DTC P0603: Control Module Long Term Memory Reset: 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 P0603 will set.