BAS ESP warning light on 2002 ML270 CDi

[johngoth]

This warning light has come on and stays on.
Reading other posts decided to change brake light switch as this often seems to be a cause of this. A new switch has been ordered.
Removed cover under dash near brake pedal to access switch to discover that there is NO switch there.Bracket is there for a switch but it is empty. Also no wiring connections.
Stop/Brake lights come on when you press the brake pedal - how can this be without a switch?
Can anyone advise me?

 

[johnsco]

The warning light may be caused by a failed abs sensor or a failure of the reluctor ring that the abs sensor senses.
The most-likely one is just inboard from the back of the brake plate on one of the back wheels