Hello in relation to the Caravan I am almost certain that the problem you have with the CKP, because the strategy of Jeep Chrysler Dodge, etc Coils and much less will activate the pump, quickly see if the computer is seeing crankshaft turn is to start and in the data flow of the scan see if there is RPM. The following if there is no RPM is to go to the rotation sensor and measure the signal with an oscilloscope to see what is seen. In these cars they work normally with 8 or 5V depending on the model. In relation to the Frontier, that fault is very rare let the manual check the weekend and warn you, for now check connectors and cables because you had initially told me that there was an injection pulse but it does not spark, and if there is a pulse it is because the computer is seeing crankshaft turn. I am attentive to your comments greetings.