XC42 blink code R4:3 3:1:6

In brief, it is from a diagnostic function on the IC that manage voltages on the module. With existing software versions, I know two situations that could trigger the diagnostic function that give this blink: 

One is if you have a VREF error such as an overload that is not taken care of, if you are unlucky this could come when the module tries to reactivate the VREF. 

Another case is if module supply voltage drops down below 6V, but not low enough to restart the module. (this under-voltage could cause different symptoms too)

My suggestion is to cycle power to the system and the XC4 will recover. 

Our customer has found a damaged cable in one of the sensors connected to the Vref.

The cable has been changed, hopefully this will fix the blinking code appearing intermittently.

Thanks for your clues!