M7040 PTO rpm gauge

[Erwin Quinn]

I have an M7040 open station, and when I press the button to switch the diaplay reading from hours to PTO rpm all I get is OFF. I can have the brush cutter hooked up and going and the display still says OFF. It used to work perfectly but just recently quit.

What and where could the problem be? Where is the sensor for the PTO actually located and if it were to be the problem, is it something I could replace?

Thanks

 

[KubotaTech]

Not sure but I think the sensor is on the side of the transmission, in the side of the case.

 

[ETRon]

The only switch I see on a quick look-see is the engagement switch that is located under the cover by the engagement lever itself. If the computer doesn't know the pto is engaged via this switch I'd imagine it could well cause the symptoms you're experiencing. The rest of the system is hydraulic over mechanical.

 

[caveman]

I have the exact problem as the person who originally posted this question. The switch by the pto lever seems to work. I bypassed it temporarily and the pto speed gauge would just say OFF when the pto was running. My pto will run with the clutch pedal depressed. The alarm will not sound now with the pto engaged and no weight in the seat either. The tractor is an open station M7040. If any of you have suggestions on other things to check, please let me know. Thank you, Caveman

 

[Tx Jim]

PTO should/will operate with foot clutch pedal depressed because pto is totally independent of traction clutch IE hyd controlled. PTO shaft would require a sensor to determine shaft speed so I think sensor is bad or wire is loose.

 

[caveman]

Thanks, TxJim. I will have to try locate the sensor.

 

[ETRon]

I'm not aware of a sensor for the pto itself and can't find one on either the service or parts manual. The only sensor of note is the travel sensor on the left side of the tranny. As near as I can tell the rpm display for the pto is just a computation by the processor off the engine speed sensor. Make sure you have the correct display mode selected, as a last thought, perhaps switch it back and forth between modes........

 

[Tx Jim]

I'm not aware of a sensor for the pto itself and can't find one on either the service or parts manual. The only sensor of note is the travel sensor on the left side of the tranny. As near as I can tell the rpm display for the pto is just a computation by the processor off the engine speed sensor. Make sure you have the correct display mode selected, as a last thought, perhaps switch it back and forth between modes........

You could be correct as I couldn't locate a pto sensor in a M7040 parts catalog or WSM either.

 

[caveman]

I have switched it between modes several times, disconnected and connected all of the wires between the pto switch, seat switch and even bypassed pto switch wires. The pto lever activates the shaft perfectly but it displays that it is in the off position on the pto rpm gauge. Also, the alarm does not sound when no weight is in the seat and the pto is running and it can be started with the pto engaged. There is a sensor on the left side of the transmission that will be easier to get out with the fuel tank removed. I guess I may do this next weekend and try to determine if it is the cause.
Thanks for the suggestions.

 

[Russell King]

You may want to disconnect the battery and let it sit for a while then reconnect - try to reset the "computer" and see if it fixes it.

 

[gpreuss]

I have switched it between modes several times, disconnected and connected all of the wires between the pto switch, seat switch and even bypassed pto switch wires. The pto lever activates the shaft perfectly but it displays that it is in the off position on the pto rpm gauge. Also, the alarm does not sound when no weight is in the seat and the pto is running and it can be started with the pto engaged. There is a sensor on the left side of the transmission that will be easier to get out with the fuel tank removed. I guess I may do this next weekend and try to determine if it is the cause.
Thanks for the suggestions.

Sounds like the PTO switch itself is bad, since you've checked all of the wiring. Put an ohm meter on the switch contacts and see if it is working.

 

[caveman]

I disconnected the battery for a few minutes today but nothing changed. The pto gauge still read OFF when the pto is in use. The pto switch was bypassed as one of the first attempts to determine the cause.

 

[mpmitch1]

I have the exact same problem. Is there a solution?

 

[mbu]

Is the PTO gauge fused?

 

[100 td]

Also, the alarm does not sound when no weight is in the seat and the pto is running and it can be started with the pto engaged.

This sounds like a lost PTO/safety circuit input, so perhaps the wires have rubbed through somewhere.
Send Dave_eng a PM, he has a 7040 and will have the service manual, and can have a look at the circuit. He may notice this thread depending on how many others move it down the list.

 

[mpmitch1]

i should clarify, I have a 3240 and am experiencing the same problem.

 

[100 td]

And I just noticed the comments are 3 years old!

 

[mpmitch1]

It was the PTO switch. I tapped it with a hammer and it started working correctly. Easy fix! Should be a cheap part