Since your getting the 604E, I would check the wiring and connectors at the RDC unit. Could be loose, corroded, or bent pins. If they are good, then replace the sensor.
Here is a link that shows how to test the sensor itself using a multi meter. You may want to consider doing this to see if the sensor itself is the issue.
Hope this helps. Let me know how you make out.
Monday, March 23rd, 2020 AT 12:56 PM