P0605-Internal Control Module ROM: 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 the program memory (ROM). A checksum is calculated by adding all used bytes in the program memory. The sum should be the same as a known constant stored in the program memory  .

• 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.   .