P0604-Internal Control Module Ram: Notes

For a complete wiring diagram  , refer to appropriate SYSTEM WIRING DIAGRAMS article.

After the controller is reset (ignition turned to the RUN position), the microprocessor checks the integrity of each RAM location by writing to it and reading back from it. The read value should be same as value written. 

• When Monitored: 

  One time after the controller is reset (ignition turned to the RUN position). 

• Set Condition: 

  Whenever the Powertrain Control Module (PCM) detects an internal controller problem. 

Always perform the PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE before proceeding.