rccmerc

When you start the car and put it in reverse to back out of say a parking space and then put the car in drive and begin to move forward 10 - 30ft. the car makes a buzzing sound for a few seconds. It only makes this noise when the car is off and then you start it. You can replicate the noise by parking the car and turning the car off, take key out of ignition. Wait for a minute, then start the car put it in reverse and then put it in drive and in the first few feet of driving forward you will hear the “buzz”.

The Dealer tells me it is normal - that it is a K Bit Test for the Anti-Lock Brake System - Self Test.

Another interesting thing is this noise started after I had the dealer do a brake flush, but again they say noise is normal.

Any insight would be most appreciated.

tunayballa

My mechanic told me it's just stuck...the abs assembly. He told me it doesn't do any damage to anything. Sure enough it went away and hasn't come back. That was for my 190e though. I assume it's the same problem for your car.

rccmerc

Is it possible that when the dealer did the brake fluid flush, they did not cycle the ABS solenoids and now there not seating correctly, thus causing the buzzing sound?