I have a John Deere 318G skid steer. The parking break will not disengage. Engine will start. The seat lever is down and light is off yet the parking break light will not go off when button is pushed. The first time this happened my son just turned it off and back on and it worked. Then while driving it kicked on and stopped him in his tracks, but it went off again and he was able to work. A few minutes later it came on and we have not been able to get it to go off since. Needing some direction on where to go from here as the manuals trouble shooting says to lower seat bar. It has active codes of JSR 3509.02, HCU2 661.07, and 2661.07.
Post your serial number to help the guys with factory labtops to access all the informatioon on your unit. Simon C
Here is the S/N 1T318GKHHJ321484
Welcome to HEF HalfaFarmer ! Those codes are active? 3509.02, I can't find. Double check that is the code you are seeing and post. The next 2 are repeats. Anyway, 2661.07 (Right Joystick "Y" Fault) will keep the machine from moving. The diagnostic procedure for that says to reprogram the controller (there is a newer version of software available for your machine), and, if that does not fix it, then replace the right joystick. 99% of the time, the software update does not fix it. Before I condemn a joystick, check that the voltage supply and ground are good at the joystick. It should have a 4 wire plug. Carefully backprobe the red wire to see if it has 12 volts. Then do the same with the black wire checking for 0.100 volts or less. The yellow wire should have approximately 2.6 volts (it will be a moving target for this one) and the green wire should have approximately 2.4 volts (again a moving target). Wiggle the wiring harness from the joystick all the way back to the hydraulic controller under the cab to make sure the voltages remain intact. If the voltage checks are good, then you need a joystick.
Bless you brother. I'm having the same issue. Your troubleshooting information was very helpful.