L4701 p0605 code

Jfc

New member

Equipment
Kubota l4701
Aug 27, 2022
3
0
1
Molino fl
Just changed out battery and it’s now showing p0605 code. Will turn over but won’t start?
 

jkrubi12

Well-known member

Equipment
B2601/LA435/QA54"/BH70/B8160box/BB1254/PFL1242/SGC0554/WC-68 Chipper
Sep 24, 2012
400
291
63
right coast
P0605 indicates low battery voltage to the engine control computer; may be rectified by examining & cleaning battery connections, and ensuring that the battery is properly charged and passes a load test.

My research indicates the engine control computer did not 'complete' a pre-start internal check; If your battery is not suspect, disconnect for 15 minutes (a rough guess on the time, an hour wouldn't hurt), ensure clean connections and re-connect battery, then try restart. Hopefully a solid battery connection would allow the engine control computer to pre-test 'completely' and allow a start.
 

Jfc

New member

Equipment
Kubota l4701
Aug 27, 2022
3
0
1
Molino fl
Thank you. Keep you posted
P0605 indicates low battery voltage to the engine control computer; may be rectified by examining & cleaning battery connections, and ensuring that the battery is properly charged and passes a load test.

My research indicates the engine control computer did not 'complete' a pre-start internal check; If your battery is not suspect, disconnect for 15 minutes (a rough guess on the time, an hour wouldn't hurt), ensure clean connections and re-connect battery, then try restart. Hopefully a solid battery connection would allow the engine control computer to pre-test 'completely' and allow a start.
[/QUOTE
 

Jfc

New member

Equipment
Kubota l4701
Aug 27, 2022
3
0
1
Molino fl
Thank you. Keep you posted
It’s a brand new battery. Took connections off cleaned them up. Left off for a little over an hour. Turned key and code still came up and still no start? Not sure how to clear code? needs priming maybe? Just seems like it’s not getting gas?
 

jkrubi12

Well-known member

Equipment
B2601/LA435/QA54"/BH70/B8160box/BB1254/PFL1242/SGC0554/WC-68 Chipper
Sep 24, 2012
400
291
63
right coast
Check to see if headlights appear normally lit. If battery & related connections appear normal, it's likely that the engine control computer has been compromised in some way due to low voltage.

I found some threads with additional information:



Based on reading these you may have (unfortunately) a much more serious issue than you originally thought; a 'bad' ECU (engine control module). :eek:
 

pablack

New member

Equipment
MX5200
Aug 29, 2022
4
0
1
NC
I just had the same issue occur. Tractor started normal and while mowing I hopped off the tractor while the rotary cutter was still engaged, which shut the tractor off. When I attempted to restart the tractor nothing happened except that the gauge lights dimmed. There was also an E94 code that I believe is related to the seat switch that showed up on the display. I was able to jump start the tractor, so i turned off the tractor, removed the battery. I had the auto parts store check the battery and they confirmed that it was bad. I purchased a new battery and when I replaced it, the tractor turned over normally but would not start. The P0605 error was displayed along with the E94 code.

It sounds like there is an issue with Kubota's and changing the batteries.

I'm really hoping this does not turn out to be an ecm replacement.............
 
Last edited:

jkrubi12

Well-known member

Equipment
B2601/LA435/QA54"/BH70/B8160box/BB1254/PFL1242/SGC0554/WC-68 Chipper
Sep 24, 2012
400
291
63
right coast
I'm really hoping this does turn out to be an ecm replacement.............
'DOES' or 'DOES NOT'....ECM replacement?? Those things are $$$! :oops:

I'm really hoping that this ECM problem is isolated to tractors above 26HP (i.e, those with emissions control equipment).

I don't think that my B2601 has an EGR system. Good luck to both of you(y)
 

pablack

New member

Equipment
MX5200
Aug 29, 2022
4
0
1
NC
Update on the status of the MX5200. @Jfc - Not trying to hijack your thread, just thought I would share my experience since it seems to be a similar issue.

I took the trailer over to the orchard to pickup the tractor to take to the dealer. I tried to start the tractor but it just turned over and would not fire (same as before). Error codes e94 and P0605 were still on the display.

