Kubota L5740 "Error - 40" code.

   / Kubota L5740 "Error - 40" code. #1  

BufordBoone

Platinum Member
Joined
May 31, 2014
Messages
515
Location
Tuscaloosa, Al
Tractor
Kubota L5740 & M7060
My 2013 L5740 won't start. It is a cabbed model.

I turn the key and get "Error-40". It won't even turn over.

I looked this up in the shop manual and see it says: Input voltage to sensor from ECU is failed. Probable cause is Sensor input voltage drop below 2.6 V for 0.1 second or more Ground wire of lever sensor short-circuited

Remedy is shown as: Check the ground cable Check the input voltage at ECU connector Check the sensor connector

I found the main ground cable but I can't find the ECU ground cable. There is a photo in the manual but it is so close up that I can't tell where the ECU is located.

I've gone thru every fuse I can find. I've taken the dashboard off. I've checked the battery (original) and it has more than 12 Volts both on the terminals and on the connectors (showing the connectors are not loose).

Does anyone know where the ECU is located?

Anyone else ever had the "Error-40" code? What did you do to fix it?

Thanks, in advance, for any help you may be able to provide.
 
   / Kubota L5740 "Error - 40" code. #2  
Just because the cables have 12 volts under close to zero load doesn’t mean all the connections are good. Try checking the voltage at the starter while you attempt to start it and see if it maintains 12 volts.
 
   / Kubota L5740 "Error - 40" code.
  • Thread Starter
#3  
I'll give that a try, 4570 man but the starter doesn't even turn over if I try to turn the key.
 
   / Kubota L5740 "Error - 40" code. #4  
Does the starter attempt to engage or make any noise at all? I’m betting either your 7 year old battery is done for or there’s a bad connection somewhere.
 
   / Kubota L5740 "Error - 40" code. #5  
Here is a picture from the WSM. Doesn't help much but it looks like it's under the parking brake I believe.

kubotaECU.jpg
 
   / Kubota L5740 "Error - 40" code.
  • Thread Starter
#6  
Here is a picture from the WSM. Doesn't help much but it looks like it's under the parking brake I believe.

View attachment 640752

Thanks, ptsg. That is one photo I have that I can't figure out where it is. By "parking brake" do you mean the lever I pull to lock the brakes?

The other picture (which I can't seem to figure out how to attach) is above that one you posted on page 9-S39
 
   / Kubota L5740 "Error - 40" code.
  • Thread Starter
#7  
Edit - Typed this in reply to a recommendation about winching the tractor onto a trailer. Don't see that reply any more.

It is going to have to be winched from the front as it has a mower attached to the back. I can disconnect the mower but have no way to move it once disconnected. I had thought of using my M7060 to lift the L5740 loader.

Guess I could detach the mower from the little tractor and use the M7060 to move it then could winch the tractor backward.

Thanks to all for the quick responses.
 
Last edited:
   / Kubota L5740 "Error - 40" code.
  • Thread Starter
#8  
Does the starter attempt to engage or make any noise at all? I’m betting either your 7 year old battery is done for or there’s a bad connection somewhere.

Nope, no attempting to engage or making any noise. Perhaps I'll hook up some jumper cables and try to jump start it.
 
   / Kubota L5740 "Error - 40" code. #9  
Nope, no attempting to engage or making any noise. Perhaps I'll hook up some jumper cables and try to jump start it.

That’s what I would do before putting much effort into it.
 
   / Kubota L5740 "Error - 40" code. #10  
Edit - Typed this in reply to a recommendation about winching the tractor onto a trailer. Don't see that reply any more.

It is going to have to be winched from the front as it has a mower attached to the back. I can disconnect the mower but have no way to move it once disconnected. I had thought of using my M7060 to lift the L5740 loader.

Guess I could detach the mower from the little tractor and use the M7060 to move it then could winch the tractor backward.

Thanks to all for the quick responses.

Sorry, somehow I replied to the wrong thread. Realizing that I deleted my comment. I have since replied in the proper place. Sorry for any confusion.
 
   / Kubota L5740 "Error - 40" code.
  • Thread Starter
#11  
Sorry, somehow I replied to the wrong thread. Realizing that I deleted my comment. I have since replied in the proper place. Sorry for any confusion.

