I also have a 2015 HRV and I have the same CTBA problem. It first appeared at night when it was cool. I manage to change the settings on the dashboard and the CTBA message disappears for few hours and then comes back on. Sounds like a defect with our modelshow hot was it?
apparently the sensor is inside the rear view mirror.
"The Honda HR-V VTi-S and VTi-L were further equipped with:
- City-Brake Active System (CTBA): operating at speeds between 5 and 32 km/h, CTBA used a radar sensor located in the rear view mirror to monitor the road ahead. If a potential collision was identified, the driver would initially receive visual and audible warnings. If the driver failed to respond, autonomous braking would be applied to avoid or mitigate the severity of a collision"