curious, so I downloaded the owners manual
while it shows several pages of 'screens' there isn't a LIST of 'error codes' !!!
THAT is just 'painful' !!!!
Maybe ask google 'kxo40-4 syserr' ? or somthing similar ??
to me 'syserr' is a SYStem ERRor.. a major brain fault, not a silly little sensor problem.