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 E430 4MATIC Brake Light Switch Failure May Cause ESP/BAS Warning Lights
Mercedes-Benz E430 4MATIC Problem
Average Mileage: 110,333 mi (86,000 mi - 135,000 mi)
BAS/ESP warning illuminates when brake is depressed. Can cause brake lights to be inop or work incorrectly
Visitor, 2002 Mercedes-Benz E430 4MATIC, 86,000 mi
My brake lamp switch has failed 3 times in the last 5 years. The upper brake light comes on but will not turn off.
Visitor, 2001 Mercedes-Benz E430 4MATIC, 110,000 mi
About once a year I have to replace this part. Very frustrating... Cruise control stops working and brake lights are always on.