if you've changed ion to hpo you will have to change programming in consys or you will get id faults, also any faulty device on the loop can cause low and high id faults on other devices, a faulty mcp causing id faults is common only way to prove is to discon one device at a time and link the loop thru and check the levels unless you have a shorting device which speeds up the process its a pain of a fault to trace