3046r PTO won't engage

Slick64 said:

Hi folks,

Before I go and order a new one, does anyone happen to know the correct resistance for these coils.

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My 4052R technical manual doesn't give a range of acceptable resistances for the PTO Solenoid, but my 4610 manual says to replace the PTO solenoid if the coil resistance is not in the range of 10.5 - 11.5 ohms or if either side of the coil is shorted to case ground.

On my 4052R, you can go into diagnostic mode and display the PTO solenoid coil current (parameter ICC 031) with the PTO turned on. Below is what is normal for my 4052R (~1.22 amps).


If the battery voltage was 12.5V with the tractor engine off when the above coil current was observed, the PTO solenoid coil resistance is about 12.5V/1.22A = 10.25 ohms.

JD Driver said:

My 4052R technical manual doesn't give a range of acceptable resistances for the PTO Solenoid, but my 4610 manual says to replace the PTO solenoid if the coil resistance is not in the range of 10.5 - 11.5 ohms or if either side of the coil is shorted to case ground.

On my 4052R, you can go into diagnostic mode and display the PTO solenoid coil current (parameter ICC 031) with the PTO turned on. Below is what is normal for my 4052R (~1.22 amps).

View attachment 797335
If the battery voltage was 12.5V with the tractor engine off when the above coil current was observed, the PTO solenoid coil resistance is about 12.5V/1.22A = 10.25 ohms.

Click to expand...

Thanks for the reply. I too can go into diagnostic mode on my 3046r. I will try it to see if I can get a reading as well.

I measured the resistance with the coil off the tractor and I am getting 11.2 ohms, but it just a cheap meter, so who knows what it actually is.

Slick64 said:

Thanks for the reply. I too can go into diagnostic mode on my 3046r. I will try it to see if I can get a reading as well.

I measured the resistance with the coil off the tractor and I am getting 11.2 ohms, but it just a cheap meter, so who knows what it actually is.

Click to expand...

JD Driver said:

My 4052R technical manual doesn't give a range of acceptable resistances for the PTO Solenoid, but my 4610 manual says to replace the PTO solenoid if the coil resistance is not in the range of 10.5 - 11.5 ohms or if either side of the coil is shorted to case ground.

On my 4052R, you can go into diagnostic mode and display the PTO solenoid coil current (parameter ICC 031) with the PTO turned on. Below is what is normal for my 4052R (~1.22 amps).

View attachment 797335
If the battery voltage was 12.5V with the tractor engine off when the above coil current was observed, the PTO solenoid coil resistance is about 12.5V/1.22A = 10.25 ohms.

Click to expand...

If someone with a 3r series, 4105, 3720, 3520 or 3203 could check theirs, that would be great. They are the only models that have the same coil (according to jdparts)
Thanks

Slick64 said:

Ok, I tried to check mine and I was getting a number that was counting down for parameter 031. So are the ICC parameters the same for different models? Does anyone have them for a 3046r?

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Can you give us some additional detail on what you did/saw?
For example:
1. Where did the PTO current start, and where did it end, and over what time period?
2. Was this data taken with the tractor engine off? Probably so, which is fine, but without the alternator helping out, everything is dependent on your battery voltage. If the battery voltage is dropping during your test, it would be normal for the PTO solenoid current to also be dropping. If you repeat this test, I would put a voltmeter on the battery so you can watch the battery voltage during the test.

Have you verified that your alternator is putting out ~14V, or a little higher, when the engine is running? You don't mention an error associated with low charge voltage, but if the system were trying to run with just the battery and no alternator, it would be expected that the system would error out after a short time of providing a lot of current to the PTO solenoid and dragging the battery voltage down.

Have you verified that there is no damage to the wiring or connector to the PTO solenoid? A poor connection to this solenoid could cause the system to report a PTO coil fault.

Well.....thanks again for the reply. I actually did the test the first time with the engine off, as I read in your post "If the battery voltage was 12.5V with the tractor engine off....". So I went out to try it again with the engine running.

I confirmed that I have 14.4V. But, the reading for parameter 031 starts out at about 3.50 +/- and drops about 0.01 per second. If I engage the pto while it is reading above 3.00, I get the pto coil fault error. If I wait until the number drops below 3.00, the pto will engage. But, the numbers then start to increase, and once it hits 3.00 again, it shuts off. I even waited until it reached 0.20 and engaged the switch. It ran as long as the amps climbed until it reached 3.00

So, I assume it has a safety feature that will shut it down if it is drawing more than 3 amps.

So, to determine if it is the coil, I unplugged it, but still had the high amp numbers.....Does this sound like a short somewhere or a bad ICC panel???

Slick64 said:

Well.....thanks again for the reply. I actually did the test the first time with the engine off, as I read in your post "If the battery voltage was 12.5V with the tractor engine off....". So I went out to try it again with the engine running.

I confirmed that I have 14.4V. But, the reading for parameter 031 starts out at about 3.50 +/- and drops about 0.01 per second. If I engage the pto while it is reading above 3.00, I get the pto coil fault error. If I wait until the number drops below 3.00, the pto will engage. But, the numbers then start to increase, and once it hits 3.00 again, it shuts off. I even waited until it reached 0.20 and engaged the switch. It ran as long as the amps climbed until it reached 3.00

So, I assume it has a safety feature that will shut it down if it is drawing more than 3 amps.

