Complaint Distronic and/or Active Brake Assist inoperative after driving for an extended period Cause...

Bulletin number

LI54.71-N-075673

Component

Electrical system

Summary

Complaint Distronic and/or Active Brake Assist inoperative after driving for an extended period Cause Blindness detection of the radar sensor. When driving for extended periods in areas with few or no objects for the radar sensor to detect, the radar sensor switches off due to the self-test and sets fault code C174AFB - The adjustment of the 'Active Brake Assist' control unit has malfunctioned. Remedy • Check the area of the front radar for damage. • Check whether fault code "C174AFB - The adjustment of the 'Active Brake Assist' control unit has malfunctioned" is set in the B92 or B92/1 Active Brake Assist/Active Distance Assist DISTRONIC (ABA/DTR) (FCW177) control unit. • If the fault code is present, check the vertical actual values. • If these are not OK, please correct the value with inspection of installation position or calibration of installation height (see attachment 2021 NDTD_Vans_Radar Sensor for best practices and functionality info) • If the actual values are OK, please update the software.

Owners of these vehicles have filed 72 complaints in the electrical category.