Sorry for the late reply, work have been bunkers lately.
So it turns out that the problem is probably a lose connection in the wire. I tried to switch the wire to the two Z-axis, but found out that there was not enough length in the wires to do this, then put them back in their respective stepper.... lo and behold, it is working again.
Definitely need to order new cables.
After 1½ years of printing, my printers z axis (1 of the dual z axis) suddenly starts to change direction during a move and sound noisy. The motor itself turns fine when turned off, so it does not seem to be mechanical. I have checked the connectors and they seem fine, but have not ohmed the wires yet. I have taken af video of the fail:
https://photos.app.goo.gl/RDm96iy9JxALrZ1a7
Is the driver fried?
The problem is i have a CR-10 S5, which means it can print 500x500mm prints... but it is impossible to get such a big surface flat enough, so i need the bed mesh to compensate for this (or tell me where i need to level the surface).
No heaters or hotends are turned on. But i added the B1 parameter and it did not help (it actually got worse, but i think thats just random error in the diviation, not because i added the B1):
G32 bed probe heights: 0.115 0.202 0.322 0.117 0.122 0.210 0.322 0.217 0.317 0.190, mean 0.214, deviation from mean 0.079
I halfed it once, with no result, but just for the fun of it, i did it again:
G32 bed probe heights: 0.178 0.280 0.183 0.288 0.155 0.207 0.293 0.183 0.288 0.165, mean 0.222, deviation from mean 0.055
A little bit better, but not acceptable: 0,123mm between the max and minimum. And know it is so slow that you barely can see it moving.
I have fitted my two printers (Creality CR-10 S5 & Tronxy X5s) with a BL Touch censor and Duet 2 Wifi. Same story for both printers, but i will only give example from one:
When i am running the following script:
M401
G30 P0 X250 Y250 Z-9999
...... (repeat 10x times probing in the same spot)......
G30 P09 X250 Y250 Z-9999 s1
i get the following result:
G32 bed probe heights: -0.275 -0.245 -0.130 -0.255 -0.265 -0.248 -0.255 -0.250 -0.220 -0.287, mean -0.243, deviation from mean 0.041
Is this acceptable? 0.16mm difference between the outliers is almost half the height of one filament layer.
Following settings have been used:
; Z-Probe
M574 Z1 S2 ; Set endstops controlled by probe
M307 H3 A-1 C-1 D-1 ; Disable heater on PWM channel for BLTouch
M558 P9 H5 F80 T2000 ; Set Z probe type to bltouch and the dive height + speeds
G31 P500 X-45 Y-5 Z0.35 ; Set Z probe trigger value, offset and trigger height
M557 X15:195 Y15:195 S40 ; Define mesh grid
Its the same story for the other printer, which makes me think that i am doing something wrong.
Ok i will update it. Shit i think you are right. I can see that i have an M584 call in there... but if i delete this, then my second z-axe dos not work.... any idea?
Your help is very appreciated 
Here are my z-axis homing code:
; homez.g
; called to home the Z axis
;
; Lift Z relatively to current position
G91
G1 Z2 F6000 S2
; split Z motor control to Z and U
; for it to work we have to show U (param P4) in the UI
M584 Z2 U3 P4
; Move Z and U down until the switches triggers
G1 S1 Z-205 U-205 F1000 S2
; back to combined axes and hidden U
M584 Z2:3 P3
; Back to absolute positioning
G90
; Tell the firmware where we are
G92 Z0
; lift Z after probing
G91
G1 Z3 F1000 S2
G90
;--------------- repeat slowly----------
; split Z motor control to Z and U
; for it to work we have to show U (param P4) in the UI
M584 Z2 U3 P4
; Move Z and U down until the switches triggers
G1 S1 Z-205 U-205 F50 S2
; back to combined axes and hidden U
M584 Z2:3 P3
; Back to absolute positioning
G90
; Tell the firmware where we are
G92 Z0
; lift Z after probing
G91
G1 Z10 F1000 S2
G90
Yes the machine works, i can home all axis. Its only G29 and i tried G32 and that does the same. But i was of the understanding that G29 should be used for mapping.
I have a Duet 2 Wifi that are running my Tronxy x5s 3d printer (CoreXY). It has dual Z-axis were the second is run with the extra extruder driver and E0 pin for its own end stop.
