The warning lamp lights up when the parking brake is applied.
Caution: Audi A4 parked too steepIf the warning lamp flashes and the message appears, the brake may not be strong enough to hold the Audi A4.
If the warning lamp flashes on its own, the brakes have overheated. The Audi A4 can roll away, even on a gentle slope.
Press brake pedal to release parking brakeTo release the parking brake, press the brake pedal and simultaneously press the switch 
(alternatively, use the auto release function Link).
(alternatively, use the auto release function Link).
Parking brake!There is a malfunction in the parking brake. Drive to a qualified workshop without delay and have the fault rectified.
Note
For further information on the parking brake refer to Link.