Dear customer already at this point, given the error codes I would be concerned with a failure in the ECU of your Chrysler, I explain:
It is true that there are many causes of this type of failure can be even from the injection pump, but what surprises me are the precise error codes that you have, just these error codes are clearly referring the injectors and have already been replaced and tested voltages and pulses in the wiring looms, it seems that the computer can not encode the return signal for some reason.
I am going to recommend you dear customer to check the injection pump by taking it to a technician who can see if it is distributing the fuel correctly with the same pressure to the 4 injectors and that it is not obstructed by dirt, only to rule out that the problem is not is concentrated here and that by a pressure drop the injectors can not work properly and the computer can not correctly encode the signal.
But if once this is done, the problem continues, i will recommend you to consider to locate a test ECU, you can locate a garage where they have other Chrysler to which they are doing work and can proceed to replace the ECU to see if the problem is corrected , you can also go to a scrap yard where they have another equal voyager and tell them to please let you check if there are problems in the ECU so that you can immediately buy it. Given the problem presents, i canencapsulate your query to these answers.
Of course, I would also like you to please check the compression of the cylinders to see that it is not a low compression in the cylinders and the injectors are not getting a good signal for this reason.
Have you understood dear customer?