The CKP sensor is used as an input for tachometer information. The CKP sensor sends the PCM module an A/C voltage signal. The PCM uses the A/C voltage signal from the the CKP sensor to calculate RPM. The PCM sends an averaged tachometer message to the I/P cluster over the Class II link every 100 ms. The PCM averages the tachometer information to ensure smooth tachometer fluctuations.