U05B5 code meaning
Invalid Data Received From Front Radar Module A
What U05B5 means
Front radar modules measure distance and closing speed of objects ahead for adaptive cruise, emergency braking and lane change support. Mercedes-Benz documents this code on the 2026 CLA electric (series 174): the driver assistance controller N62/5 stores U05B555 when the front radar on the outer left delivers implausible data because it has not been configured. Bulletin LI54.71-P-080345 (versions of April and May 2026) ties it to a lasting warning that the assistance systems are unavailable, mainly on cars built before 5 September 2025, and calls for an N62/5 teach-in calibration or a calibration drive followed by at least seven minutes parked and locked. Other brands use letters differently, so A is not always a corner sensor. U02B4 means module A is silent; U05B6 is the right twin.
U05B5 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyHard
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U05B5
- Driver assistance unavailable message that does not clear
- Adaptive cruise and emergency braking switched off
- Lane change or blind spot functions on the front left limited
Common causes of U05B5
- Most likelyRadar sensor not configured or calibrated in the assistance controller (Mercedes N62/5)
- PossibleOutdated software in the driver assistance controller
- PossibleRadar knocked out of alignment after bumper damage or repair
- Less likelyRadar connector behind the bumper loose or wet
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Front radar module a
What each part of U05B5 means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| B5 | The exact fault in that area. |
What to do next
- Note U05B5 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about U05B5
What does U05B5 mean?
U05B5 means "Invalid Data Received From Front Radar Module A". Front radar modules measure distance and closing speed of objects ahead for adaptive cruise, emergency braking and lane change support. It is a generic code, so it means the same on every make.
Is it safe to drive with U05B5?
U05B5 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will U05B5 fail an emissions test?
U05B5 is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is U05B5 to fix?
Difficulty: hard. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will U05B5 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.