L3901 died instantly an and now giving error coded E-20

Timmer92

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Equipment
2019 L3901 (former - BX2370), 72" Brush Hog, 72" Hydraulic Snow Blade, 3pt Auger
Dec 4, 2019
121
15
18
Minnesota
Hi all,

I have a 2019 L3901. I had been using my tractor to haul wood and brush for an hour or so. I was in the middle of crushing down a brush pile with the front end loader when the tractor died. There was no loss of power or no sputter, it just died instantly like I had hit a kill switch. Now it won't start. When I put in the key in and turn it, it gives the normal battery and glow plug indicators, but after a few seconds the blinking explanation point indicator comes on. It's displaying an E-20 error which the manual states is Communication Trouble. Their resolution is to contact the Kubota dealer. That happens to be the resolution for every error code, so that doesn't offer much help. Any thoughts? Blown fuse? Bad seat safety switch? I'm not very mechanical so your thoughts are very welcome!
 
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Dave_eng

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M7040, Nuffield 465
Oct 6, 2012
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Williamstown Ontario Canada
I have had bad experiences doing what you did crushing brush piles. Inevitably sticks pop up and may have dislodge an electrical connector.

Get under your machine with a good flashlight and start looking up for broken or dislodged wiring,

Dave
 
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Dave_eng

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M7040, Nuffield 465
Oct 6, 2012
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Williamstown Ontario Canada
Here is some more info but it may not be applicable because you are showing a code.

Lubolt posted a useful diagnostic procedure which works for:
The L01 series models that can be tested using the write-up by Lugbolt are the L3301, L3901, and the L4701.

first is the hourmeter showing any codes (P0606, etc)? If so, call the dealer. There isn't much you can do to them beyond basic stuff...everything else, requires kubota software and hardware.
No codes? Ok do this......
with the key OFF, hold down both of the buttons on the left side of the dash, both at the same time...for a few seconds. Then turn the key on. Look at your hourmeter it should say "A". Let off of those two buttons now. Now, push and hold the RIGHT button, and you'll hear a beep and the hourmeter lcd should show something like 1:(with a number following 1:). Pay no attention to that, when you see 1: let off the right button and don't touch it no more. At this point you can AUDIBLY test every single safety switch's operation. They are all on-off switches. HST pedal switch. Move the pedal forward from neutral and you should hear a beep. Let it return to neutral and once it hits neutral you will hear a beep again. Repeat for reverse, then let it return to neutral, should beep. That lets you know the hst neutral switch is working properly. NO beep? Switch wire is off or switch is bad (two likeliest issues). Repeat for pto switch. engine off for all of the tests. Turn the pto "on" you outta hear a beep. Turn it off and it outta beep again. NO beeps, your pto switch is not sensing an on or off condition check wiring and check the switch to make sure one of them didn't fall off. Repeat again for hi-low range or forward-reverse shifter. Outta beep when it comes out of neutral. Repeat again for seat switch, outta beep when ou get out of the seat. Only other switch would be for parking brake and it is not on the start circuit. Neither is the seat switch. It should at least crank over regardless of whether you're on the seat or not. Once your done playing with the beeper and you have isolated your issue, turn the key off and fix your issue. When you restart, the hourmeter will return to normal.

Dave
 
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Timmer92

Member

Equipment
2019 L3901 (former - BX2370), 72" Brush Hog, 72" Hydraulic Snow Blade, 3pt Auger
Dec 4, 2019
121
15
18
Minnesota
I have had bad experiences doing what you did crushing brush piles. Inevitably sticks pop up and may have dislodge an electrical connector.

Get under your machine with a good flashlight and start looking up for broken or dislodged wiring,

Dave
Thanks Dave. I was thinking the same thing so right after I posted my issue here I went out and checked fuses and looked for wiring issues. I was very lucky and caught sight of the ends of two wires that were just barely sticking out of a cranny. I was able to pull on them, and given the length figure out they had to be connected to something close. I struck my cell camera up with the video on and found the end of a part that looked like it was missing wiring. I pulled out the part and sure enough it looks like the culprit.

