Kx040-4 code 065

My kx040-4 is showing 065 in top right corner of display as well as flashing yellow warning light, now it’s in limp mode, any suggestions as to the problem

I have found a code 8 which the manual says is, intake pressure sensor system. what is that, only sensor I found in intake from breather is mass airflow sensor, I unplugged it and it gave a different code. Any help?

I forgot to add that this is an engine system error

The Kubota KX040-4 error code 065 generally indicates a hydraulic pressure sensor malfunction or a related wiring issue. It is often accompanied by engine system errors (Limp Mode) caused by issues in the aftertreatment system, specifically related to DPF (Diesel Particulate Filter) pressure or temperature sensors. Top Causes and Troubleshooting Steps Check Hydraulic Sensor: Inspect the hydraulic pressure sensor and its wiring connectors for damage, corrosion, or loose connections. DPF System Issues: The code is frequently linked to DPF clogging or faulty exhaust sensors, leading to limp mode. Check Wiring Harness: Check the wiring harness continuity to the engine control module (ECM). Clear Codes: After inspecting or repairing, use a diagnostic scanner to clear the codes to see if it fixes the issue. Potential Fixes Clean/Replace Sensor: Cleaning or replacing the affected hydraulic sensor often resolves the 065 code. Check Fuel System: Clogged fuel filters can also trigger engine system errors. Drain water from the separator and replace fuel filters if necessary. Perform Forced Regeneration: If the issue is DPF-related, a parked regeneration may be necessary.

Allan M said: The Kubota KX040-4 error code 065 generally indicates a hydraulic pressure sensor malfunction or a related wiring issue. It is often accompanied by engine system errors (Limp Mode) caused by issues in the aftertreatment system, specifically related to DPF (Diesel Particulate Filter) pressure or temperature sensors. Top Causes and Troubleshooting Steps Check Hydraulic Sensor: Inspect the hydraulic pressure sensor and its wiring connectors for damage, corrosion, or loose connections. DPF System Issues: The code is frequently linked to DPF clogging or faulty exhaust sensors, leading to limp mode. Check Wiring Harness: Check the wiring harness continuity to the engine control module (ECM). Clear Codes: After inspecting or repairing, use a diagnostic scanner to clear the codes to see if it fixes the issue. Potential Fixes Clean/Replace Sensor: Cleaning or replacing the affected hydraulic sensor often resolves the 065 code. Check Fuel System: Clogged fuel filters can also trigger engine system errors. Drain water from the separator and replace fuel filters if necessary. Perform Forced Regeneration: If the issue is DPF-related, a parked regeneration may be necessary. Click to expand... Be honest, did you use AI to generate that for you? I don't have a KX040-4 book in front of me but I believe some of that information is not correct...

MG84 said: Be honest, did you use AI to generate that for you? I don't have a KX040-4 book in front of me but I believe some of that information is not correct... Click to expand... Yes. No one had responded to your thread. I thought this quick AI search might help your effort. The limp mode is ECM triggered to protect the engine/hydraulic systems when a sensor error pops up. I haven't gone through the WSM (Kubota mechanic's workshop manual as of yet. Which I have for reference.) Hydraulic pressures (generally low), fuel not feeding correctly (also low pressure), any ECM sensor failure for sure can trigger the limp or 50% power mode to protect the excavator. The most obvious to me with the 065 code is something with the DPF system (which happened to my neighbor with a KX057). You might try a forced regeneration and see if that fixes the issue--assuming no obvious fuel or electrical problems (mice chewing through wires which has happened to me). Net, net, I hope it's not something that requires extensive diagnostics. AI will source from the WSM mechanics manual if you ask the right questions--so it's a helpful source and will only get better over time. For example, here is how to test the MAF Sensor according to a quick AI search. It seems to be similar in the info in the WSM: To test a Mass Airflow (MAF) sensor on a Kubota KX040-4 excavator, check for Error Code 19, inspect for loose wiring, and use a multimeter to check for 12V power/ground at the connector. With the engine running, back-probe the signal wire to see if voltage increases smoothly with RPM. Clean with MAF cleaner if readings are low. Oh, one other thing, you can do a "hard reset" of the ECM by disconnecting the battery for about 15 minutes. When you reboot it will wipe the error codes. That way if the error was a fluke or you fixed the issues by touching a loose wire or sensor connection ...reestablished the connection then you're home free. Just a thought. All of us that do wrenching also know that intermittent mechanical issues are the worst! And, these will occur at the most inconvenient times. Best, in your endeavor. If my message isn't helpful then just ignore it.

