[wagonman76]

Im not sure about the Aveo, but the Fiero should be just like my cars. The VSS sends 4000 cycles per mile to the ECM (or VSS buffer), but not really in pulses. It is more like a sine wave because the VSS is basically an electromagnet. Not really friendly for the mpguino to use. The ECM or buffer turns this swinging signal into discrete square wave pulses at 4000 PPM to operate the speedometer and cruise control. My mpguino works rock solid.