BMS error – No Cell Communication

This error indicates that no communication can take place between the BMS main controller and the battery cells. This communication can be done via Cell Modules (circuit boards on the battery cells), a Tesla PCB module or Centralized Can Group modules to which up to 16 cell measurements can be connected.

    • Is the battery configuration completed in the EMUS bms system? if not completed see manual and/or watch our instructional video 5. When doing so, do not forget to press the “commit configuration” button as well, try this several times if necessary.
    • Check the resistance of the CAN bus. A 120 ohm terminating resistor should be placed at both ends of the CAN bus. Because of this, the total resistance measured should be 60 ohms if measured between CANL and CANH with the entire system (including the 12V power supply) turned off. If about 120 ohms is measured a 2nd resistor should be added, if about 40 ohms is measured a resistor should be removed/disconnected.
    • When using
      Centralized CAN group modules
      : Flashes the green LED on the ccgm module -> if not check the CAN connector.

      • Is the voltage between the red and black wires 12 volts?
      • Is the resistance between the green and white wire about 60 ohms (measured with no voltage on the system)?
      • Is the white wire connected to CANL and the green wire connected to CANH?
    • When using Cell modules, check that they are flashing green. Start this check at the HV negative side of the battery pack, this should also be the DN side of the communication between the cell modules. If the flashing stops at a particular module, check:
      1. Is the voltage of the battery cell more than 2 volts?
      2. Are the single wire communication wires connected properly?
      3. Is the communication sequence connected correctly. The communication is from the HV- to the HV+ of the total battery, that is, from DN to UP
      4. Swap out the board that is not flashing, or possibly the last module that is still flashing
    • When using Tesla print modules, check that they are flashing green. Start this check at the HV negative side of the battery pack, this should also be the DN side of the communication between the cell modules. On each Tesla cell board, 6 green LEDs should flash. If the flashing stops at a particular module, check:
      1. Is the voltage of each individual battery cell in the teslam module more than 2 volts? (A total of 6 cell blocks are present in a Tesla battery)
      2. Are the single wire communication wires connected properly?
      3. Is the communication sequence connected correctly. The communication is from the HV- to the HV+ of the total battery, that is, from DN to UP
      4. Is there possible damage to the original Tesla battery wiring?
      5. Swap out the board that is not flashing, or possibly the last module that is still flashing.
    • Is the Buzzer output in the BMS configured as PF12? To do this, open the BMS control panel and then go to configuration – I/O Pins –> BUZZER –> PF12 battery contactor

Also watch our video for instuctions: