Allow me to reuse this topic, I enabled jam debug with M602 S1 P1 but there's no output on console and many communication timeouts.
Comm errors stops when I disable debug (M602 S0 P1).
I'm using 1.0.4dev
14:04:41.744: N5197 M602 S1 P1
14:04:41.903: ok 5189
14:04:41.904: N5198 G1 X155.093 Y125.838 E54.1681
14:04:45.185: ok 5190
14:04:45.271: ok 5191
14:04:45.271: N5199 M117 ETA 14:34:10 day 7
14:04:48.744: ok 5192
14:04:48.744: N5200 G1 X199.356 Y170.101 E56.6665
14:04:48.949: ok 5193
14:04:48.949: N5201 G1 X199.370 Y169.539 E56.6890
14:04:48.954: ok 5194
14:04:48.954: N5202 G1 X199.360 Y169.426 E56.6935
14:04:52.427: ok 5195
14:04:52.427: N5203 G1 X155.093 Y125.159 E59.1921
14:04:52.427: N5204 G1 X155.093 Y124.480 E59.2192
14:04:52.513: ok 5196
14:04:52.513: N5205 G1 X199.293 Y168.680 E61.7140
14:04:56.228: ok 5197
14:04:56.228: N5206 M117 ETE 00:29:15
14:05:26.376: busy:processing (15)
14:05:27.597: Jam debugging:1
14:05:27.601: Info:Marked all extruders as unjammed.
14:05:27.601: Jam control disabled:1
14:05:27.700: ok 5198
14:05:27.700: ok 5199
14:05:27.701: N5207 M117 ETA 14:34:18 day 7
14:05:27.802: ok 5200
14:05:27.802: ok 5201
14:05:27.802: ok 5202
14:05:27.802: ok 5203
14:05:27.802: ok 5204
14:05:27.803: N5208 G1 X199.226 Y167.934 E61.7439
14:05:27.803: N5209 G1 X155.093 Y123.802 E64.2350
14:05:27.803: N5210 G1 X155.093 Y123.123 E64.2620
14:05:27.803: N5211 G1 X199.159 Y167.188 E66.7493
14:05:27.804: N5212 G1 X199.093 Y166.461 E66.7784
14:05:27.805: ok 5205
14:05:27.806: ok 5206
14:05:27.806: N5213 G1 X199.089 Y166.439 E66.7793
14:05:27.806: N5214 G1 X155.093 Y122.444 E69.2626
14:05:27.904: ok 5207
14:05:27.904: N5215 G1 X155.093 Y121.765 E69.2897
14:05:28.011: ok 5208
14:05:28.011: Error:Wrong checksum
14:05:28.011: N5216 G1 X198.911 Y165.583 E71.7629
14:05:28.015: ok 5209
14:05:28.015: ok 5210
14:05:28.015: ok 5211
14:05:28.015: ok 5212
14:05:28.016: ok 5213
14:05:28.016: N5217 M532 X5.3887 L4
14:05:28.016: N5218 G1 X198.733 Y164.726 E71.7979
14:05:28.016: N5219 G1 X155.093 Y121.086 E74.2611
14:05:28.016: N5220 G1 X155.093 Y120.407 E74.2882
14:05:28.017: N5221 G1 X198.555 Y163.869 E76.7413
14:05:28.018: Error:Wrong checksum
14:05:28.019: Resend:5214
14:05:28.030: ok
14:05:28.030: Error:Wrong checksum
14:05:28.030: Resend: N5214 G1 X155.093 Y122.444 E69.2626
14:05:28.030: Resend: N5215 G1 X155.093 Y121.765 E69.2897
14:05:28.039: ok 5214
14:05:28.039: ok 5215
14:05:28.039: Resend: N5216 G1 X198.911 Y165.583 E71.7629
14:05:28.040: Resend: N5217 M532 X5.3887 L4
14:05:28.043: ok 5216
14:05:28.043: Resend: N5218 G1 X198.733 Y164.726 E71.7979
14:05:28.047: ok 5217
14:05:28.047: ok 5218
14:05:28.048: Resend: N5219 G1 X155.093 Y121.086 E74.2611
14:05:28.048: Resend: N5220 G1 X155.093 Y120.407 E74.2882
14:05:32.054: Warning: Communication timeout - resetting communication buffer.
14:05:32.054: Connection status: Buffered:38, Manual Commands: 0, Job Commands: 5000
14:05:32.054: Buffer used:38 Enforced free byte:19 lines stored:2
14:05:32.054: Resend: N5221 G1 X198.555 Y163.869 E76.7413
14:05:32.055: N5222 G1 X198.465 Y163.435 E76.7590
14:05:35.625: ok 5219
14:05:35.695: ok 5220
14:05:35.695: N5223 M117 ETE 00:28:40
14:05:35.711: ok 5221
14:05:35.711: N5224 G1 X198.299 Y162.934 E76.7801
14:05:35.712: N5225 G1 X155.093 Y119.729 E79.2188
14:05:39.717: Warning: Communication timeout - resetting communication buffer.
14:05:39.717: Connection status: Buffered:38, Manual Commands: 0, Job Commands: 5000
14:05:39.717: Buffer used:38 Enforced free byte:19 lines stored:2
14:05:39.717: N5226 G1 X155.093 Y119.050 E79.2459
14:05:39.717: N5227 G1 X197.962 Y161.919 E81.6656
14:05:43.560: ok 5222
14:05:43.621: ok 5223
14:05:43.621: N5228 M117 ETA 14:34:07 day 7
14:05:43.723: ok 5224
14:05:43.724: N5229 G1 X197.626 Y160.904 E81.7082
14:05:43.724: N5230 G1 X155.744 Y119.021 E84.0723
14:05:47.727: Warning: Communication timeout - resetting communication buffer.
14:05:47.727: Connection status: Buffered:38, Manual Commands: 0, Job Commands: 5000
14:05:47.727: Buffer used:38 Enforced free byte:19 lines stored:2