MX5800 P0605 Code Help! **UPDATE**

[SkylineAcres16]

Saturday I was grading my driveway with my 2016 MX5800 and was running the tractor for about 2 hours with absolutely no problems. The tractor had been sitting in the pole barn for a month but it started right up, no problems. As I was grading the driveway, I turned the tractor off to grab a drink and a shovel. 10 minutes later I go to re-start the tractor and when I did all of the dash lights were blinking really fast and the gauges were fluttering and the engine would turn over very slow. Since the tractor is a 2016 model I figured the battery had went bad so I checked it and it was only showing 12.2 V after running for 2 hours. Also, I keep it hooked it hooked up to a battery tender in the barn so it should have been more like 12.65 V. I went to Advance and had them check the battery and it tested bad so I bought a new one and put in the tractor.

Now, here is the problem. The tractor turns over and cranks just like normal, there is the clicking of the fuel solenoid or whatever it is, glow plug light comes on and goes off, and the gauges don't flutter or anything but the tractor does not start. It is showing a P0605 code which from Googling and talking to the dealer is a ECU communication problem. I have tried everything from leaving the battery unhooked for a long time and using the code clear procedure that I found online where you hold down the 2 DPF buttons and go through the process and it still won't clear the code. So now my brain is naturally thinking worst case scenario and the bad battery fried the ECU and now I'm going to have to spend several thousand dollars!

Does anyone have any more advice that they can offer me? I have checked all fuses with a multimeter and done a visual inspection of the wires and everything looks good. I called the dealers around me and all of them are between 1-4 weeks out with service and they also say no diagnostic work can be done on-site and the tractor needs to come in. Let's look at best case scenario, does anyone know if there are codes that only the dealer can clear with their software and without clearing the tractor won't start? That would at least be better than buying a new ECU. Also, on that note does KTAC cover this? Their website says mechanical breakdowns are not included so I am guessing not? This tractor has been flawless for the 6 years I have owned it since new but now I am pretty frustrated; especially if I need to spend big bucks to fix it. Thanks in advance.

 

[North Idaho Wolfman]

Yes the dealer needs to clear that code in order for it to run.
It could be as simple as that.
If they can not clear the code or the ECM is damaged then yes it will need to be replaced and programed so a dealer will need to do it.
KTAC has been know to replace ECM's when they get damaged in the past, but I have heard they are updating what they will actually cover.

 

[SkylineAcres16]

Thank you for your reply. I am hoping that it is a code that only dealers can clear and the tractor is back to running. That would be a whole lot cheaper than a new ECU. So is it correct to say that there are codes that regular individuals can clear through the dash and then there are codes that only dealers can clear? I am still surprised that out of 3 dealers none of them acted like they do service calls. They all more or less said the tractor has to come in to the shop. One of them even told me they tried taking the laptop out in the field and for whatever reason it didn't work so well and they no longer do it.

 

[North Idaho Wolfman]

Thank you for your reply. I am hoping that it is a code that only dealers can clear and the tractor is back to running. That would be a whole lot cheaper than a new ECU. So is it correct to say that there are codes that regular individuals can clear through the dash and then there are codes that only dealers can clear? I am still surprised that out of 3 dealers none of them acted like they do service calls. They all more or less said the tractor has to come in to the shop. One of them even told me they tried taking the laptop out in the field and for whatever reason it didn't work so well and they no longer do it.

Yes there are codes that only the dealers can reset.

 

[GreensvilleJay]

well that's a royal PITA.....
change the battery ( a 'normal' thing) and dealer HAS to reset the computer ??
talk about a 'make money SCAM'...

 

[SkylineAcres16]

Yeah it is a big PITA. Especially when the 3 dealers within 1 hour of me cannot look at the tractor between 1-4 weeks from now but yet they have to be the ones to reset it (considering that's the problem). Could you imagine being in the middle of making hay (we make our own small square bales) or doing work at a friends house or buying thousands of dollars of fertilizer to put down (was going to do this this weekend with MX) and your battery going out and you literally cannot start the tractor to finish your hay or bring it back home from your friends house or etc until a dealer resets a code; 1-4 weeks later? Now I don't want to spread false information that this happens everytime your battery goes out or anything because people's batteries go out everyday and don't have this problem but what I can tell you is that it happened to me. I actually used to work for Interstate Batteries for 10 years and I have seen batteries go out in weird ways and this was one of them.

