Kubota M120 three point hitch problems

[zegersfarm]

Our Kubota M120 has a problem with the 3 point hitch. Sometimes the 3 point hitch works ok, but most it goes in "Lock" and neither cab controls or fender controls work. The 3ph height sensor and the draft sensor have been replaced but no difference.
We worked through the WSM and all electrical measurements are close to the WSM specs.
If I rev (spike) up the engine to 1000 RPM the yellow 3ph light and the green draft control light flash fast or slow for a few seconds, than only the yellow 3ph light flash for some seconds.
Rev it up again and the same.

(I think the cab 3ph controls and the 3ph controller have been replaced before we got the tractor.)
2421 hrs , filters are serviced according to maintenance schedule. Hydraulic oil is CASE Hy-tran.

Any idees anyone?

 

[Harry in Ky]

Only that it's probably time to get a Kubota computer tech involved. Whatever that takes. The issue is probably out of reach for most of us common folk.

 

[zegersfarm]

This tractor does not have on board diagnostics. First thing the Kubota tech did was look for the diagnostics connector, when there wasn't one he told us to bring the tractor to the shop.

 

[Harry in Ky]

Connector or no connector, it's still a Kubota tech "whatever it takes" issue. What else is left? You've covered all the simple bases with no real results. It's one of the joys of owning computer controlled equipment.

 

[Kubota Red]

This may or may not help. If you move the 3 point lever in the cab with the tractor off, it confuses the tractor. Example: If you lower the implement and shut the tractor off, then move the lever in the cab to the "raised" position (and leave it there), when you restart the tractor, the ECU sees that the arms are lowered, but the lever is in the raised position and it recognizes something is wrong (and prevents the 3 point from moving). The fix this, all you have to do is move the lever in the cab all the way up and all the way down. When you do this, at some point in the movement the ECU will see the arm and lever location match up and it will begin to work normally again.

This may not be the issue you are having, but thought it might be worth a shot.

PS It has been awhile since I have dealt with this issue, so my memory on the exact detail may be a bit off. But basically, when you have the issue, move the lever the full stroke up and down and see if it makes any difference. Doubt it is this simple, but hopefully it is.

 

[OStebbins]

Sounds like you’ve done a lot of troubleshooting already. You might want to check the hydraulic pressure or the valve assembly, as sometimes they can act up even if everything else seems fine. Also, online marketplace app development services could be useful if you're looking into more tailored solutions for this issue.