DTC P0604: Control Module Random Access Memory: Description
Powertrain Control Module (PCM) copies program information that is stored in the Electrically Erasable Programmable Read Only Memory (EEPROM) to the Random Access Memory (RAM). This allows PCM to work with, and update the information. PCM tests all areas of the RAM. If PCM detects an error in any area of the RAM, DTC P0604 will set.