Compared with ICOM A+B+C, BMW ICOM A2+B+C has the some special features. The modified ICOM A2 for vehicles with OBD access receives a significantly more powerful processor and more storage capacity. Robust aluminium case will help to avoid damage when using in harsh environments.
To protect the MOST connector, the ICOM B for vehicles with optical MOST access will be equipped with a soft cover made of rubber instead of the former plastic cap. The ICOM C for old series with a diagnostics socket will be additionally equipped with an approx. 20 cm long cable, which facilitates the connection of the BMW ICOM A2 and makes storage in the engine compartment easier.
If your BMW ICOM firmware works normally, then DO NOT need to update. If your firmware is not compatible with your software very much, then need to update the firmware. Because every new version ICOM software will change a little. Firmware need update so that can fit the latest ICOM software perfectly.