Bad news big repair

[PILOON]

Gee, all so simple.
Get 12 VDC to the glow plugs, heat them for a bit and she'll start!

 

[LittleBill21]

Hay,

its pretty simple, find the hot wire at the glow plug rail if it has one. simply disconnect it. Does the tractor run? it probably will. Most sensors need 3 wires to actually monitor anything. if its a single wire, no monitoring.

generally the ecu will just short the ground side of the relay that sends the power, especially for a high load such as glow plugs.

it seems important to you to try to keep it factory. so you can test at the relay to see if power is at the relay, and if the computer is actually trying power it., if no power there. then check for ground /power at the glow plug pin at the computer. if no power is coming out at the ecu, you will prolly need a new computer/fixed computer, or just install a manual override. hell you don't even need new wire, prolly just have to power the relay control.

good luck.

 

[redman135]

I assume that derating occurs when the computer detects a fault. BUT will the computer RERATE if fault is fixed or is it a tech call out once derating occurs.
Querry: If ecu software is problem, will an "ecu flash" restore/update the corrpt software in the glow plug circut, or is problem physical damage on the circut board for kubota to be talking ecu replacement?
Had a JD 7430 that was running rough, it was given an "ecu flash" and the problem was fixed(somehow 2 injectors were mistimed).
good luck

 

[LittleBill21]

I assume that derating occurs when the computer detects a fault. BUT will the computer RERATE if fault is fixed or is it a tech call out once derating occurs.
Querry: If ecu software is problem, will an "ecu flash" restore/update the corrpt software in the glow plug circut, or is problem physical damage on the circut board for kubota to be talking ecu replacement?
Had a JD 7430 that was running rough, it was given an "ecu flash" and the problem was fixed(somehow 2 injectors were mistimed).
good luck

generally its just a transistor controlled circuit, they can be burned out, but repairing them is generally specialized.

 

[Hay Dude]

ECU repair was discussed and they do not offer repairs to them. Reflash? Sure, but no repairs.

Keeping the tractor factory is preferred before a switch is installed.
The more I think about this, the more it makes me think the ECU plug could be corroded. The Ford Superduty problems I had were similar.

 

[rScotty]

The ECU reads the air and water temp sensors and they are both part of the glow plug wiring circuit and it has been stated that if the relays are bypassed, the tractor derates itself.
So how do you bypass all that and “simply install a switch”?

Well, on the one hand you don't know. But we do have some clues. I just replaced a $3000 ECU on the JD. Symptoms were that the air and water gauges were reading way too high of a temperature but I checked the senders and the wiring with an ohmmeter and found them good. Both were linear & within range. But the ECU was somehow convinced that it was reading zero ohms from the senders - which corresponds to about 250F. I'm told that is a bad connection WITHIN the ECU case and cannot be fixed. A known JD problem. Parts are in stock. So shell out $3K....which I did.

But all that did was fix my guage readouts. The motor ran exactly the same before and after.

So the point of this is that if your Kubota ECU and senders are anything like the JD ECU and senders....which seems possible, AND as long as your cab temperature gauges are reading right I think you may be OK to "simply install a switch".

But the option I prefer is to install a block heater on a thermostat. Then you don't need glow plugs. See how long you can go with that ECU.
BTW, they gave me a few hundred dollars credit for the old ECU. So somebody is fixing them....
rScotty

 

[Hay Dude]

As soon as I can get the tractor off the range and back to the shop, I am going to check the wiring and ECU plug.
Then it’s decision time, but I’m not spending $6000 and that’s for sure.

 

[Jchonline]

Messicks new, not installed (if I found the correct part). Kubota: ASSY ECU (V61,KB, Part # 1H005-60204

I didnt see any on ebay right now, just the M-135GX board.

 

[rScotty]

On our JD the dealer (really good dealer) said the cause of JD ECU failure is sometimes the connector to the ECU, but more often because on early models the ECU is mounted in the engine compartment so sees a lot of heat cycles with fuel and oil fumes.

On later models they moved the same ECU into the cab and have zero failures. JD does offera wiring harness to move older ECUs into the cab. It's a pretty complex wiring loom with about 30 wires. $2000 for the part; more to install....

I said for $2k+ I'll leave the new one where it is. Dealer surprised me by saying then that I can expect to get about 5000 hrs or 10 years out of it. They've replaced enough ECUs on JD310s to not only know the symptoms, but can forcast the failure rate...
rScotty

 

[Hay Dude]

Messicks new, not installed (if I found the correct part). Kubota: ASSY ECU (V61,KB, Part # 1H005-60204

I didnt see any on ebay right now, just the M-135GX board.

If that’s correct, that’s better, but still not realistic.
They did quote me $6000 based on previous M125x replacement and they did seem to indicate they looked up a price for mine.

 

[John_Mc]

I assume that derating occurs when the computer detects a fault. BUT will the computer RERATE if fault is fixed or is it a tech call out once derating occurs.