The engine system error message is on the machine console, #065 is in top right of console, if I hit the info button it shows #8, the Kubota workshop manual I have states engine system errors are numbered 1-64, and #8 is intake pressure sensor system.

So, I personally would: 1) look for corroded wiring or broken wires in that circuit, 2) test to see if the sensor is working correctly, 3) check for any air leaks between the turbocharger and the intake manifold which would lead to a low boost pressure... and 4) do a hard reset of the ECM and see if that gets it. Maybe someone on this site has also experienced a similar issue and has not shared their experience as of yet.

I unplugged the MAF sensor as well as the pressure differential sensor on DPF and each one gave me the corresponding codes for that sensor, cleared codes and the #8 code still came back, disconnceted the battery for about 30 minutes, cleared code and still #8 comes back. It's still showing code# 8, it's not in limp mode right now, just did that once.

Can't figure out how to do a forced regen on this machine, can you tell me how?

I still don't know what intake pressure system is, is that the MAF sensor, maf shows a different code than what i'm getting

I have a conversation scheduled tomorrow afternoon (Monday) with a 25 year Kubota mechanic regarding installing a case drain on my U55-4. I've already given him a heads up that I'd like to pick his brain on your situation. I'll pass the notes from that conversation on to you tomorrow. Maybe he will have some good insights.

I just talked with my mechanic. Here are his general comments: He has never had to replace a MAF sensor. More than likely mice have chewed through a wire somewhere so the ECM isn't getting the correct signal. Kubota connectors are generally very good--so it's unlikely that it's a connector not making contact (corroded). He noted that it's highly unlikely that you have a air leak anywhere between the turbo charger and intake manifold. With these engine error codes a DPF cycle can't occur if needed and a forced DPF cycle needs a scanner to trigger it. Even then, no DPF cycle will occur until the MAF sensor code is resolved since it tells the ECM volume of air throughput which then determines fuel mixture regulation. A DPF cycle requires fuel mixture variation to heat up the engine exhaust. Bottom line: look for a chewed sensor wire. If you can't find that then he suggests to get a mechanic to put a scanner on the excavator to fully read all the data values/voltages, etc...from the various sensors. Hope this helps.

Allan M said: Yes. No one had responded to your thread. I thought this quick AI search might help your effort. Click to expand... First off, I'm not the OP, this isn't my thread. Second, I really question your statement about AI using the Kubota WSM's for reference. How and where is it getting this (copyrighted) information? Last I checked Kubota doesn't publish the WSMs for free on the web and they are not cheap to purchase at a dealer. Are you feeding it pirated pdf copys of the WSM? If so that in itself brings up some serious ethical questions. If not it's just using information it's gathered from the web, junk in = junk out. The AI has no idea what information is right and what is wrong, it just summarizes it and spits it back out. Please stop posting this AI drivel, the vast majority of users come here to get real information from real people with experience.

