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DTC codes / U05xx · Network communication / U05BA

U05BAInvalid Data Received From Rear Radar Module D

U05BA means the vehicle's network received data from the rear radar module that failed the module's own validity check, so the message was rejected as corrupt or out of range. The computer detected a checksum, counter, or plausibility error in the radar module's broadcast rather than a complete loss of communication.

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

Symptoms you may notice

  • A warning light or message for blind spot monitoring, rear cross traffic alert, or rear collision warning
  • The rear radar features stop working or behave erratically
  • A chime or intermittent alert with no obstacle present
  • Often no symptoms besides the warning light
  • Other driver assistance features may be disabled as a precaution
  • The message may clear after a restart and return later

Common causes, most likely first

  1. Corroded, loose, or damaged rear radar module connector or pins
  2. Water intrusion into the rear radar module or its connector
  3. A failing rear radar module that broadcasts invalid data
  4. CAN bus wiring damage or poor splice in the rear harness
  5. Voltage supply or ground problem at the rear radar module
  6. Software or calibration fault in the rear radar module
  7. A faulty module on the same network corrupting shared data

How to diagnose and fix it

  1. Scan all modules and record every stored code before clearing anything
  2. Inspect the rear radar module connectors for corrosion, water, and loose pins
  3. Check battery voltage and the module's power and ground circuits under load
  4. Inspect the rear body harness and CAN wiring for chafing or poor splices
  5. Verify the rear radar module software is current and recalibrate if required
  6. Substitute a known-good rear radar module only after wiring and power checks pass
  7. Clear codes and road test to confirm the fault does not return

Why the rear radar data is rejected

  • A validity error is not the same as a no-communication code, so the module is still talking but its message content is being rejected.
  • Water ingress at the rear radar module is a frequent cause that looks like an intermittent module failure until the connector is opened.
  • Low voltage during cranking can make the module broadcast out-of-range data, so check the battery before condemning the radar.
  • A poor ground shared with rear lighting or parking sensors can corrupt the radar module's data without setting a separate ground code.
  • Aftermarket trailer wiring or rear bumper repairs often disturb the rear radar harness and create this exact validity fault.

Can I keep driving with U05BA?

The vehicle remains safe to drive because the rear radar features are disabled, but do not rely on blind spot monitoring or rear cross traffic alert until the fault is repaired. Avoid towing or rear bumper work that could further disturb the module wiring.

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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