CANBUS Communications Fault (U0100)

This fault is only enabled if the BMS is specifically configured to monitor for the presence of external CAN message, if used with an external module that requires 2-way communication such as a thermistor expansion module or if multiple BMS units are strung together in series (master-slave mode). This error is set if communication messages are not received after a specified amount of time. This error is most commonly caused if the BMS and the other device are powered up or down at slightly different times (not powered by the same power rail) or if the CANBUS is not properly terminated.

Resolving the issue:

Step 1) If the BMS is a part of a master-slave configuration or is connected to an expansion module requiring 2 way communication, ensure proper CANBUS configuration and ensure that other units are powered up and powered down at exactly the same time. Check the CAN connection for errors which may arise from electronic noise, improper shielding, improper CANBUS termination, non-twisted pair communication cable, ground loops or other wiring problems such as cut cables.

Step 2) If the BMS is not subject to 2 way settings in step 1 and is not intended to be setup to listen for heartbeat messages from other ECUs, ensure that no messages are setup as ?Receive? messages.

Step 3) If the BMS is listening for heartbeat messages from other ECUs, ensure the heartbeat messages the BMS is indicating that it did not receive the heartbeat messages.