Kubota L5740 "Error - 40" code.

BufordBoone · Feb 8, 2020

RickB said:
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!

BufordBoone · Feb 9, 2020

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.

ptsg · Feb 9, 2020

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.

BufordBoone · Feb 9, 2020

ptsg said:
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.

jaydee325 · Feb 9, 2020

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?

BufordBoone · Feb 9, 2020

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.

LouNY · Feb 9, 2020

BufordBoone said:
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.

jaydee325 · Feb 9, 2020

BufordBoone said:
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.

BufordBoone · Feb 9, 2020

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.