I assume this has something to do with the seat? It's got a little plunger on one end that moves in and out and a spring that pushes it to the out position. There is not a single letter or number on it so how do I figure out what to order?

Tractor part 2.jpg


Tractor part.jpg
 

Dave_eng

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M7040, Nuffield 465
Oct 6, 2012
4,640
642
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Williamstown Ontario Canada
This style of switch is more likely related to a clutch pedal, pto selector......... seat switches are not under the tractor.
When I have a bit more time I will try and dig thru the WSM.
Are there any colors and stripes on the two wires?
You need to be under the tractor while someone in the seat sets on pedals and moves levers until you see the one pushing on the plunger.

Please advise which transmission you have as it makes a difference in the switches which will be present.

Another step that can be taken with great caution is to strip the two wires, twist them together and plug them back into their connector. If this is all that is wrong I expect the error code will go away and the tractor will start. If it starts you can experiment with moving various pedals and levers to see if any movement will stop things. I am thinking HST pedal if that is the transmission you have.
Dave
 
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Dave_eng

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M7040, Nuffield 465
Oct 6, 2012
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Looking quickly at Messicks parts I found this safety switch which does not say what it is for but looks the same as your broken one.
forum L3901 switch.jpg

Dave
 
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whitetiger

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Kubota tech..BX2370, RCK60, B7100HST, RTV900 w plow, Ford 1100 FWA
Nov 20, 2011
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That is the neutral safety switch for the hydrostat control pedal.
 
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Timmer92

Member

Equipment
2019 L3901 (former - BX2370), 72" Brush Hog, 72" Hydraulic Snow Blade, 3pt Auger
Dec 4, 2019
121
15
18
Minnesota
Thanks all. I do have a Hydrostatic drive. Admittedly I didn't spend much time under it looking at how it actually works. Given the location it does make sense that it has to do with the pedal.

So do you think that I can twist the wires together as a temporary fix while I'm waiting for the part? I'm not entirely sure I understand what safety this provides and what I'm risking by bypassing it.
 
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Timmer92

Member

Equipment
2019 L3901 (former - BX2370), 72" Brush Hog, 72" Hydraulic Snow Blade, 3pt Auger
Dec 4, 2019
121
15
18
Minnesota
Well, the saga continues. I twisted the ends of the two wires and tried to start it and nothing. I didn't have time to continue looking, maybe I blew a fuse too?
 

whitetiger

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Equipment
Kubota tech..BX2370, RCK60, B7100HST, RTV900 w plow, Ford 1100 FWA
Nov 20, 2011
1,882
561
113
Kansas City, KS
Thanks all. I do have a Hydrostatic drive. Admittedly I didn't spend much time under it looking at how it actually works. Given the location it does make sense that it has to do with the pedal.

So do you think that I can twist the wires together as a temporary fix while I'm waiting for the part? I'm not entirely sure I understand what safety this provides and what I'm risking by bypassing it.
The safety switch keeps the tractor from being started with the hydro pedal out of the neutral position and also kills the engine if the hydro pedal is out of neutral without an operator in the seat.
 

Timmer92

Member

Equipment
2019 L3901 (former - BX2370), 72" Brush Hog, 72" Hydraulic Snow Blade, 3pt Auger
Dec 4, 2019
121
15
18
Minnesota
Update. Aside from crossing the wires that came off the switch, I found an EC fuse was also blown. The tractor is now moving! One item of note is the parking brake indicator is permanently lit. I tried engaging and disengaging the breaks and parking lever, but that did nothing. Do you think when the switch arrives and is installed that indicator will go away?
 

Timmer92

Member

Equipment
2019 L3901 (former - BX2370), 72" Brush Hog, 72" Hydraulic Snow Blade, 3pt Auger
Dec 4, 2019
121
15
18
Minnesota
Update #2. The HST safety switch arrived and I installed it. Not only does it work, but the the parking indicator light issue went away as well. All is good!
 
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