M59 will not drive

[MisterE]

Hey guys new member here. Got a m59 kubota that will not drive when I give it throttle. This morning, I started it then walked away to let it warm up and it died on its own. Came back and it wouldn't start. Said pto was engaged when it wasn't. Had to bypass the pto lever switch with a wire to get it to know pto was not engaged so I could start it. Now it will start, all hydraulics working fine. But will not drive. I'm lost. When you put it in gear; low
Medium or high; it apparently is in gear because I have it on a hill and it won't roll. Throw it in neutral and it rolls. But pus on the forward or reverse pedal and it does nothing. Crawl lever working too. Also pushing pedal does increase rpm. So to my thinking, throttle control works and it's engaging the gears. Why won't it go? Help!!!!

 

[Sysop]

From what I've read here and there, I'd say look at the linkages between the go-pedal and the HST. Many of these sorts of issues are something external.

What would worry me is the fact you had to bypass part of the electronics to get it to start. That makes me think perhaps the problem could be electrical in nature.

This may seem like a silly question, but how old is the battery in your unit? Family member of mine has a really high end JD, lots of sensors and all computer controlled; battery was starting to get weak, but not so much you would notice because it was spinning the engine fine. Power it up and everything would come on as it was supposed to. Twist the key to start and it would crank, but wouldn't put enough juice out to power all the sensors for a successful start. Didn't take much trying to start it to run the battery down where it wouldn't crank. Jumped it, fired right up. Disconnected the jumpers and all seemed well until the next time it was shut off. Would crank and crank with no start till killing the battery. Worst part was, it was finally taken to the local dealer to determine the issue. 3 day wait for an $80 battery and $125 labor...

Welcome to TBN, I hope your issue is resolved easily and inexpensively!

 

[MisterE]

Failed to mention it rained a lot! I keep thinking something might have got wet and shorted? But what would possibly cause it not to drive on e started and in gear?

 

[murphy1244]

Start with checking the Fuses.

 

[MisterE]

Hazard light fuse was out. Replaced that. No help

 

[MisterE]

So, does the m59 have a separate hydraulic pump for the transmission? And where is it located? Could there be some kind of electrical something that tells this pump to pump? Grasping at straws here. Got service manual on the way.

 

[TBarD]

The HST drive is a hydraulic pump coupled to a hydraulic motor, separate from the other tractor hydraulics (big pump on the right side, and a smaller one for the backhoe swing circuit). If the tractor moves fine with the creep lever while in first gear, then probably the HST drive is fine. I would be looking at the foot pedal and connections in that case. But it is odd that you would have problems with both the PTO sensor and foot pedal at the same time. If it is a moisture problem having to do with heavy rain, you might just want to wait a while.

 

[MisterE]

Doesn't move at all with creep lever or foot lever. Guess I was confusing in my earlier description. Was just stating that the creep lever does increase throttle.

 

[TBarD]

If it happens with both controls the foot pedal is not likely to be the problem. If it was working fine and just started doing this after a lot of rain then I would suspect some sort of electrical problem. I have never tried it myself, but I think you can put the console into some sort of diagnostic mode that might reveal useful information. When you get your service manual it should say how to do this and how to interpret the results. Someone mentioned checking the battery voltage; that is probably worthwhile as well since it is easy to do, although unless the battery is shot the voltage should not fluctuate enough to matter (should not drop below 10.5V or so, and that is only if it is fully depleted). Of course a loose connection could also cause problems. Another thing, when you first turn the key on, look for any messages on the console.

 

[MisterE]

Yeah. Sure wishing I had a service manual. Operators manual is of course worthless for this kind of stuff. Btw, it's a 2008 m59. I've had It in the shop a few times for other things and I
Sick of paying those shop fees. Dads an electrical engineer and if he had a wiring diagram we could possibly trace the problem.

My biggest question is this: whatin the world electrical would cause the tractor to not move when it's definitely in gear, throttle is worki g, and clutch is working (verified by operating the pto)??? Is there some kind of servo that actuates the pump in the transmission that could be haywire??

 

[TBarD]

Well you could actually have a HST problem, but the symptoms suggest it may be a simpler (and much less expensive) electrical problem instead, so that would be the first thing to look for. The ECU (computer) controls everything. The HST pump is directly connected to the engine via the clutch. Flow to the HST motor is controlled by a servomechanism that is controlled by the ECU. When you move the foot pedal the ECU is sending signals to the servo which moves a swash plate. The swash plate controls flow to the HST motor, providing forward or reverse and speed control, all by controlling the flow of hydraulic oil. The bottom line is, probably either the ECU is not saying go for some reason, or (less likely) you could conceivably have a problem with the HST servo. The first thing to do is check for error indications from the ECU, after which you would have to start running diagnostic tests.

 

[TBarD]

Be sure to check the console when you first turn the key, for any messages like ERROR-XX. The ECU checks a lot of sensors and should report any basic errors (and of course if its not happy, you aren't going anywhere or it might even turn off the engine!).

 

[BandDcabinet]

Auto throttle is a mechanical cable

Travel pedal sensor provides feed back to the ECU.

I would start there. Perhaps you will be lucky and find the connector loose.

Let me know if you would like further info..

Regards

 

[BandDcabinet]

Further diagnostic details. I have the elec schematic. In general it shows sensors attaching back to the ECU.

Regards

 

[MisterE]

Thanks tbard for the hst transmission explanation. I've been ignorant of how they work and that makes a lot of sense. Got a mechanic that's going to check it out thus evening. Its not giving me any error codes which I find strange.

Thanks band d cabinet for the electrical diagrams will definitely put them to use.

I'll be sure to let y'all know how it turns out.

 

[BandDcabinet]

One of the pictures walks you thru testing. Have you been holding down the two buttons when you switch it on?

 

[MisterE]

Btw, where is the ECU located?

 

[BandDcabinet]

See attached

I would run thru Test Mode A and check the feedback from various sensors. In particular T10 and T11.

Don't hesitate to ask for more info. My binder is 5 inches thick!!!



Regards.

 

[MisterE]

T10 and t11 check normal. T12 and t13 do not respond.

 

[ultrarunner]

Just a shot in the dark...

My Deere 110 did the same thing and I found a $60 sensor on the bell housing to be the problem...

It would start... just no movement with the pedal forward or back.

Relieved it was something simple and not expensive!