Can't complete Bed PID autotune

MarcoZ76

Hi,
i installed few days ago the repetier firmware ( online tool) 0.92.X
I have a Geeetech Delta G2 pro with geeetech GT2560 motherboard.
My problem is now when i try to compile the firmware with Arduino 1.8.0 ( Mac OSX) it said there is too low memory available (813 kb) and there could be a data trasmission errors, but i can upload it to my printer.
Then i tried to find the PID value of my thermistor bed with M303 P3 S60 but after reach the temperature something wong and there are some problem connection and the temperature still goes up untill 100°C so i need to close connection with the printer ( i use Repetier host) and reconnect it again. Before with Marlin firmware i never had this such of problem
Can you help me to sove the problem?
Thanks

Repetier

M303 P<extruder/bed> S<printTemerature> X0 R<Repetitions>- Auto detect pid values. Use P<NUM_EXTRUDER> for heated bed. X0 saves result in EEPROM. R is number of cycles.

so you have 3 extruders?

What does the log say? Most problems show up there so you get an idea what is going wrong.