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DTC codes / U05xx · Network communication / U05B6

U05B6Invalid Data Received From Front Radar Module B

U05B6 means the vehicle's main computer network has received data from the front radar module B that it considers invalid or corrupted, so it cannot trust the sensor's readings. The radar module is used for driver-assistance features like adaptive cruise control and automatic emergency braking, and the fault is set when the data fails plausibility or format checks.

SystemNetwork
Code typeGeneric (all makes)
SeverityMedium
Fix difficultyIntermediate
AreaNetwork communication

Symptoms you may notice

  • A warning light for the forward collision or adaptive cruise control system, often with a message to service the system
  • Adaptive cruise control or automatic emergency braking becomes unavailable or disengages unexpectedly
  • A chime or intermittent alert that the front radar sensor is blocked or unavailable
  • Often no symptoms besides the warning light, with normal driving behaviour otherwise
  • The vehicle may default to conventional cruise control if adaptive cruise is disabled

Common causes, most likely first

  1. Corrosion or water intrusion at the front radar module connector or pins
  2. A failing front radar module B that intermittently outputs corrupted data
  3. Damaged or chafed wiring in the harness between the radar module and the network gateway
  4. A software or calibration issue in the radar module after a battery replacement or collision repair
  5. A network communication fault, such as a CAN bus error, that corrupts the radar data in transit
  6. A misaligned or obstructed radar sensor causing implausible data that the computer rejects

How to diagnose and fix it

  1. Inspect the front radar module B connector and pins for corrosion, water intrusion, or loose terminals, and clean or repair as needed
  2. Check the radar sensor face and mounting bracket for damage, debris, or misalignment that could produce invalid data
  3. Scan all modules for related communication codes and freeze-frame data to see whether the fault is intermittent or continuous
  4. Perform a wiggle test on the radar harness while watching live data to catch an intermittent wiring fault
  5. Verify the radar module has the latest software and recalibrate it according to the manufacturer's procedure if required
  6. If data remains invalid after wiring and software checks, replace the front radar module B and perform calibration
  7. Clear codes and road-test the vehicle to confirm the fault does not return

Before you replace the front radar module

  • A weak or failing battery can cause the radar module to boot incorrectly and send invalid data, so always load-test the battery before condemning the sensor.
  • Water intrusion into the front bumper area is a common hidden cause, especially after a car wash or heavy rain, and the connector often looks fine until it is unplugged.
  • This code can be set by a network gateway or CAN bus fault rather than the radar itself, so check for other U-codes that point to a shared communication problem.
  • After any front-end repair or bumper removal, the radar must be recalibrated; an uncalibrated module can send data the computer rejects as invalid.
  • Do not assume the radar is defective just because the code names it; the invalid data may originate from a poor ground or voltage drop on the module's power circuit.

Can I keep driving with U05B6?

The vehicle remains safe to drive because the fault disables only driver-assistance features, but you should not rely on adaptive cruise control or automatic emergency braking until it is repaired. Avoid long trips where those systems are expected to work, and have the fault diagnosed soon to prevent further network issues.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

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