# BLTouch error causing bed and nozzle temp setpoints to change to zero

I replaced my CR-10 motherboard with no problems and ran fine for a few weeks, then decided to add a BLTouch. BLTouch was enabled from the config.h during compile.

I had heating issues at first but eventually figured out I had the thermistors plugs swapped on the motherboard. In the past, I never used start and stop G-codes because I only printed printer upgrades off of Thingiverse while learning to print. My prints weren't starting until I learned more about G-codes and added G29 and G29 to my Cura start codes.

I tried a piece that I've printed before because I knew it worked ok. I preheated the bed and nozzle first, then started the print. The G28 initiates and homes, then the G29 does the 9 point bed leveling, then just sits there and does nothing.

## BLTouch behavior during the process

• BLTouch moves to "home" from center, with probe up and red light
• With the light still remaining red, BLTouch goes back to the center
• The BLTouch light turns blue once at the center, and drops the probe and lowers until probe touches and the light turns red
• Then raises again and the light turns blue, lowers again until probe touches bed then the light turns red again
• The light stays red and raises Z axis a little - and stays at center, still red
• The probe stays at center and red until reaching preheating temps
• After selecting file the probe moves to 9/9 points, with probe raised and blue light (drops probe and lowers until touching and turns red, then raises and turns blue)
• Once the last probe location is checked, BLTouch is still red and temperature settings from project file are set and heating starts
• The setpoints of bed and nozzle are reached (successfully heated)
• After heating, the setpoints switch to zero and temps start dropping towards the zero set point (cooldown) and never moves after that and shows status "Stopped"

## Pronterface - manual attempts

I connected through Pronterface so I could see the exact details. When I run a G28, from Pronterface:

• It goes to lower corner and is still red
• Returns to the center, probe drops and turns blue
• A few seconds later it drops until touching the bed and turns red
• Raises up again and turns blue, then drops BLTouch again until it touches the bed and turns red
• Then raises up again, but stays red this time
• I get an error in Pronterface "Stop called because of BLTouch error - restart with M999".

After it levels 9/9 points1, Pronterface shows a BLTouch error, the printer display shows print stopped, and the bed and nozzle setpoints had changed to zero. They both had already started cooling. I kept the start code simple just enough to get the print going.

I have no idea what the BLTouch error is but just that it caused two temperature settings to go to zero. Any help would be great!

1 The 9/9 points I'm referring to is when I run G29 and my config has 3x3 grid option selected so the G29 probes 9 points total with the BLTouch.

• Temperature is reset because printer (emergency) stops the print, I bet it is not correlated to the G29 procedure. Please describe behaviour of the BT light during and after the process. How did you enable BL-Touch? from LCD? – octopus8 Feb 14 at 19:12
• @Greenonline Not sure how to close this but I managed to figure it out, decided to try moving the Z-axis wires from the BLTouch plug on the motherboard and plugged them into where the printers Z-axis wires plug in and that solved the problem. No more errors and the print continues now instead of shutting down after the G29 command. – rsadler Feb 20 at 17:53
• It's great that you've found an answer. Please post that as an answer, and mark it as accepted (you may have to wait a few hours before you can accept it). This will then remove your question from the unanswered queue (which we need to keep as short as possible because we are a beta site). Thanks. – Greenonline Feb 20 at 21:59