 

[GreensvilleJay]

I'd be furious,and that's putting it very, very mildly. There is NO way this should happen 'dealer needs to reset code' BS. I'd be calling Kubota Canada for immediate service. If they said 'no', I'd just say, fine, stay up and watch the 'news at 11' tonight. I'm a Gemini..my good half gets mad, the 'other' gets even,you don't want to see the 'other' in action

 

[whitetiger]

Yeah it is a big PITA. Especially when the 3 dealers within 1 hour of me cannot look at the tractor between 1-4 weeks from now but yet they have to be the ones to reset it (considering that's the problem). Could you imagine being in the middle of making hay (we make our own small square bales) or doing work at a friends house or buying thousands of dollars of fertilizer to put down (was going to do this this weekend with MX) and your battery going out and you literally cannot start the tractor to finish your hay or bring it back home from your friends house or etc until a dealer resets a code; 1-4 weeks later? Now I don't want to spread false information that this happens everytime your battery goes out or anything because people's batteries go out everyday and don't have this problem but what I can tell you is that it happened to me. I actually used to work for Interstate Batteries for 10 years and I have seen batteries go out in weird ways and this was one of them.

If you are unable to clear the code in Mode b, the failure is still active. You can not clear an active code until the problem is rectified.

Disconnecting the battery does not require a reset on these tractors and leaving it disconnected will not clear anything. Your battery failure may indeed have damaged the ECU.

Attached is a list of the PO error codes for the L & MX series tractors.

 

[lugbolt]

if there is any code displayed in the panel, it is simply displayed there. There is a way to remove it from the panel, but it does not remove it from the ecu. That can only be done at the dealer.

Some of those displayed codes will repopulate immediately after "clearing" from the panel, and P0605 is one of those, as I remember.

Don't like it? Tough. It's the way it's going to be from about 2013 on. You can contact your congressional members and express your displeasure with them. Manufacturers are making it as easy as possible yet still meet all applicable laws and regulations. Key part of that is "as easy AS POSSIBLE". Remember none of this stuff is new, automotive industry has been using it for decades, it is all very very similar.

 

[GreensvilleJay]

I grabbed that WSM...saw 'CAN' listed, sighed.....
You 'might' get lucky by disconnecting battery, then unplug/install the various CAN connectors several times, then reconnect battery.
CAN is a miserable communications 'system'. Something as SIMPLE as a wonky pin on one plug can cause it to 'fail'. A 'cold boot' sometimes restores things as they should be.
Will this work for you ? 50/50 chance...at least you'll eliminate a probable culprit.

 

[lugbolt]

yes can communication error.

Sometimes it's a wiring issue, other times it's an ecu issue. More often ECU on kubota, in my limited experience.

can stands for controller area network. Basically it can be thought of as a party line. Multiple components talking on the same line more or less. It's not that complicated but it can be if you let it. Without CAN, the wiring harness would be as big around as your leg with all of the wires needed to run the many components. CAN pares that harness down considerably which also reduces manufacturing costs. Almost all cars are using CAN and have been for a decade+. Polaris has been using it for over a decade. It's not new and it's not that complicated. It (like any electrical issue) can be a pain in the neck if you let it, though.

605 means the ecu is not seeing what it is expecting on the can line. Again, could be a broken wire, mouse eat wire, chipmunk nest, or a wire pulled out of a connector due to maybe a stick or something. Usually CAN lines on Kubota are green and yellow, twisted wires. Normally a pair, one green one yellow, and they are twisted together. So if you are under the hood, look around as best you can. If you can see a twisted green/yellow pair of wires and one or both of them is pulled out of a connector or chewed off, you may have found your issue.

There was a bulletin that outlined how to diagnose this code. It was in depth and it works. The usual cause in my case was either rodents or corrosion in the ECU connector.

