BYD ADAS system fault: FCW, AEB, BSD and lane-assist warning messages
What it means when BYD's driver-assistance systems (FCW, AEB, BSD, ICC/LKA) show a fault prompt, and what stays your responsibility as the driver.
Safety and service note
What this means
BYD's instrument cluster can show individual fault prompts for its driver-assistance features: "Please check the FCW system" (forward collision warning), "The AEB function is limited" (automatic emergency braking), "Please check the BSD system" or "BSD limited" (blind spot detection), and "Please check the ICC or LKA" or a limited-function message for intelligent cruise control and lane keeping assist. According to the official handbook, each of these means the specific system is faulty or its function is limited -- the assistance feature named should not be relied on until the fault clears.
What causes it
These systems rely on cameras and radar sensors that can be temporarily affected by a dirty or obstructed sensor, heavy rain, fog or snow covering a camera/radar area, or a genuine electronic fault. The handbook's response for every one of these prompts is the same: park the vehicle safely and contact a BYD authorised dealer or service provider.
What to do
If a sensor is visibly dirty or obstructed (for example by mud, snow, or a sticker placed over a camera or radar area), cleaning it and restarting the vehicle can resolve a temporary block. If the message persists after that, or there is no obvious obstruction, park safely and contact a BYD authorised dealer or service provider -- do not rely on the affected driver-assistance feature until it is confirmed working again, and always keep full manual attention to the road regardless of ADAS status.
Important
If a sensor is visibly dirty or obstructed (for example by mud, snow, or a sticker placed over a camera or radar area), cleaning it and restarting the vehicle can resolve a temporary block. If the message persists after that, or there is no obvious obstruction, park safely and contact a BYD authorised dealer or service provider -- do not rely on the affected driver-assistance feature until it is confirmed working again, and always keep full manual attention to the road regardless of ADAS status.
Frequently asked questions
What does "Please check the FCW system" mean?
The forward collision warning system is faulty; per the handbook, park the vehicle safely and contact a BYD authorised dealer or service provider.
What does "The AEB function is limited" mean?
The automatic emergency braking system's function is limited or faulty; the same handbook guidance applies -- park safely and contact BYD service.
What does "Please check the BSD system" or "BSD limited" mean?
The blind spot detection system for lane changes is faulty or its function is limited; treat it the same way -- park safely and contact service.
Can a dirty camera or sensor cause these messages?
Yes, a dirty or obstructed camera or radar sensor is a common, fixable cause; clean the sensor area and restart the vehicle before assuming a deeper fault.
Should I still watch the road myself if ADAS is working normally?
Yes -- these are driver-assistance features, not a replacement for the driver's own attention, whether or not a fault message is showing.
Does this apply to BYD models across the range, not just one?
Yes -- FCW, AEB, BSD and ICC/LKA fault prompts and their handbook guidance are described the same way across BYD's current EV and DM-i models that include these features.
Sources for this guide
This guide is for informational purposes only. Always consult an authorised service centre for safety-critical repairs. AutoTechHelp is not liable for any damage resulting from the use of this information.