Automatic check failed

[BestRadarDetectors]

Hello, I found that the sensor which wrong, I've disconnected it and I let the 1 which is OK on R1 position. When the CPU starts, it says 'Automatic check failed: R2 F2'

When I connect only one sensor, the defective sensor to R1, I get this 'Error 2 defective sensor'

Is the CPU box is wrong as well?

You might have a bad cable and not a bad sensor. What you need to do is reconnect both sensors and see which sensor is online. Then take the other sensor the one showing an error (Disconnect it from the wiring connector at the sensor) and try that head on the working sides cable. If you just move the sensors from one port to the other you are still using the same cable.