Network, generic

U05BA Invalid Data Received From Rear Radar Module D

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

Rear radar module D is the fourth unit in the rear numbering and is reserved for layouts with an unusually dense sensor set at the back. Neither U05BA nor the matching lost-communication code U02B9 is described by any manufacturer in public, so there are no published thresholds or fitting positions. The code says that module D transmits, but the receiving assistance controller treats its frames as invalid, for instance due to a failed checksum or counter, an implausible status or a sensor that was never coded. Because radar functions such as parking help, exit warning and lane change support can draw on several rear sensors, a single faulty unit usually degrades only part of them. Mercedes-Benz shows for rear modules A and B that calibration rather than replacement is often the cure.

Likely causes

Rear radar D not coded to the vehicle
Assistance controller software rejects data from module D
Rear radar D internally defective

Symptoms

  • Individual rear warnings such as exit warning not available
  • Assistance message in the instrument cluster

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–1,500
Time0.5–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

rear radar module d

Related codes

U02B9U05B9U05B8

References: bosch-mobility.com, static.nhtsa.gov.