No worries, RickB. Thanks for trying to help!
 
   / Kubota L5740 "Error - 40" code.
  • Thread Starter
#12  
View attachment ECU location.pdf

Figured out how to get a photo of the page on here. Can anyone advise the location of either of the photos on a Cabbed 2013 L5740?

They are too close-up for me to figure out.

Thanks.

Edited to add: Sorry, I thought that would appear in the body instead of requiring you to click it.
 
   / Kubota L5740 "Error - 40" code. #13  
To me it looks like it's on the left side of the seat. Right behind the lever for the 4WD (?).

On another picture there was a parking brake lever above the ECU, that's why I mentioned it before. Might not apply to your tractor.
 
   / Kubota L5740 "Error - 40" code.
  • Thread Starter
#14  
To me it looks like it's on the left side of the seat. Right behind the lever for the 4WD (?).

On another picture there was a parking brake lever above the ECU, that's why I mentioned it before. Might not apply to your tractor.

I'll take a look there, ptsg. All input is certainly appreciated.
 
   / Kubota L5740 "Error - 40" code. #15  
I looked at the Kubota parts list for the L5740 and found nothing with the description of ECU (I certainly could have missed it). Lots of sensors though. It appears that this tractor has mechanical fuel injection with no exhaust after treatment, so it would not surprise me that it does not have an ECU.

I'm wondering if the Dash Panel Assembly (Pt# TD179-30202) is where the sensors report to and the error codes are generated?
 
   / Kubota L5740 "Error - 40" code.
  • Thread Starter
#16  
I plan to try hooking up jumper cables to see if that might work. If it doesn't, I'll disconnect the battery for 5-10 minutes to see if it resets something.

I'm running out of ideas.

Thanks to all.
 
   / Kubota L5740 "Error - 40" code. #17  
My 2013 L5740 won't start. It is a cabbed model.

I turn the key and get "Error-40". It won't even turn over.

I looked this up in the shop manual and see it says: Input voltage to sensor from ECU is failed. Probable cause is Sensor input voltage drop below 2.6 V for 0.1 second or more Ground wire of lever sensor short-circuited

Remedy is shown as: Check the ground cable Check the input voltage at ECU connector Check the sensor connector

I found the main ground cable but I can't find the ECU ground cable. There is a photo in the manual but it is so close up that I can't tell where the ECU is located.

I've gone thru every fuse I can find. I've taken the dashboard off. I've checked the battery (original) and it has more than 12 Volts both on the terminals and on the connectors (showing the connectors are not loose).

Does anyone know where the ECU is located?

Anyone else ever had the "Error-40" code? What did you do to fix it?

Thanks, in advance, for any help you may be able to provide.


As I read your post I have to ask what is the lever sensor?
And it references the voltage signal to the ECU from that sensor.
Is that a sensor that pulls signal voltage to a ground? That is how it reads to me.
If that is the case disconnect the sensor and see if the error goes away.
Many of the newer systems have a 5 volt supply from the ECU to the various sensors to ground and monitors the voltage pull down as a signal.
 
   / Kubota L5740 "Error - 40" code. #18  
I plan to try hooking up jumper cables to see if that might work. If it doesn't, I'll disconnect the battery for 5-10 minutes to see if it resets something.

I'm running out of ideas.

Thanks to all.

Have you verified that you have a known good fully charged battery by a load test? The battery needs to read greater than or equal to 12.6 volts (rested) to be fully charged and verified good by a load test. This is where electrical trouble shooting should always start. Otherwise, you are chasing your tail!

A bad battery will cause all kinds of weird voltage readings in a circuit.
 
   / Kubota L5740 "Error - 40" code.
  • Thread Starter
#19  
Well, we found the ECU. It is on the left, under the seat. Yep, had to take the seat out. Thanks for the recommendation, ptsg. Unfortunately we couldn't find anything wrong with it. Error code persists.

Prior to removing the seat, I disconnected the battery for about 5 minutes, turned key to discharge any residual power then connected it back up. Hooked up jumper cables to my truck and...nothing changed. Still the same "Error-40".

I plan to do a bit more research but fear this one may require a trip to the shop.

Thanks, to all, for the assistance.
 

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