Regeneration issues

rsanford

New member
Oct 6, 2019
8
5
3
Millington, TN
Hello all. I have a L3901 about 4 years old with about 250 hours on it. Before, I would be out mowing and the regen light would come on and I would just keep doing my thing and it would do its things and turn off. This morning my sister next door borrowed it to use the front bucket for about 30 minutes or so. When I cranked it to put it up apparently the regen had started and been interrupted. It is beeping every 3 seconds and the regen indicator, the rpm increase and the parked regen lights are all flashing. The manual says to continue to work to raise DPF temp and increase rpm until the rpm indicator turns off. The tractor was already warm so I increased the rpm up to the 540 or a little above and there was no change.

I then tried the parked regen procedure and when I crank the tractor all three of the lights are flashing and it is beeping every 3 seconds. I did everything up to no. 7 - Press the dpf inhibit switch and the switch turns off. Up to that point, the switch was unlit and when I push it, it lights up and revs up a little. No. 8 says the parked regen switch lamp will start flashing. It never does and pushing doesn’t seem to do anything. No 9 is to press the parked regen switch and it will stop flashing and stay lit and the process will start. Like I said I never get past 8.

Can anybody tell me what I am doing wrong on the parked regen procedure. Could my parked regen switch be bad.

Or should I wait a few days for things to dry up and take it out to mow and try the first procedure with the thought that maybe I did not let it get hot enough or rev up enough. Any help much appreciated. Thanks. Raleigh.
 

fried1765

Well-known member

Equipment
Kubota L48 TLB, Ford 1920 FEL, Ford 8N, SCAG Liberty Z, Gravely Pro.
Nov 14, 2019
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Eastham, Ma
Hello all. I have a L3901 about 4 years old with about 250 hours on it. Before, I would be out mowing and the regen light would come on and I would just keep doing my thing and it would do its things and turn off. This morning my sister next door borrowed it to use the front bucket for about 30 minutes or so. When I cranked it to put it up apparently the regen had started and been interrupted. It is beeping every 3 seconds and the regen indicator, the rpm increase and the parked regen lights are all flashing. The manual says to continue to work to raise DPF temp and increase rpm until the rpm indicator turns off. The tractor was already warm so I increased the rpm up to the 540 or a little above and there was no change.

I then tried the parked regen procedure and when I crank the tractor all three of the lights are flashing and it is beeping every 3 seconds. I did everything up to no. 7 - Press the dpf inhibit switch and the switch turns off. Up to that point, the switch was unlit and when I push it, it lights up and revs up a little. No. 8 says the parked regen switch lamp will start flashing. It never does and pushing doesn’t seem to do anything. No 9 is to press the parked regen switch and it will stop flashing and stay lit and the process will start. Like I said I never get past 8.

Can anybody tell me what I am doing wrong on the parked regen procedure. Could my parked regen switch be bad.

Or should I wait a few days for things to dry up and take it out to mow and try the first procedure with the thought that maybe I did not let it get hot enough or rev up enough. Any help much appreciated. Thanks. Raleigh.
Stories like this make me love my 2006 Kubota L48 TLB even more!
 
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NCL4701

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L4701, T2290, WC68, grapple, BB1572 box scrape, Howes 500, 16kW IMD gen, WG24
Apr 27, 2020
2,489
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Central Piedmont, NC
I have interrupted a normal regen a total of once on mine. Hydraulic line blew about 2 minutes into regen and it was before any valve so no way to stop it other than shut it down. So it was either leave it running and pump all the hydraulic/trans fluid into the ground burning up who knows what all or shut it down. I shut it down, replaced the hose, restarted (after a brief but fervent prayer) about an hour and a half after shutdown. The increase RPM light came on (nothing else), increased RPM until it went solid, and it completed the regen normally. That was about 200 hours and a few regens ago. Normal operation since.

