pages and involve the use of a multi-meter and other tools to access & adjust the sensor. Perhaps you could visit a JD dealer with your 310G serial number and get the correct procedure for your unit. I hope this helps.
Thanks for the input. I've been putting off spending the $$$ for the manual. Looks like JD technical pubs. will be getting an order soon.