 

[SkylineAcres16]

Update- So the tractor has been in the shop now for a couple of days and I received a call today from the dealer. They tried connecting 2 different laptops with different cables up to the tractor and could not get either laptop to talk to the ECU. Unfortunately, as I had figured the battery took out the ECU. The dealer quoted $2,700 for the ECU which doesn't include labor or the transportation of getting my tractor to/from the dealer. I told them I do not have 3+ grand laying around for this and I asked if KTAC would cover this. Their warranty guy was at another dealer location today and he said he would get back with me in a day or two because he himself wasn't sure. Now, I am faced with an over $3,000 decision to make. I'm even floating around the possibility of what would the trade-in value be compared to a new MX6000 since it's going to cost $3,000 just to fix my old one anyways. Well, there you have it guys. The working theory is the battery took out the ECU at an astronomical cost. I don't even know how somebody could try and prevent this from happening other than having luck on your side and hope your battery doesn't go out in this manner. I even told the dealer "So in theory, every 5 years when my battery goes out I could be faced with a $3,000 bill" and he really didn't know what to say about that. Obviously, as I said before, my battery mode of failure was probably a rare one but it obviously does happen and does end up costing you. Thanks.

 

[Fordtech86]

They tried connecting 2 different laptops with different cables up to the tractor and could not get either laptop to talk to the ECU.

If that’s all the diag that was done I would take it somewhere else…I realize that ain’t as easy with a tractor though.

 

[Pau7220]

They tried connecting 2 different laptops with different cables up to the tractor and could not get either laptop to talk to the ECU

If that’s all the diag that was done I would take it somewhere else…I realize that ain’t as easy with a tractor though.

It's not that complicated but it can be if you let it.

Agreed… In the automotive world a shorted CAN line may prevent any communication. Disconnecting components on the circuit one at a time until the defective one is found wakes up the communication. If the ECU turns out to be dead, so be it… but there are diagnostics to follow to be sure.

I still can’t believe they did this to off-road ag equipment

 

[Fordtech86]

Agreed… In the automotive world a shorted CAN line may prevent any communication. Disconnecting components on the circuit one at a time until the defective one is found wakes up the communication. If the ECU turns out to be dead, so be it… but there are diagnostics to follow to be sure.

I tried to find a free wiring diagram for the model but couldn’t. I can’t imagine the network is very complicated on that tractor. Few basic checks with a meter would help

 

[lugbolt]

Power surge can and does take out components.

I've seen it on multiple types of equipment.

They try to avoid it with the circuitry, diodes, caps, etc but they can never prevent all possible failures.

 

[SkylineAcres16]

For anyone that's interested or may be reading this in the future I found another thread from this forum dated about a year ago and it was from a guy with the exact same problem and exact same tractor (MX5800- he starts off saying M but if you read down he means MX) and the tractor was bought around the same time frame as mine (2016-2017) for what thats worth. He also states in the thread that his dealer said they have seen this on another occassion locally as well. Who actually knows but it would be interesting.

Fried ECU

Research and purchase M series Kubota in September of 2017. Works great. Love it. Off brand, “Made in Korea” battery installed at factory goes bad in 3.5 years. In response, alternator output goes sky high. No overcharge protection in unit. Error codes P0605, P0606, P0627, P0629 and others...

www.orangetractortalks.com

Anyways, his description of what happened is exactly what I experienced to the T. Even down to the cost of $2,700 to fix it is the same as I'm being told.

I am mainly posting this because most people in that thread say that they have never heard of this being a problem or he is the first one they have heard of, etc so now we can say it might not be common but there is evidence that it does happen and has happened more than once.

 

[SkylineAcres16]

Original poster here. So I just wanted to close the loop on this issue for anyone that was interested and also for anyone that may do a google search in the future. I know it has been over 2 months but it took that long for KTAC to go through their process and they ultimately denied the claim. You can see the letter attached. They also sent an Independent Adjuster to my dealer rather than taking my dealers word that it was due to water damage (water damage and flood damage are covered under KTAC). You can see the Independent Adjusters review of the issue attached as well. Ultimately, even though water damage is covered under KTAC and the ECU failed due to water damage (both parties agree on this; dealer and KTAC) the deciding factor came down to was it a gradual deterioration or did it happen quicky like an accident? They basically decided to say that since there was corrision on the plug pins (I honestly can't tell if it's corrosion or some type of dielectric grease) it happened over a period of time (see denial letter below) rather than a quick accident. Had I been pressure washing the tractor and got water in the ECU or something along those lines I believe it would have been covered.