I’m aware that didn’t fully address your question. Just an experience with interrupted regen.
 

rsanford

New member
Oct 6, 2019
8
5
3
Millington, TN
I have interrupted a normal regen a total of once on mine. Hydraulic line blew about 2 minutes into regen and it was before any valve so no way to stop it other than shut it down. So it was either leave it running and pump all the hydraulic/trans fluid into the ground burning up who knows what all or shut it down. I shut it down, replaced the hose, restarted (after a brief but fervent prayer) about an hour and a half after shutdown. The increase RPM light came on (nothing else), increased RPM until it went solid, and it completed the regen normally. That was about 200 hours and a few regens ago. Normal operation since.

I’m aware that didn’t fully address your question. Just an experience with interrupted regen.
Thanks. I am hopeful that shutting mine down for a few days with a full cool down might result in the same thing.
 

SDT

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multiple and various
Apr 15, 2018
3,084
923
113
SE, IN
“My ____ borrowed the tractor and when it came back it’s __\_________” such a common story
Bingo.

Though I sometimes do work favors for others, I NEVER loan anything.

Cannot help much with your regen issue but suggest that you read, reread, and read again the regen materials in your Operator's Manual before doing anything more especially if your tractor is still within the 5 year emissions warranty.

Kubota dealers and factory service reps are trained to look for anything that can be construed as "operator error" in order to deny such warranty claims.

Fortunately, models such as yours are usually seamless but it is likely that you will now need to perform a so-called parked regen.

Good luck.

SDT
 
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B737

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LX3310
Jun 9, 2019
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New Jersey
Im not sure if the regen logic on the L is the same as the LX, I suspect it is, but you should not be pressing the inhibit switch. That switch needs to not be lit (not activated). Parking brake set, PTO off, HST pedal neutral, engine idle, push parked regen button when it is flashing and these parameters have been met. EGT and coolant targets need to be met so it may take a bit for the regen light to become solid but the ECU will control engine RPM during the procedure. After its completed wait at least 5 minutes before shutting down.

An illuminated inhibit button (at least on the LX) means inhibit mode is active, you dont want that.
 
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jimh406

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Kubota L2501 with R4 tires
Jan 29, 2021
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I hope you get it sorted out. It would be easy if an enduser could force a regen. Btw, it’s not just tractors. Trucks have the same achilles heal. Really a shame when the fix would be so simple.
 
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NCL4701

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L4701, T2290, WC68, grapple, BB1572 box scrape, Howes 500, 16kW IMD gen, WG24
Apr 27, 2020
2,489
3,508
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Central Piedmont, NC
“My ____ borrowed the tractor and when it came back it’s __\_________” such a common story
I thought about saying that but thought it might be salt in a wound. However, I do agree. Even those familiar with tractors aren’t always familiar with the specifics of regen, HST, and other more modern or unique characteristics. Everyone who borrows my tractor gets a bonus (or cost depending on their perception); ME.
 

sheepfarmer

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L3560, B2650, Gator, Ingersoll mower
Nov 14, 2014
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MidMichigan
Hello all. I have a L3901 about 4 years old with about 250 hours on it. Before, I would be out mowing and the regen light would come on and I would just keep doing my thing and it would do its things and turn off. This morning my sister next door borrowed it to use the front bucket for about 30 minutes or so. When I cranked it to put it up apparently the regen had started and been interrupted. It is beeping every 3 seconds and the regen indicator, the rpm increase and the parked regen lights are all flashing. The manual says to continue to work to raise DPF temp and increase rpm until the rpm indicator turns off. The tractor was already warm so I increased the rpm up to the 540 or a little above and there was no change.

I then tried the parked regen procedure and when I crank the tractor all three of the lights are flashing and it is beeping every 3 seconds. I did everything up to no. 7 - Press the dpf inhibit switch and the switch turns off. Up to that point, the switch was unlit and when I push it, it lights up and revs up a little. No. 8 says the parked regen switch lamp will start flashing. It never does and pushing doesn’t seem to do anything. No 9 is to press the parked regen switch and it will stop flashing and stay lit and the process will start. Like I said I never get past 8.

Can anybody tell me what I am doing wrong on the parked regen procedure. Could my parked regen switch be bad.

Or should I wait a few days for things to dry up and take it out to mow and try the first procedure with the thought that maybe I did not let it get hot enough or rev up enough. Any help much appreciated. Thanks. Raleigh.
I think the problem is pushing the dpf regen inhibit button in step 7. The light should be off in the more recent models.

