Ive got a KONE acting up with a 048 fault. I got here by trying to toubleshoot RIFF board (phone not working) by swapping it out with adjacent car. After swapping board, elevator goes to nearest floor and holds door open (fault 48). I thought i may have messed up the cable between RIFF and MUL but have tested and seems okay, which is leading me to believe the MUL is bad?

If MUL replacement is needed, do i have to reprogram the COP?

Thanks!