Crank Request

The crank request circuit is used to signal the PCM that the ignition switch is in the START position. With the ignition switch in the OFF position, the PCM should detect zero volts on the crank request circuit. With the ignition switch in the START position, the crank request circuit applies a fused ignition voltage to the PCM. The PCM uses the crank request signal, and other inputs to decide whether, or not to allow starter operation.