Timing Change?

[gtolds]

02 ls 400

When a normal car's knock sensor detects engine knock, it retards timing. The question I have is if the ECU faults one of the two knock sensors (code 55 in my case), will the ECU not !Removed! the timing, default to the retarded timing or only !Removed! the timing if the knock happens on the remaining good sensor?

Thanks and I know this is a hard question so thanks if anyone can figure this out.