i have the same damn problem. the knock gauge will flash to RED and the scan master will show 1.5 or 0 degrees.
direct scan said i had 4 *'s of KR, im guessing that 4 *'s is in between the scan master frames, and it only catches the begining or end of it before it retards the timing.
but i understand that it should not be flashing red with only 4 degrees. these gauges are screwy.