Abstract: A number one cylinder ignition signal from an engine is utilized to initiate counting of low coil signals from the same engine, and coincidence of a count equal to the number of cylinders in the engine and a subsequent number one cylinder ignition signal causes generation of a valid one signal and shifting into a mode in which subsequent valid one signals are simply generated by the counting of low coil signals, whether or not coincident number one signals are present. Thus, pseudo number one signals are generated from low coil signals when in the run mode; the run mode will continue indefinitely unless the count overflows (as from a failure) or is re-initiated by external action.