Reference Waveforms and Diagnosis

There are times when a Reference waveform can be used for diagnosis and times that it has little value.

Ideal for...

Reference waveforms are ideal for repetitive signals that do not change much in shape. For example, an ignition primary or secondary signal. Ignition signals should maintain shape and consistency throughout the RPM range. Other possibilities are injector at idle or a wheel speed sensor at a fixed speed.

Not Ideal for...

They are not ideal for signals that dynamics change such as a wheel speed sensor while on a road test. Or a analog mass air flow sensor.