Tachometer

The CKP sensor is used as an input for tachometer information. The CKP sensor sends the EI module an A/C voltage signal, which it converts to a Pulse Width Modulated (PWM) 0 to 5 volt square wave received by the PCM. The PCM uses the PWM square wave from the EI module 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.