Tractor Repair: mx 120 pto will not engage, lever type, key switch

Question
hello mx120 pto will not engage it will not give me a code when i do the code check it just keeps flashing on and on any ideas i tried jiggling the wires on seat and a jump wire on seat sensor didn't help-it worked when i shut if off yesterday thank you alex

Answer
Hello,

  If you are not touching the seat and turn on the pto switch and then the key switch, it should show any codes there, and if there are none, the light should stop blinking.  Any time you try to retrieve codes and the light just keeps blinking at a steady rate, the pto switch is at fault and is not only preventing the pto from working, but also is not allowing you to get into code retrieval mode.  This is a pretty common problem.  There are 2 types of pto switches used on these.  If you have the lever type switch, check the magnet on the lever to make sure it's in place and clean off any metal filings that are stuck to it.  If you have the knob type switch, those fail quite often so just replace it.  Once you get the switch working, you will be able to find out if there are other problems.  You will need to erase the codes that are already there.  To erase the codes, get into code retrieval mode and after each code is displayed, turn the pto switch off and on to show the next code.  Keep doing this until the light quits flashing codes which means you have reached the end of the code list and have displayed them all.  Then turn the switch off and on 3 times very quickly, ending up with the switch in the on position again.  The light should blink once, meaning the codes have been erased.  If the pto still does not work, check the codes again to see if any have returned since they were erased, and troubleshoot those.

                       Good luck,

                             Arnie

P.S.  If the seat sensor or wires fail, the yellow neutral light will flash and the tractor won't move when the F-N-R lever is taken out of neutral and put in gear.  The wires behind the seat break quite often from constantly bending while the seat suspension is bouncing up and down.