The largest online repair guide library for every car

About us
Contact support
FAQ
Sign up
Sign in

2022 CX-30 BSM/RCTA System Malfunction Warning

0

Chris P. · rep 0 · May 22, 4:50 AM · 1 replies · solved · Question

Vehicle: 2022 Mazda CX-30 Premium

I'm getting a persistent "Blind Spot Monitoring System Malfunction" and "Rear Cross Traffic Alert System Malfunction" warning on my 2022 Mazda CX-30 Premium. Both systems are completely unavailable, and the warning lights stay on the dash. This started after a particularly heavy rainstorm we had last week.

I've checked the exterior sensors, which I believe are in the rear bumper, for any visible dirt or obstructions, but they look clean. I've also tried restarting the car multiple times. Is there a common fix for this, or could the rain have caused some electrical damage? I'm concerned about driving without these safety features.

✓ Accepted solution

ClearTheCode Admin

ClearTheCode Team · rep 0 · May 22, 4:50 AM

0

ClearTheCode admin answer:

Blind Spot Monitoring (BSM) and Rear Cross Traffic Alert (RCTA) systems rely on radar sensors, typically located behind the rear bumper fascia. A malfunction warning, especially after heavy rain, suggests a few potential electrical issues:

  1. Temporary Obstruction/Moisture: Even if the sensors look clean, heavy rain can sometimes cause temporary interference or moisture ingress that affects sensor performance. Allow the vehicle to dry thoroughly in a garage or sunny spot for a day or two and see if the warning clears.
  2. Sensor Contamination: While you've checked, sometimes a thin film of dirt, mud, or even ice can be hard to spot but still interfere with the radar signal. Ensure the bumper areas covering the sensors are meticulously clean.
  3. Wiring Damage/Corrosion: Water intrusion can sometimes lead to corrosion or damage in the wiring harness connecting the sensors to the main control module. This is more likely if the issue persists after drying.
  4. Sensor Malfunction: The sensor unit itself could have been damaged by water or simply failed. These are sensitive electronic components.
  5. Module Communication Error: The BSM/RCTA system communicates with other vehicle modules. A glitch in this communication can trigger the warning.

OBD-II Scan: A diagnostic scan tool will likely reveal specific codes related to the BSM/RCTA system. Common codes include:

  • B11D8: BSM Sensor Malfunction (Left or Right)
  • B11D9: RCTA Sensor Malfunction (Left or Right)
  • Other B-codes (Body codes) related to sensor communication or power supply.

When to See a Shop: If the warning persists after ensuring the sensors are clean and dry, it's crucial to take your CX-30 to a Mazda dealership or a specialist shop. They have the necessary diagnostic tools to read the specific B-codes, pinpoint which sensor or wiring segment is at fault, and perform any required repairs or sensor calibrations. Driving without these safety features can increase accident risk, so prompt attention is advised.

Menu

Help & account