BYD | BCU LED Event Codes (EC) | 203–803

A continuously white LED indicates standby. A flashing white LED indicates charging or discharging. When the battery starts, the LED flashes white and blue at 0.5-second intervals, normally for about one minute during startup. If the LED flashes blue at 1-second intervals, it is displaying an event code. Start counting when the white LED begins to flash, then count the blue flashes.
Examples:
1x white, 3x blue → EC 103
1x white, 11x blue → EC 111
3x white, 3x blue → EC 303
Many faults are caused by an incorrect communication connection, incorrect app configuration or a missing restart after configuration with the app or BCP tool.

EC 203 | EC 303 | EC 403 | EC 503 | EC 603 | EC 703 | EC 803
Incorrect number of modules / module not detected.

• Make sure the app configuration has been completed correctly, especially the number of modules and the module type (HVS/HVM).
• EC 203 through EC 803 indicate that a module is not being detected. The first digit, represented by the number of white flashes, indicates the affected module position. The affected module or the module directly above it can be responsible. Example: EC 103 refers to the top module; EC 403 refers to the fourth module from the top.
• Remove the affected module and check whether the event code disappears. If not, check the module above it.
• Rearrange the modules in the tower and test again.

Note: A module with a communication problem can sometimes operate without restriction in the lowest module position because no communication to the base is required from that position.