I have followed the tutorial on how to set up the BLTouch.
When given the "G30 S-1" it works perfectly. But once i call the "G29" for mapping of the bed it just slams the bed into my hotend and endstops (with high speeds i should add 
).
Does anyone have a clue what i am doing wrong? I am suspecting that it might have something to do with my dual z endstops?
Any help will be appreciated, thanks
____ Firmware_____
Firmware Name: RepRapFirmware for Duet 2 WiFi/Ethernet
Firmware Electronics: Duet WiFi 1.02 or later
Firmware Version: 2.02RC6(RTOS) (2018-12-15b2)
WiFi Server Version: 1.21
Web Interface Version: 1.22.5
config file__
; Configuration file for Duet WiFi (firmware version 1.20 or newer)
; executed by the firmware on start-up
;
; generated by RepRapFirmware Configuration Tool on Mon Jul 23 2018 19:43:29 GMT-0500 (Central Daylight Time)
; General preferences
G90 ; Send absolute coordinates...
M83 ; ...but relative extruder moves
M667 S1 ; Select CoreXY mode
; Network
M550 PTronxy X5S ; Set machine name
M552 S1 ; Enable network
M587 S"HomeBox-5240_2.4G" P"hg39gg72b" I192.168.1.187 J192.168.1.1 K255.255.255.0 ; Configure access point and IP addresses. You can delete this line once connected
M586 P0 S1 ; Enable HTTP
M586 P1 S0 ; Disable FTP
M586 P2 S0 ; Disable Telnet
;-----------------
M208 X0 Y0 Z0 U0 S1 ; Set axis minima
M208 X330 Y330 Z380 U380 S0 ; Set axis maxima
;DUAL Z
M584 X0 Y1 Z2:3 U3 E4 P3
; Endstops
M574 X1 Y1 Z1 U1 S0 ; Set active low endstops
; Z probe configuration
M307 H3 A-1 C-1 D-1
M558 P9 F100 H5 T2000
G31 X47 Y7 Z1.44 P25
M557 X50:330 Y20:310 S40 ; Define mesh grid
; Drives
M569 P0 S0 ; Drive 0 goes forwards
M569 P1 S0 ; Drive 1 goes backwards
M569 P2 S1 ; Drive 2 goes forwards
M569 P3 S1 ; Drive 3 goes forwards
M569 P4 S0 ; Drive 4 goes backwards
M350 X64 Y64 Z64 U64 E16:16 I1 ; Configure microstepping with interpolation
M92 X320 Y320 Z1600 U1600 E92.6:92.6 ; Set steps per mm
M566 X600 Y600 Z12 U12 E300 ; Set maximum instantaneous speed changes (mm/min)
M203 X30000 Y30000 Z1200 U1200 E3600 ; Set maximum speeds (mm/min)
M201 X2500 Y2500 Z500 U500 E2500 ; Set accelerations (mm/s^2)
M906 X1000 Y1000 Z800 U800 E1000 I50 ; Set motor currents (mA) and motor idle factor in per cent
M84 S2 ; Set idle timeout
; Heaters
M305 P0 T100000 B4138 C0 R4700 ; Set thermistor + ADC parameters for heater 0
M143 H0 S120 ; Set temperature limit for heater 0 to 120C
M305 P1 T100000 B4138 C0 R4700 ; Set thermistor + ADC parameters for heater 1
M143 H1 S280 ; Set temperature limit for heater 1 to 280C
; Fans
M106 P0 S0 I0 F500 H-1 ; Set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned off
M106 P1 S1 I0 F500 H1 T45 ; Set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned on
M106 P2 S1 I0 F500 H-1 ; Set fan 2 value, PWM signal inversion and frequency. Thermostatic control is turned off
; Tools
M563 P0 D0 H1 ; Define tool 0
G10 P0 X0 Y0 Z0 ; Set tool 0 axis offsets
G10 P0 R0 S0 ; Set initial tool 0 active and standby temperatures to 0C
; Automatic power saving
M911 S10 R11 P"M913 X0 Y0 G91 M83 G1 Z3 E-5 F1000" ; Set voltage thresholds and actions to run on power loss
; Custom settings are not configured