ESP/BAS & ABS warning lights in A-140

[johnmanoj1]

Hi guys,
I really need some help here.I recently pruchased a 2nd hand A-140 Elegance auto.I noticed that the ESP/BAS and ABS warning lights come on and stays on till I switch the ignition off.this happens only while I am driving on motorways and i have noticed that it doesnt come on if i am driving on city roads.i took it to a garage and they came up with 2 possible faults---the steering wheel angle sensor and brake light switch.they initialised the sensor and the next day again the lights came on.this time they changed the brake light switch and cleared all fault codes.but unfortunately while driving to work on the motorway the lights came on again.i have not accelerated or braked harshly.it just comes on even if i am on a constant speed.I must also say that out of 5 times that i drove on the motorway since the last repair it has occured thrice.I am really frustrated by now.
Can anyone suggest anything?Any advice or tips to check where the fault is?
I would like to add that while i had given it for service A,the mechanic had put a note saying "Whining noise from bottom pulley,needs investigation".Has this got something to do with the warning lights?Please somebody help me.

Thanks,
Manoj John

[JOE55]

Welcome to the Board Manoj John,

Sorry to hear about your problem regarding your warning lights, have your battery check.

Take care & enjoy the ride,
Joseph

[MUSTANGMAN]

WHEN THAT LIGHT COMES ON IT COULD BE A MASSIVE NUMBER OF THINGS AS IT COVERS ALL 3 SYSTEMS......A BIG MISTAKE BY MERCEDES IN MY OPINION!
THEY WOULD HAVE BEEN BETTER USING BRAKE AND ESP LIGHTS SEPERATELY ?
DONT WASTE YOUR TIME TRYING TO SOLVE IT YOURSELF.....YOU WILL SPEND A FORTUNE REPLACING PARTS BEFORE YOU HIT THE PROBLEM ONE.
GET IT BOOKED IN AT MERC DEALER FOR A DIAGNOSTIC CHECK FOR £50 .....DONT USE SNAP ON OR OTHER SYSTEM CHECKERS.........MERCEDES HAVE US BY THE GOOLIES ON THE DIAGNOSTICS ......SORRY !

[JOE55]

The battery voltage was dropping down under 10 volts at times which is the threshold for the ESP/BAS system according to the Owners Manual.