Tire pressure sensor code

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.

https://www.2carpros.com/articles/abs-wheel-speed-sensor-test

Hope this helps. Let me know how you make out.

Joe