Allan M said: Yes. No one had responded to your thread. I thought this quick AI search might help your effort. The limp mode is ECM triggered to protect the engine/hydraulic systems when a sensor error pops up. I haven't gone through the WSM (Kubota mechanic's workshop manual as of yet. Which I have for reference.) Hydraulic pressures (generally low), fuel not feeding correctly (also low pressure), any ECM sensor failure for sure can trigger the limp or 50% power mode to protect the excavator. The most obvious to me with the 065 code is something with the DPF system (which happened to my neighbor with a KX057). You might try a forced regeneration and see if that fixes the issue--assuming no obvious fuel or electrical problems (mice chewing through wires which has happened to me). Net, net, I hope it's not something that requires extensive diagnostics. AI will source from the WSM mechanics manual if you ask the right questions--so it's a helpful source and will only get better over time. For example, here is how to test the MAF Sensor according to a quick AI search. It seems to be similar in the info in the WSM: To test a Mass Airflow (MAF) sensor on a Kubota KX040-4 excavator, check for Error Code 19, inspect for loose wiring, and use a multimeter to check for 12V power/ground at the connector. With the engine running, back-probe the signal wire to see if voltage increases smoothly with RPM. Clean with MAF cleaner if readings are low. Oh, one other thing, you can do a "hard reset" of the ECM by disconnecting the battery for about 15 minutes. When you reboot it will wipe the error codes. That way if the error was a fluke or you fixed the issues by touching a loose wire or sensor connection ...reestablished the connection then you're home free. Just a thought. All of us that do wrenching also know that intermittent mechanical issues are the worst! And, these will occur at the most inconvenient times. Best, in your endeavor. If my message isn't helpful then just ignore it. Click to expand... First off, I'm not the OP, this isn't my thread. Second, I really question your statement about AI using the Kubota WSM's for reference. How and where is it getting this (copyrighted) information? Last I checked Kubota doesn't publish the WSMs for free on the web and they are not cheap to purchase at a dealer. Are you feeding it pirated pdf copys of the WSM? If so that in itself brings up some serious ethical questions. If not it's just using information it's gathered from the web, junk in = junk out. The AI has no idea what information is right and what is wrong, it just summarizes it and spits it back out. Please stop posting this AI drivel, the vast majority of users come here to get real information from real people with experience.

MG84 said: First off, I'm not the OP, this isn't my thread. Second, I really question your statement about AI using the Kubota WSM's for reference. How and where is it getting this (copyrighted) information? Last I checked Kubota doesn't publish the WSMs for free on the web and they are not cheap to purchase at a dealer. Are you feeding it pirated pdf copys of the WSM? If so that in itself brings up some serious ethical questions. If not it's just using information it's gathered from the web, junk in = junk out. The AI has no idea what information is right and what is wrong, it just summarizes it and spits it back out. Please stop posting this AI drivel, the vast majority of users come here to get real information from real people with experience. Click to expand... Since your not the OP and you've inserted yourself here I suggest you read the thread carefully. Yes, I did an AI search. I did check it against the WSM for Kubota excavators that I possess. The manual is not real helpful. The AI input scans anything available online (in this case WSM material and/or inkind material was sourced from Orange Tractor Talk, Kubota manuals (it didn't say which ones), and material that sits somewhere online in the ether, and two other sites that are tractor/but not excavator specific (the search showed references). AI value depends on how one asks the question and refines the question. It seemed generally okay. I also took the time to speak today with a very experienced Kubota mechanic that works for a Kubota dealer (see input above). He shared his thoughts that will hopefully help this guy out. If you have something to contribute that might help DavisGravel do so. All of us that do wrenching know that some of these issues can be complex to figure out--and a big part of it is getting to know the machine and its idiosyncrasies. Even a clogged fuel filter could generate a code 8 and put this machine in a limb mode. (since fuel flow is part of the equation that the ECM is reading in combination with manifold pressure and air feed). Hopefully, one of ideas hear will help the situation. Worst case, unless someone on the Heavy Equipment Forum has dealt with this specific issue and has a pinpoint trouble shooting technique to try a scanner might be needed to read what the ECM is responding to. A thought on that: I cut a deal with this full time Kubota mechanic to moonlight periodically. He swings by my place and spends an hour or so double checking all of the maintenance I perform on my Kubota tractor and excavator. It's been a very cost-effect way for me to become a good equipment maintainer. I use my equipment in very hilly, treed, dangerous terrain. So, I'm trying to prevent breakdowns and accidents. Best regards, Allan

Thanks again for the info, still trying to track down the issue, still able to use the machine at this point

Hey davisgravel: One last thought. When I spoke with my Kubota mechanic he said, "Buy a diagnostic tool. You don't need one with all of the bells and whistles that I have (several thousands of dollars) because you're only going to use it on one specific machine." I did a search and found an Australian based company that sells the diagnostic tool (error code reader, manual, connector cable, capable of resetting the ECM and live monitoring) for under $300. I just ordered one. I figured that since I have about $50k invested in my excavator this is a reasonable investment to protect my investment. Hope you resolve your issue quickly. A https://www.repairmanuals.co/produc...WAIPrXc7RoCRmgQAvD_BwE&variant=49539195175189

Thanks for that info, sounds like something I need.

Problem finally solved, found broken wire where one of the wire loom clamps attaches the wiring to the bracket on top of engine. Once again thanks for all the help