Why does my car say front radar blocked when nothing is in front of it?
Short answer: Common causes are dirt, ice, snow or bugs on the radar cover, a misaligned or damaged sensor, an aftermarket grille or plate bracket, or water inside the sensor; scan the module before replacing anything.
The radar compares the strength of returning signals with what it expects. Anything that absorbs or scatters the signal, such as slush, a thick layer of road grime or a heavy coat of wax on the emblem, can trigger a blocked message. These messages often clear once the cover is cleaned and the vehicle is driven.
When the message persists in clean, dry conditions, look for physical causes: a cracked emblem or radar cover, a license plate bracket or bull bar in front of the sensor, or a bent bracket from a minor impact. Check service information for any related technical service bulletins as well.
Read codes and live data from the radar module with a capable scan tool. Some modules report misalignment angle or signal quality, which helps separate a blockage from an aiming problem. Perform an aiming check or calibration if the data or the maker's procedure calls for it.
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General guidance only. Follow the vehicle and tool manufacturer's procedures, and confirm vehicle coverage on the tool maker's list before buying.