How to troubleshoot brake sensor errors Follow

Symptoms

• Both Throttle and PAS do not work 
• Error 37 on Stunner LT 
• Error 03 Bafang motors, Stunner, Stunner X, Juggernaut Classic, Juggernaut Classic HD, Juggernaut Ultra, Juggernaut Ultra FS
• This symbol is staying on screen after brakes are released 

How to check

• Follow wires coming from brake sensor and unplug both left and right and see if symptoms disappear
• If so, plug in one and check if the error/symptoms return 
• repeat on the other side to confirm which brake is the cause 

Solutions 

Mechanical Brakes

• Make sure levers are returning to original position freely 
  • 

    If Bad

    • A brake adjustment is a necessary DIY found here

If Good

• Tektro
  • Adjust Brake sensor alignment screw 
    
    • Loosen set screw
      
    • Loosen adjustment screw 1/2 turn
      
    • Check if this fixes symptoms but brake sensor still activates and repeat with smaller adjustments 
      • Looser trips cutoff with more brake pressure
      • Tightening trips cutoff with less brake pressure
• Other
  • Remove lower cover 
  • Check for physical blockage and smooth movement of switch 
  • If neither fixes contact support for replacement

Hydraulic

• Tektro
  • Adjust Brake sensor alignment screw 
    
    • Loosen set screw
      
    • Loosen adjustment screw 1/2 turn
      
    • Check if this fixes symptoms but brake sensor still activates and repeat with smaller adjustments 
      • Looser trips cutoff with more brake pressure
      • Tightening trips cutoff with less brake pressure