DTC C1A67 4B: Radar Sensor Is Outside Of Operation Range (Ignition Power Supply, Internal Temperature): Notes

WARNING: This page is about a different car, the 2014 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

DTC C1A67:4B (VEHICLE CONTROL MODULE) DETECTION CONDITION AND POSSIBLE CAUSE

System malfunction location	Radar sensor is outside of operation range (ignition power supply, internal temperature)
Detection condition	Radar sensor power supply voltage is other than 9.5-15.5 V. Temperature in radar sensor exceeds specification.
Fail-safe	Inhibits the Mazda radar cruise control (MRCC) system control Inhibits the forward obstruction warning (FOW) system control
Possible cause	Generator system malfunction C/U IG1 15 A fuse malfunction Battery malfunction Open circuit or short to ground in wiring harness between battery positive terminal and radar sensor Radar sensor malfunction Vehicle control module (V/C-module) malfunction
Courtesy of MAZDA MOTORS CORP.