Check engine light Code 55

I ran a diagnostic on my 92 Toyota Camry and got code 27 (sub o2) and code 55 in the Haynes manual it says knock control signal (v6 engine RH bank), problem with knock control system in ECM, trouble are ECM. I would like to know how to fix this problem as it doesn't seem as if the knock control sensor need to be replace. thanks for any help in advance.