It's my understanding that the scanner (I also have one) is telling you the rev limiter at this time is off. If it were on it would be reducing your timing. You should be able to display how many times the engine has reached the rev limit (if it has ever)
The rev limiter is pre programmed into the ECM. You're just reading that it's not active/on at the moment, should you rev the engine past the RPM limit, the scanner would then read RPM limit on and go back to off once your back below the limit.