I was using my mini ex to pull the tractor up to the trailer since the tractor was on a slight incline. I got the tractor to the trailer and was going to use the starter to help lift the bucket. The tractor fired up and ran with the error codes still showing. I turned the tractor off and restarted just to check. I decided to finish mowing.

After i finished mowing, I loaded the tractor up on the trailer to return to the other property where i keep the tractor. When i arrived at the other property I tried to start the tractor. It would just turn over, same as before.

This is a little encouraging as it would seem to indicate that it is a wiring issue and not necessarily the ecm.

Can anyone confirm if the errors can be reset with an OBD II scanner? Or is a trip to the dealer required to reset the errors. If the dealer has to reset the codes then I will likely just take the tractor to the dealer and let them troubleshoot the issue (and fix the fuel gauge!). If i can reset then I will likely inspect the wiring first.
 

jkrubi12

Well-known member

Equipment
B2601/LA435/QA54"/BH70/B8160box/BB1254/PFL1242/SGC0554/WC-68 Chipper
Sep 24, 2012
400
291
63
right coast
@pablack, have you researched the e94 code? A quick search indicates it may be due to some type of faulty wiring. That would seem like good news to me, even if it was related to a safety switch - it could mean that the switch went 'safety' on you. THAT should reset by itself I would imagine, unless it is a damaged wire within the harness.

The other code (p0605) is definitely ECU/ECM related and, since your tractor started, may be able to be erased using a OBDII scanner. I would try to erase it forthwith with a scanner, then conduct a starting test to see if it comes back. If it does come back, and your battery voltage is not in question, you may need a dealer's computer to connect & remove it.

Even if a dealer was able to remove the code and get your tractor running normally I would bet that the code would remain in the ECU as proof of a past issue (possibly referred to as a permanent stored code, just not presently active).

Good luck! (y)
 

pablack

New member

Equipment
MX5200
Aug 29, 2022
4
0
1
NC
Just got confirmation from the Kubota dealer that there is an internal ecu error that requires the ecu/ecm to need to be replaced. Quote is $3000 for ecu and labor. Dealer said they don't know the cause but tried to blame the 3rd function that has been installed since the tractor was new (2016) or storing the tractor outside in the rain (tractor has been stored in our barn since we purchased in 2016).

Extremely disappointed that Kubota does not seem to have any circuit protection for the ecu/ecm. I've changed a lot of batteries in my life in both vehicles and equipment and never had an issue like this occur......
 

jkrubi12

Well-known member

Equipment
B2601/LA435/QA54"/BH70/B8160box/BB1254/PFL1242/SGC0554/WC-68 Chipper
Sep 24, 2012
400
291
63
right coast
FWIW, I have a computerized battery 'conditioner' (NOCO Genius 7200) that has a 'power supply mode', apparently intended to be used while replacing diesel batteries.

I found out the hard way while replacing the batteries in my Cummins diesel pickup what this 'mode' is intended for; took me over 700 miles for the ECM to 're-learn' and re-set 7 error code indicators after battery replacement (2 batteries). :eek:
 
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fried1765

Well-known member

Equipment
Kubota L48 TLB, Ford 1920 FEL, Ford 8N, SCAG Liberty Z, Gravely Pro.
Nov 14, 2019
7,847
5,072
113
Eastham, Ma
FWIW, I have a computerized battery 'conditioner' (NOCO Genius 7200) that has a 'power supply mode', apparently intended to be used while replacing diesel batteries.

I found out the hard way while replacing the batteries in my Cummins diesel pickup what this 'mode' is intended for; took me over 700 miles for the ECM to 're-learn' and re-set 7 error code indicators after battery replacement (2 batteries). :eek:
My Mercedes E-350 is electrically quite similar.
12V power must be maintained on the system when replacing a battery.
I just use jumper cables from another 12V source.
If 12V power is not maintained = $ reset trip to the dealer!
 
