E430 ESP/BAS problem

[vince]

1999 E430. The "ESP" warning came on in the Malfunction Indicator while traveling a straight section of highway at 60 mph. The "multiple malfunction" indicator (looks like two pages super-imposed on each other) came on also. The "ESP Warning Triangle" in the speedometer did not illuminate. The ESP switch on the console did not work. When I shut the key off (for a gas stop) the "BAS" warning came on in the Malfunction Indicator. When I restarted the car both had cleared. In the recent past the "ESP Warning Triangle" in the speedometer dial had come on briefly when making turns at moderate speeds (25-35 mph) in normal, not aggressive driving, on dry surfaces. Also, the "ESP Warning Triangle" in the speedometer dial had come on, and what sounded like the ABS system activated, during a turn in a cul-de-sac under the same seemingly ideal conditions. It seems as if the threshold for ESP intervention has somehow become too low. My dealer says the brake booster is at fault. Does this seem logical? I do not have any codes yet.