Attempting to Probe, Results in Error Code 9

So I have just wired my Z probe up again after a rebuild of my machine.

I am using grbl 1.1f, and picsender for machine control.

If I try to probe it returns “error code 9”. It does not pop up as a swperate alarm or error box though (I guess only picsender users may know what I mean)

I can not seem to find anything related to error code 9 in regards to grbl or picsender, so wondered if anyone has come across it before?


Just to clarify, the machine does not attempt to move when I try to probe Z, and immediately shows the error

These are error codes for the latest grbl release (ver. 1.1f). Did you home ($H) your machine first?

1 Expected command letter G-code words consist of a letter and a value. Letter was not found.
2 Bad number format Numeric value format is not valid or missing an expected value.
3 Invalid statement Grbl ‘$’ system command was not recognized or supported.
4 Value < 0` Negative value received for an expected positive value.
5 Setting disabled Homing cycle is not enabled via settings.
6 Value < 3 usec Minimum step pulse time must be greater than 3usec.
7 EEPROM read fail. Using defaults EEPROM read failed. Reset and restored to default values.
8 Not idle Grbl ‘$’ command cannot be used unless Grbl is IDLE. Ensures smooth operation during a job.
9 G-code lock G-code locked out during alarm or jog state.
10 Homing not enabled Soft limits cannot be enabled without homing also enabled.
11 Line overflow Max characters per line exceeded. Line was not processed and executed.
12 Step rate > 30kHz Grbl ‘$’ setting value exceeds the maximum step rate supported.
13 Check Door Safety door detected as opened and door state initiated.
14 Line length exceeded Build info or startup line exceeded EEPROM line length limit.
15 Travel exceeded Jog target exceeds machine travel. Command ignored.
16 Invalid jog command Jog command with no ‘=’ or contains prohibited g-code.
20 Unsupported command Unsupported or invalid g-code command found in block.
21 Modal group violation More than one g-code command from same modal group found in block.
22 Undefined feed rate Feed rate has not yet been set or is undefined.
23 Invalid gcode ID:23 G-code command in block requires an integer value.
24 Invalid gcode ID:24 More than one g-code command that requires axis words found in block.
25 Invalid gcode ID:25 Repeated g-code word found in block.
26 Invalid gcode ID:26 No axis words found in block for g-code command or mode which requires them.
27 Invalid gcode ID:27 Line number value is invalid.
28 Invalid gcode ID:28 G-code command is missing a required value word.
29 Invalid gcode ID:29 Work coordinate system commanded not supported.
30 Invalid gcode ID:30 G53 only allowed during G0 and G1 motion modes.
31 Invalid gcode ID:31 Axis words found in block while no command uses them.
32 Invalid gcode ID:32 G2/3 arcs require at least one in-plane axis word.
33 Invalid gcode ID:33 Motion command target is invalid.
34 Invalid gcode ID:34 Arc radius value is invalid.
35 Invalid gcode ID:35 G2/3 arcs require at least one in-plane offset word.
36 Invalid gcode ID:36 Unused value words found in block.
37 Invalid gcode ID:37 G43.1 dynamic tool length offset assigned to wrong axis.
38 Invalid gcode ID:38 Tool number greater than max supported value.

EDIT: BTW, these codes can be displayed in PicSender in the Grbl screen.


Hi John, thanks for that.

Yes I had homed the machine prior to attempting to probe. I think I may have found the cause though as I seem to have an intermittent short in the jack plug I had wired to my probe.

Thankfully I have a spare so will solder that on and try it again

Problem solved.

Replaced the dodgy jack and it’s working nicely