I have a 2 car bank and every few months car one will get a bunch of intermittent problems with I/O mismatch faults and can faults and checksum faults parameter faults etc… I reload the files form the usb using the uit and car takes off runs fine for months then it happens again. Just wondering if anyone has any ideas what would cause it I’ve replaced the battery on the cpua last time I was here before reloading the usb but other than that idea it’s kind of baffling me. Thanks in advance.

Next time it happens I’d see what it takes to get it running without reloading the job. If it has NV RAM errors try a GET command. That will also tell you if any parameters are out of range. One thing that could be happening is J16 could be changing on you. Should be 18 on a TAC32. Usually changes to 0 but I’ve seen it change to 17. Check your power supply for ripple and the controller grounding. If you are getting repeated NV RAM errors or a parameter keeps changing on you, all you can really do is replace the CPUA.