MX5800 dies when rocking pedal forward or reverse (SOLVED)

[Worksmart]

MX5800 starts fine. Can be standing next to it or sitting on seat to start it. As soon as you rock the pedal to go forward or reverse, the engine cuts out. It will also quit when you turn on the PTO. Always restarts just fine. We've thrown a seat sensor at it and the pedal sensor found up under the dash. Neither part solved problem.

What part should we throw at it next? Trying to avoid loading on trailer and having it sit at the dealer for a month.

Thanks much

 

[ptsg]

I would revisit the seat switch. The seat might not be pressing hard enough on the switch to let it operate as it should.

 

[Worksmart]

We will definitely double check the seat switch activation but the question becomes why does it quit when you turn on the PTO? We've always been able to turn on the PTO either seated or when standing next to the tractor to start the feed grinder. To me that means the seat switch would not have to do with that situation.

You can be on the seat and rock the pedal or start the PTO and it cuts out.

 

[thclimer]

Does your parking brake have to be on if you are not in your seat and be able to run your PTO?

Do you have an electrical schematic for your MX5800?

I'm wondering if there is something other than just safety switches (PTO, Seat, Parking Brake...) more like a module which has failed but still allows you to start but not move or engage the PTO?

 

[Worksmart]

Does your parking brake have to be on if you are not in your seat and be able to run your PTO?

Do you have an electrical schematic for your MX5800?

I'm wondering if there is something other than just safety switches (PTO, Seat, Parking Brake...) more like a module which has failed but still allows you to start but not move or engage the PTO?

No, the parking brake does not have to be on to run the PTO.

No electrical diagrams. Just using parts diagrams to trace parts.

I was in fact starting to wonder if it is a possible failure in the ECU. All of the safety components meet at the ECU as best I can tell looking the the wiring harnesses on the parts diagrams. There doesn't appear to be any real mechanical linkages for the safety components.

 

[thclimer]

Is this the sequence you have to use the PTO if your not in the seat:

 

[thclimer]

I'm having a hard time believing your ECU has failed for just this "safety" issue, that would be very unfortunate.

Hopefully someone with more familiarity about your tractor can help.

 

[Worksmart]

Thanks for the PTO sequence diagram. The thing is with this tractor we've always been able to simply start the tractor and then the PTO standing next to it. No parking brake needed. No flipping the seat forward. We run both a feed grinder and a hay bale elevator from the PTO. The tractor was purchased used and there is no sign anyone bypassed any safety features.

I hope it isn't the ECU because it ain't cheap. That's for sure.

 

[thclimer]

That sure does seem strange that something has changed with how you used to be able to operate your PTO and especially now you can not move the tractor without it shutting off.

 

[thclimer]

Is your seat switch just a simple switch? If so I'd just connect the wires together.

Can you follow the seat switch wiring to make sure its not damage or chewed?

Is there any sensor/switch that lets the tractor know that the seat is flipped up as is described in the PTO sequence?