Often the drivers of BMW 3 E90 can't only understand what the error is, and it is in such cases that a simple and efficient way of reading the error code will be useful:
1. First of all, the "CHECK" function must be called using the two-position key.
2. Next, press the "BC" key.
3. Use the 2-position key to display all messages, down to the error message.
4. Press and hold the "BC" key until the message displays in the form CC-IDxxx at the bottom of the display (instead of "x" the digits appear). This message will be the error code.