This is exactly what I was wondering. What happens if you don't disconnect anything, just run an additional line to the glow plugs activated through a momentary contact push button switch (as noted, you'll probably need to run it through an appropriately rated relay, since most switches are not rated for that sort of current). You might even be able to run the alternate power (or alternate ground depending on how it's wired) direct to the existing relay coil. MAYBE the ECU will not be ble to sense this, and things will operate as desired. However, if the ECU gets confused and derates, will it stop derating once you stop manually powering the glow plugs? If so, no big deal. You don't really need maximum power when first starting and warming up your tractor anyway.

 

[Hay Dude]

This is exactly what I was wondering. What happens if you don't disconnect anything, just run an additional line to the glow plugs activated through a momentary contact push button switch (as noted, you'll probably need to run it through an appropriately rated relay, since most switches are not rated for that sort of current). You might even be able to run the alternate power (or alternate ground depending on how it's wired) direct to the existing relay coil. MAYBE the ECU will not be ble to sense this, and things will operate as desired. However, if the ECU gets confused and derates, will it stop derating once you stop manually powering the glow plugs? If so, no big deal. You don't really need maximum power when first starting and warming up your tractor anyway.

Unsure, but those are my exact questions.

 

[groundcover]

Definitely check all the harness connections and grounds, clean up and a dab of dielectric grease. A work around could be put in new glow plugs wired to a momentary switch and relay and leave the old ones hooked up to the ecu. Make them a little box to live in out of the way Under the hood. Should be way cheaper !

 

[K5lwq]

There is no way the ECU would know the glow plugs are disconnected. If there is any feedback to the ECU, and I highly doubt there is, it would have to be a sensor somewhere that is triggered by the heat of the glow plug. If they are wired to work on a new circuit they will produce heat and the ECU will be satisfied.

However we know they are not working now and no light so obviously the ECM is not concerned with the glow plugs.

Edit to add...The glow plugs are disconnected anyway after the relay kicks out. So what difference could it make if they are disconnected after the relay?

 

[Hay Dude]

There is no way the ECU would know the glow plugs are disconnected. If there is any feedback to the ECU, and I highly doubt there is, it would have to be a sensor somewhere that is triggered by the heat of the glow plug. If they are wired to work on a new circuit they will produce heat and the ECU will be satisfied.

However we know they are not working now and no light so obviously the ECM is not concerned with the glow plugs.

But on the other tractor they serviced, the ECU knew the GPs were out and set a code.

 

[K5lwq]

But on the other tractor they serviced, the ECU knew the GPs were out and set a code.

I edited the post. They are disconnected when the relay is no longer energized. That wire can not be the feedback. It is totally separate from the control side of the circuit.

 

[CADplans]

If you have to push a button to energize the glow plugs, hide the button,,
with the button hidden, that will make it MUCH harder to steal the tractor.

 

[not2old]

Correct!
And that’s another really strange thing.…The dealer took a look at what I had already done. I thought maybe they could shed a little more light on the problem, but they didn’t give me much more info.
However, they had an older M125X in with the same problem a few weeks ago. It had No glow plugs, but it DID show a code. They Ohmed everything and tried new sensors- no dice.
They suggested an ECU replacement and $6000 later, the older M125X had glow plugs again.
So the question is, why would the older, but similar size tractor throw a glow plug code, but mine doesn’t?

FYI: My GC2610 doesn't have all this stuff that's giving you problems but it did turn on a light that had no description in the owner's manual. The dealer didn't know so they called the factory. I was told my tractor did not support that light but on some other model it indicated a plugged air filter. I cleaned the air filter and the light went away.

 

[etpm]

There were a lot of posts here so I may have missed something you have already tested. If this is so then I apologize for being redundant. But maybe I didn't miss anything so here goes. Since the ECU cannot power the glowplugs directly it must power a relay. So the first thing to check is if this relay is getting power to the relay coil when the glowplugs are supposed to be energized. If the relay coil is not getting power then check the wires from the relay coil to the ECU. If the wires are OK then check for power right at the ECU. No power right at the ECU? Then maybe it's the ECU. If it is getting power to the relay coil then check power to the relay contacts. If no power to the relay contacts then find the problem in the wires coming from the battery that go to the relay. If there is power to the relay contacts but none coming out then the relay is bad. The relay contacts could be bad or the relay coil could be bad. Make all these checks relating to the relay at the relay. If there is power at the relay output then the problem must lie between the relay and the glowplugs.
If there is no power at the ECU where the wires from the relay go when the glowplugs should be energized then the problem is partly or wholly in the ECU. It is possible, though unlikely, that the ECU monitors the glowplugs even when they are not energized. To check this remove the wires from the glowplugs and run the tractor. If it runs the same as before then the best work around is to then leave the wires disconnected and wire in a relay and push button switch, as was mentioned previously. If the tractor does constantly monitor the glowplugs there is another work around, also involving a relay or two, that will energize the glowplugs while isolating the ECU during starting, but will restore the ECU back into the circuit once the glowplugs are de-energized. If need be I will draw up the fairly simple circuit and post it.
Eric

 

[jyoutz]

A heated garage option available?

Or a block heater?