The ESP and BAS warning lights may illuminate due to a failed brake light switch. Replacement of the failed switch should correct this concern.
Car Problem Reports
Mercedes-Benz ML350 Brake Light Switch Failure May Cause ESP/BAS Warning Lights
Mercedes-Benz ML350 Problem
Average Mileage: 167,582 mi (100,000 mi - 235,165 mi)
Visitor, 2003 Mercedes-Benz ML350, 100,000 mi
Constant beeping when vehicle is in motion. Brake and ESP lights on dash illuminated.