I would assume a wheel speed sensor,
ABS - Cant identify if a wheel locks up
DBC - Cant identify when one wheel is braking more than the other.
Tyre Monitoring - Uses the wheels rotational speed to identify if it has a different diameter than the other wheels and thus lower pressure.
Start Assistance - Not sure if this is similar to the hill assist on the Manuals, But without being able to detect wheel speed when you apply the brakes it doesnt know whether the car is completely stationary.
'06 E90 325i 6MT | Full M3 Kit | H&R Euro Race | VMR V710 | Colour Kidneys
:: My Tutorials