I am trying to implement new PID values to try and solve a heat creep issue. The Marlin command M301 and M304 do not get a response (example code below). M104, M503, and M303 all work. When I use M503 to view the current PID values, they also haven't changed. I am using a Monoprice Select Printer and Pronterface to communicate.
>>> M301 P20 I0.02 D250 SENDING:M301 P20 I0.02 D250 >>> M301 SENDING:M301 >>> M503 SENDING:M503 EPR:2 75 115200 Baudrate EPR:3 129 2822.120 Filament printed [m] EPR:2 125 2200571 Printer active [s] EPR:2 79 0 Max. inactive time [ms,0=off] EPR:2 83 360000 Stop stepper after inactivity [ms,0=off] EPR:3 3 80.0000 X-axis steps per mm EPR:3 7 80.0000 Y-axis steps per mm EPR:3 11 405.4591 Z-axis steps per mm EPR:3 15 200.000 X-axis max. feedrate [mm/s] EPR:3 19 200.000 Y-axis max. feedrate [mm/s] EPR:3 23 2.000 Z-axis max. feedrate [mm/s] EPR:3 27 40.000 X-axis homing feedrate [mm/s] EPR:3 31 40.000 Y-axis homing feedrate [mm/s] EPR:3 35 2.000 Z-axis homing feedrate [mm/s] EPR:3 39 20.000 Max. jerk [mm/s] EPR:3 47 0.300 Max. Z-jerk [mm/s] EPR:3 133 0.000 X home pos [mm] EPR:3 137 0.000 Y home pos [mm] EPR:3 141 0.000 Z home pos [mm] EPR:3 145 200.000 X max length [mm] EPR:3 149 200.000 Y max length [mm] EPR:3 153 180.000 Z max length [mm] EPR:3 51 1000.000 X-axis acceleration [mm/s^2] EPR:3 55 1000.000 Y-axis acceleration [mm/s^2] EPR:3 59 100.000 Z-axis acceleration [mm/s^2] EPR:3 63 1000.000 X-axis travel acceleration [mm/s^2] EPR:3 67 1000.000 Y-axis travel acceleration [mm/s^2] EPR:3 71 100.000 Z-axis travel acceleration [mm/s^2] EPR:0 880 0 Autolevel active (1/0) EPR:0 106 0 Bed Heat Manager [0-3] EPR:0 107 255 Bed PID drive max EPR:0 124 80 Bed PID drive min EPR:3 108 196.000 Bed PID P-gain EPR:3 112 33.000 Bed PID I-gain EPR:3 116 290.000 Bed PID D-gain EPR:0 120 255 Bed PID max value [0-255] EPR:3 200 96.000 Extr.1 steps per mm EPR:3 204 50.000 Extr.1 max. feedrate [mm/s] EPR:3 208 20.000 Extr.1 start feedrate [mm/s] EPR:3 212 5000.000 Extr.1 acceleration [mm/s^2] EPR:0 216 0 Extr.1 heat manager [0-3] EPR:0 217 230 Extr.1 PID drive max EPR:0 245 40 Extr.1 PID drive min EPR:3 218 7.0000 Extr.1 PID P-gain/dead-time EPR:3 222 2.0000 Extr.1 PID I-gain EPR:3 226 40.0000 Extr.1 PID D-gain EPR:0 230 255 Extr.1 PID max value [0-255] EPR:2 231 0 Extr.1 X-offset [steps] EPR:2 235 0 Extr.1 Y-offset [steps] EPR:1 239 1 Extr.1 temp. stabilize time [s] EPR:1 250 150 Extr.1 temp. for retraction when heating [C] EPR:1 252 0 Extr.1 distance to retract when heating [mm] EPR:0 254 255 Extr.1 extruder cooler speed [0-255] 