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jkrubi12

Well-known member

Equipment
B2601/LA435/QA54"/BH70/B8160box/BB1254/PFL1242/SGC0554/WC-68 Chipper
Sep 24, 2012
400
291
63
right coast
I didn't find out that a problem had been created (truck seemed to be running normally) until I took it in for the annual state inspection and it was rejected with four 'sensors' listed as 'not ready'.

Did a ton of research and figured out that it just needed miles to allow the ECM to reset. I did those miles with my scan tool attached to the OBDII port and gradually all the sensors went 'green' and I got a free re-test and passed.

Over forty years of driving and that was the first time one of my vehicles did not pass the inspection process! :mad:
 

retyred57

New member

Equipment
L3901 HST, Ag tires, LA525 FEL, Landpride 66" boxblade, BE 60" rotary cutter
Aug 3, 2015
15
6
3
Ontario, Canada
I just had the same issue occur. Tractor started normal and while mowing I hopped off the tractor while the rotary cutter was still engaged, which shut the tractor off. When I attempted to restart the tractor nothing happened except that the gauge lights dimmed. There was also an E94 code that I believe is related to the seat switch that showed up on the display. I was able to jump start the tractor, so i turned off the tractor, removed the battery. I had the auto parts store check the battery and they confirmed that it was bad. I purchased a new battery and when I replaced it, the tractor turned over normally but would not start. The P0605 error was displayed along with the E94 code.

It sounds like there is an issue with Kubota's and changing the batteries.

I'm really hoping this does not turn out to be an ecm replacement.............
I remove the battery in my L3901 for the winter months and use a battery maintainer to keep it charged. I have never had a problem with starting when I install battery again in the spring.
 

pablack

New member

Equipment
MX5200
Aug 29, 2022
4
0
1
NC
I remove the battery in my L3901 for the winter months and use a battery maintainer to keep it charged. I have never had a problem with starting when I install battery again in the spring.
Retyred

What year model is your L3901? What procedure do you use to remove the battery (remove positive or negative first? other steps?)

Also, the battery that failed in the tractor failed during use. The tractor started normally before use and then would not start after i had been using for an hour or so. It seems like the battery may have shorted out internally (??). This could have contributed to the issue.

Key points are:
1) This is not an isolated problem - i've read several threads on various forums that have stated similar issues related to battery changes..
2) The ECM circuit protection is not very robust. Dealer stated that the ECM experienced an internal fault that cannot be reset.
3) Be careful jumping or changing a battery in a Kubota.

Other tidbits that may or may not have some contribution to the issue are:
1) The fuel gauge has not worked for a couple of years. Maybe there was some damage to the wiring caused by mice?
2) The dealer did find a couple of connector pins that had arced (not sure what connector).
 

retyred57

New member

Equipment
L3901 HST, Ag tires, LA525 FEL, Landpride 66" boxblade, BE 60" rotary cutter
Aug 3, 2015
15
6
3
Ontario, Canada
Retyred

What year model is your L3901? What procedure do you use to remove the battery (remove positive or negative first? other steps?)

Also, the battery that failed in the tractor failed during use. The tractor started normally before use and then would not start after i had been using for an hour or so. It seems like the battery may have shorted out internally (??). This could have contributed to the issue.

Key points are:
1) This is not an isolated problem - i've read several threads on various forums that have stated similar issues related to battery changes..
2) The ECM circuit protection is not very robust. Dealer stated that the ECM experienced an internal fault that cannot be reset.
3) Be careful jumping or changing a battery in a Kubota.

Other tidbits that may or may not have some contribution to the issue are:
1) The fuel gauge has not worked for a couple of years. Maybe there was some damage to the wiring caused by mice?
2) The dealer did find a couple of connector pins that had arced (not sure what connector).
I bought the tractor in 2015, always remove negative cable first when removing battery and install positive cable first when installing battery.
 

whitetiger

Moderator
Staff member

Equipment
Kubota tech..BX2370, RCK60, B7100HST, RTV900 w plow, Ford 1100 FWA
Nov 20, 2011
2,949
1,401
113
Kansas City, KS
About clearing codes, I found this in my L3901 WSM:
That will only clear the DTCs from the dash panel, someone or your dealer has to use Diagmaster to permanently erase them from the ECU.