First to clarify, what does the button look like on yours? Does it have a diagonal slash on it? The first year these tractors were made, the automatic condition when started was regen inhibited, the button looked different and you had to push that button to allow auto regen.

Any idea if your sister pushed that button to inhibit the regen or did she just shut the tractor off?

In any case my guess is you should push the button again to make sure the light is off, and then see if it won't proceed with an auto regen or the parked regen.
 
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Bark

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L4701/FM2560LA765/BB2560Pittsburgh disk Titan P forks
Feb 18, 2020
202
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28
North CA
I hope you get it sorted out. It would be easy if an enduser could force a regen. Btw, it’s not just tractors. Trucks have the same achilles heal. Really a shame when the fix would be so simple.
I have been wanting to do a regen when I am spending hours disking (a perfect time for a regen) so I had written Kubota about it. I am trying to find the email response I got back from Kubota telling me why they didn't put that option on my L4701. The response they sent back made no sense at all.
Still love my Kubota but as you said, the fix seems to be so simple.
 
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rsanford

New member
Oct 6, 2019
8
5
3
Millington, TN
Thanks for all the replies. I will crank it again in a couple of days and see if it will proceed to auto and if so do some mowing. If not, try parked regen again paying attention to the step 7 issue. The auto on mine was regen not inhibited and when I push the button with the slash it lights up and is inhibited I guess. So my understanding is I don’t want that on for auto or parked regen.
 

B737

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LX3310
Jun 9, 2019
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correct, do not push the inhibit button, it should not be illuminated solid.
I believe after it starts asking for parked regen, I dont think doing a regen while tractoring is an option anymore.
 

kubotafreak

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GRAND l6060, L3560, B6100, gr2100, tg 1860, g1800, g1900, g2160
Sep 20, 2018
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Arkansas, US
I think that button changed depending on model and series. I had one that said dpf (auto), which is exactly how it sounds. When lit it would commence regen when it was required. By not pressing the auto button you were essentially telling the machine to not regen without permission...

My new tractor says dpf (inhibit). This is essentially the opposite of the prior model. Where as it is in auto mode by default and you actively press the button to inhibit the dpf regen. This would be for those times in a confined space(barn) or some other non dpf friendly time.
 
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B737

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LX3310
Jun 9, 2019
2,024
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New Jersey
I think that button changed depending on model and series. I had one that said dpf (auto), which is exactly how it sounds. When lit it would commence regen when it was required. By not pressing the auto button you were essentially telling the machine to not regen without permission...

My new tractor says dpf (inhibit). This is essentially the opposite of the prior model. Where as it is in auto mode by default and you actively press the button to inhibit the dpf regen. This would be for those times in a confined space(barn) or some other non dpf friendly time.
wow so with the older system, you had to turn ON auto regen, so it was in inhibit by default? where as today auto is on by default...
when did they change this?
 
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SDT

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multiple and various
Apr 15, 2018
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wow so with the older system, you had to turn ON auto regen, so it was in inhibit by default? where as today auto on by default...
when did they change this?
Bingo.

Current models have "Inhibit" button, which is prudent in the excessively litigant US market so as to protect Kubota from fire claims when operating within barns, etc., when exhaust temperatures are higher than normal.

Don't like it?

Thank the federales.

SDT
 
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B737

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LX3310
Jun 9, 2019
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geez what a cluster to reverse the logic like that, not very intuitive.
 

rsanford

New member
Oct 6, 2019
8
5
3
Millington, TN
Thanks. I searched and found a video on Youtube about a bad parking brake safety switch. I checked and my parking light was not coming on on so I looked underneath and my problem was not a bad safety switch. The two prongs going in the connector had pulled out. I disassembled it and clicked them back in place and reinserted and problem solved. Not exactly the same thing but without this video I never would have started checking there. The parked regen completed without problem.

So with my tractor, I have added in the manual under step 2 to apply parking brake "and make sure dash light is on." I also marked out step 7.
 
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B737

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LX3310
Jun 9, 2019
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New Jersey
Wow nice find
with the connection not working you probably weren’t far from a plugged DFP and a trip to the dealer, that was a really good catch!