312000163 - F033 ANTI-SLIP FUNCTION NOT WORKING - ASR AND MSR

When the ASR is engaged the message "ASR on" does not appear on the display for 5 seconds; the LED in the button remains on (indicating that it is switched off).
Test results
1CHECK USING DIAGNOSTIC EQUIPMENTAll OKProblems encounteredOperation
Connect the Examiner Plus or Smart diagnostic equipment to the diagnostic connector and check the following at the brake node:- in the errors ambient, that there are no faults;- in the parameters ambient, the plausibility of all the parametersMove on to Step 21. Error detected in the control unit2. No communication with the control unit.1. Continue following the instructions for the diagnostic equipment 2. Restore the connection between the ABS control unit and the diagnostic connector see    See E7020 ABS
2SWITCH CHECKAll OKProblems encounteredOperation
Check the operation of the ASR switch checking that there is a short circuit with the button pressed and an open circuit with the button released    See E7023 ESP Move on to Step 3Switch defectiveReplace the switch
3CHECKAll OKProblems encounteredOperation
Check the continuity/insulation of the ASR switch connections    See E7023 ESP End of diagnosisNo continuity/insulationRestore the correct connections    See E7023 ESP