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U05B8 Invalid Data Received From Rear Radar Module B

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

Module B is the right-hand rear corner radar in the only public manufacturer use: Mercedes-Benz lists U05B855 for the outer right rear sensor of the 2026 CLA electric. The fault type 55 reads as not configured, so the content is rejected because the controller N62/5 has no valid setup for that sensor, not because the radar is broken. The May 2026 version of bulletin LI54.71-P-080345 narrows the case to cars built before 27 February 2026 with persistent warnings and drops the hardware reset step of version 1; afterwards the car must sleep for seven minutes, and full assistance returns after roughly ten more minutes of driving. Replacing the sensor is therefore rarely the first step. Right-side blind spot and cross traffic warnings fail. U02B7 means module B is silent.

Likely causes

Right rear radar not configured, calibration of the assistance controller missing
Initial calibration of the controller's acceleration sensor not completed
Right rear radar internally defective

Symptoms

  • Blind spot indicator on the right stays off
  • Assistance warnings reappear on every start
  • Rear cross traffic alert missing on the right

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 b

Related codes

U02B7U05B7U05BAU0534

References: static.nhtsa.gov, static.nhtsa.gov, en.wikipedia.org.