So, to determine if it is the coil, I unplugged it, but still had the high amp numbers.....Does this sound like a short somewhere or a bad ICC panel???

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Good job with the additional troubleshooting. It could have been a partial solenoid valve coil short to ground, but since you still see the high current when the PTO solenoid is disconnected, I would agree that you either have a wiring short, or there is a problem with the ICC.

With a wiring short, it is possible that the ICC is current limiting this output to prevent from burning out the wiring or blowing a fuse.

I would certainly start by unplugging the connector on the ICC and the connector on the PTO solenoid and check for continuity (short) to ground.

On my 4052R, the PTO solenoid is driven from pin G on the ICC A01 connector.

Hi all. i had a similar fault on my 3036E (note not "R") Aussie model. It turned out to be a high resistance joint. The ECU in the R model may work similar to mine. it takes a few seconds to engage as it starts at 7Volts and ramps up to 12volt by the addition of a variable width square wave imposed upon the 7volt rail. Th ECU measures the current and when it is inside the current window it maintains the pulse width ratio. If the resistance of the coil is low it might trigger an over current shutdown or as in my case it went to full 100% duty cycle and failed to reach minimum current and reported the coil fault. Corosion or grease in the joint or a poor crimp on the connector are places to look if the resistance of the coil looks good. My 2cents worth, hope it helps.


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So, I did the check that JD Driver mentioned. There is good continuity from the ICC connector pin and the coil connector pin. No continuity to ground, so no short there. With the coil unplugged and the ICC connected, I have 0.35 volts at the purple wire at the coil connector (key on). If I unplug from the ICC it goes away. So, it seams to be the ICC creating this somehow..... Not good news

Thoughts???

I wouldn't assume that having 0.35 volts on the ICC output terminal is a bad thing. The solid state coil driver output on the ICC may not rest at 0 volts.

Back at the PTO solenoid valve, did you check to make sure that neither pin on the solenoid valve connector shows any continuity to case ground?

Slick64 said:

I only checked the positive wire (purple). I guess I assumed the black would have continuity to ground....

I will check it, thanks

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Note that I wasn't talking about the wiring harness. This is a check of the solenoid valve itself to make sure than there is no current leakage to the solenoid case from either side of the coil.

Oh, yes. I checked that before, no short. I do still get the amperage increase & decrease with the solenoid coil unhooked.

I don't understand how the Icc can be giving an amperage reading if I have the connector unhooked. There is no path for the current to go....

I admit that I am limited in expertise on the matter, but I thought that current could only be measured if there was a load between + & -

Yes, since we don't really know how the ICC behaves when you unplug the PTO solenoid valve, I was just trying to get back to basics to try to make sure that all tests have been completed which might prove that the solenoid valve doesn't have a problem - even though the ICC is convinced that there is.

Agree that it doesn't make any sense that current could be flowing out of the ICC if there is no downstream connection to ground. In a perfect world, I would say to unpin that wire out of the ICC connector to absolutely remove any possible external current path, and see if the ICC stops reporting PTO solenoid current flow.

I certainly appreciate your help!!

Perhaps it does naturally throw out the crazy amperage readings when it is unhooked or faulty. If it wasn't going to cost me $350 to try a new solenoid coil (Canadian $$), I would try it.

I may just need to bight the bullet and order one......unless anyone has any other ideas - at this point I will try anything. Maybe there is a way to reset the icc?

Thanks again

Also, as a side note. I did unplug the coil, but left it attached to the solenoid, and connected to a 12v battery while the tractor was running. The pto ran fine. I just didn't have any pto speed output since the icc still reported a fault. So, the coil works, but maybe just not to the scale that the icc measures....?????

Ok, even though it is over 100 F in the barn today, I did some tests both with and without the PTO solenoid valve connected.

First, I was reminded that the ICC 031 PTO solenoid current readout means nothing when the engine is not running, even with the PTO switch pulled on - presumably because the system will not try to turn the PTO on (or even energize the PTO solenoid) if the engine is not running and making hydraulic pressure.

Here is the PTO current with the PTO solenoid plugged in, engine running, and the PTO turned off. It varied between 0.01A and 0.03A.


Here is the PTO current with the PTO solenoid unplugged, engine running, and the PTO turned off. Note that it reads higher than with the PTO solenoid plugged in, which makes no sense, but it is what @Slick64 also reported.


Here is the PTO current with the PTO solenoid plugged in, engine running, and the PTO turned on. This is normal PTO solenoid current (1.22A to 1.50A) for this tractor.


Here is the PTO current with the PTO solenoid unplugged, engine running, and the PTO turned on. Note that it correctly flagged the PTO solenoid fault within a few seconds. Also note that the current is the same as when the PTO was turned off, so it properly reported that there was no current flow to the unplugged PTO solenoid valve.


After this testing, I plugged the PTO solenoid valve back in, started up the tractor, and the PTO ran normally with no errors.

I was going to crawl under the tractor with my multimeter and measure the PTO solenoid coil resistance, but by the end of the above testing, I was dripping profusely, so I retreated back to the air conditioning.