The ESP and BAS warning lights may illuminate due to a failed brake light switch. Replacement of the failed switch should correct this concern.Google+
Car Problem Reports
Mercedes-Benz E320 4MATIC Brake Light Switch Failure May Cause ESP/BAS Warning Lights
Mercedes-Benz E320 4MATIC Problem
Average Mileage: 99,250 mi (43,000 mi - 150,000 mi)
Red light comes on states Stop Reducing Break Power and my vehicle brakes barely works or stops the vehicle, The Warning is in Red and also the ESP Malfunction comes on ...Not very safe when this happens just had brakes and sensors done so they are fine
Visitor, 2005 Mercedes-Benz E320 4MATIC, 128,500 mi
RED brake light warning/Brake Malfunction message as follows: Reduce Braking Power - Depress Brake Fully. Loud beeping noise accompanied warning.
Brakes seemed to work fine after light went on.
Visitor, 2001 Mercedes-Benz E320 4MATIC, 43,000 mi
Suddenly ABS,BAS, and ESP warning lights came on. That's car drove well before and after the lights came on. I took it to my mechanic who diagnosed a broken brake switch, he replaced it, all three lights went off, and the car still drives great.
Visitor, 2000 Mercedes-Benz E320 4MATIC
Replaced the BLS and did the steering wheel left right thing all the lights went out but the BAS light then they all came back on yesterday back to the diag board
Visitor, 2000 Mercedes-Benz E320 4MATIC, 150,000 mi
had to replace the switch several times, aftermarket switches were bad 2 times.
Visitor, 1999 Mercedes-Benz E320 4MATIC, 92,000 mi
ABS ESP BAS warning lights on after starting when brake pedal is lifted. Not yet fixed.