I have a JD 310SG, that is acting weird. It is showing hot on the emp. gauge, but is not running hot. It shows a code of F450. When started cold, it runs for just a few minutes, then the needle starts to rise. It climbs to the hot side, and shows F450. When disconnected, the needle stays on the cold side, and when connected, it seems to climb with the more RPM's, until it pegs out and shows the code of F450. I have changed the water sending sensor, the operating solenoid in the dash. I have checked the ground on the frame where a lot of wires are grounded. Has anyone else experienced this type of problem with this type of machine?
I don't know this machine and not trying to insult your intelligence but, Have you measured the impedance on the new sensor and the old one ? Checked the fluid level ? Do you know if it's a wet bulb or a dry bulb type sensor ? Is the water pump working ? Good luck to you.
Checked temp with non contact thermometer? Gauge ok?
The only way to get an F450 coolant temp sensor input voltage at 0 volts is to have a short in the signal wire (X07 Yellow wire) to ground or a bad ecu.
Provided the sensor is not internally shorted.
RGraham, I have a JD 310SG that is doing the exact same thing. Did you figure out what was happening with yours? What I'm seeing is after a few minutes of warm up the temp gauge begins to climb to the top. Coolant in the radiator is warm, not hot. I can take off the cap and put my finger in it. But gauge shows very hot. Levels seem right. I haven't done anything yet, but am figuring on replacing thermostat and sensor. I kind of suspect the sensor since it runs fine doesn't seem to be overheating, although of course I haven't run it long. What do you think? rScotty
Well, I got it fixed and thought I'd share the results so as to help anyone else with the F450 error code and erratic gauge readouts. It always ran fine, but eventually the temperature gauge would climb to max immediately upon starting the backhoe. That's when I knew something was wrong. I changed the thermostat sensor (old one was OK), checked the thermostat operation with a thermometer (opens at 180F), and then traced all the wiring for bad connections & shorts. The standard procedure for resetting the error code wasn't working on my dash readout either. Went to talk to JD dealer and they said it was probably the engine controller. They saw it a lot on SGs that have the engine controller in the engine compartment where it gets vibration, heat soak, and fluids.....but never at all in machines that had the engine controller in the cab as later models had them. It is roughly a $1600 part & a charge to re-program the new one for my machine. There is also said to be a wiring harness that allows the new engine controller to be moved into the cab where it is on newer model 310s. So I figured I'd consider doing that until I found out that the harness to move the controller costs as much as a new controller does. it is the same price as the controller all over again. BTW, the engine controller also controls the injectors....but that function seemed to be working fine on mine. The only obvious symptom was the F450 error code that couldn't be erased and strange temperature gauge readings. So I went home and disconnected the engine controller, cleaned all the terminals, checked the wiring again, and reinstalled it. Everything worked fine for about ten minutes and then the gauges went wonky again. I elected to have the service truck come out and replace the controller. It's an upgrade; the old one is worth a $200 core charge. Replaced the main hydraulic suction hose at the same time and new JD trans/hyd. fluid. Bill just short of $3K. Everything works like new again and the panel readout in the cab is working normally. rScotty
I seem to be having the same issues. not starting and stalling or misfiring. Good fuel but it was the wire coming to the fuel solenoid. I could wiggle the wires and get it running. So tried to check conduction of the wires and all good with no change on bending or moving the wires. If I push on the wire at the connector it would run fine. Changed the connector on the challenging wire but I’m starting to think there is a short inside the ecu where the pin goes inside. Guess it will be the service call again to replace. At least I got the loader up into service position before doing this work.
The wire could be broken inside the insulation and not visible. I have seen that happen several times. Once it was the starter switch to solenoid and I had to replace the entire wire because it was inside a loom.
it runs fine if i put pressure at the connector end to the ecu. Opened up the loom all the way back to the fuel solenoid. It only changes from running to not running with movement at the ECU pin. I’ve also had a couple other codes from another section of the ecu harness. This is why I’m thinking it’s ecu as it’s putting more codes including the new F9C4 which can be ECU. Too many things pointing back to the ecu.