I have a couple of points that I have been pondering over since the denial. About 3 weeks to a month before the ECU failed I was pushing snow during a snow storm. Let's say hypothetically some snow got under the dash and into the ECU plug. During the next month the tractor is in the barn sitting unused. It seems to me like 1 month of time is enough time for electrical corrosion to visibly show (think about battery terminals) but yet the problem doesn't rear itself until the next time I start the tractor and the ECU shorts out. My assumption with talking with KTAC was if I had started the tractor the next day or so and the ECU went out it would therefore be able to be tied back to the snow storm and would more than likely have been covered. But since I waited one month to start the tractor there was an issue of 'time' and KTAC doesn't cover gradual deterioration over time (again, see denial letter).

With all of that said I am not posting this because I am butt-hurt but instead 1) raising an issue that it seems like there is some gray area as far as what is considered 'over time' vs an immediate event happened that can be traced back to the causation (think pressure washer) and 2) How can I prevent this from happening in the future? If ECU water damage happened to my tractor I can 100% tell you it can happen to yours as well. My tractor lives inside a very nice pole barn out of the elements and it still looks new even though I bought it in 2016. Matter of fact, when tractors sit on dealer lots outside for months (I know this doesn't happen as much now with COVID supply issues) those tractors are experiencing 100X the amount of rain/water than my tractor has ever been subjected to. So the big question is "How do I make sure this doesn't happen again?"

Anyways tomorrow I will be getting my tractor back. It left my property 2-1/2 months ago and I am sure happy to be getting it back. I have a lot of work lined up for it. Like I may have said in other posts before if I had done something to my tractor to abuse it and crack a trans case, or run it out of oil, or anything crazy like that then I would take full responsibility. However, I think a water damaged ECU on a tractor that never is out in the elements for any amount of time and ending up costing me $3,000 is something to be a little upset about. I have babied this tractor more or less by doing maintenances right on schedule, using all Kubota oil/filters/parts, all of that.

If I haven't already mentioned the attached pictures are 1) a picture of the ECU pins that KTAC made their decision based on 2) KTAC denial letter 3) Independent Adjuster Letter to KTAC and 4) Final Invoice I ended up paying.

Thanks!

 

[PoTreeBoy]

Did you get the old one back?

Is the ECU itself not sealed? Seems like you could clean the pins and connector and be back in business.

I'd seal the ECU with silicone and use dielectric grease generously, myself.

 

[lugbolt]

I saw a few of them corroded, and still new-/never washed/etc.

When discussing it with other techs, we came to the conclusion that something had to have gotten into the ecu connector area either during manufacturing, or shipping the ecu to manufacturer, etc. Another thought we had was saltwater. They come from Japan and are shipped over here on a boat. We thought that maybe a few of them had gotten saltwater blasted somehow on the boat. We have no way to go back and verify that's what happened, just a theory. Normally it wouldn't show up right away, typically a good while after the tractor was used and/or stored on dealer lot. I had a couple that were corroded the day I Assembled the new tractors out of the crate, on those there was also other evidence of corrosion in other areas which threw up a red flag toward something external causing it. That's how we came up with the saltwater bath (or shower) theory. These were 3301's as I remember.

Regardless, it was a horrible issue, as sometimes a complete wire harness + ecu was the only way to fix them. I actually saved a good harness and was able to de-pin some of the wires and use them to fix customer issues rather than making them spend $1100 on a new harness. It was never any fun to have to do it either but it saved some headache for the customer.

Still beats a failed DEF injector on the SVL95's, it would leach def into the harness, which would get all the way to the ACU, so it ruined the harness, ACU and sometimes the ECU. Very expensive.