U02B8 Lost Communication With Rear Radar Module C

A third rear radar is only fitted where the usual left and right corner pair is extended, for instance by a sensor watching straight back or along a long body. No manufacturer documents U02B8 publicly or states where module C sits, and its invalid-data partner U05B9 is equally unpublished. The documented rear letters belong to the corner pair: Mercedes-Benz gives A to the left and B to the right outer sensor at the back of its 2026 CLA electric. U02B8 means module C has dropped off the bus, so functions that rely on its field of view, typically cross traffic or exit warnings, lose part of their coverage while the corner units may keep working. Check its connector and supply first, then the module; after replacement the radar usually needs calibration.

Likely causes

Symptoms

• Rear assistance functions partly unavailable, assistance message
• Cross traffic or exit warning restricted

Repair estimate

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

Parts involved

Related codes

References: bosch-mobility.com, static.nhtsa.gov, en.wikipedia.org.