Powertrain Control Module: Introduction
WARNING: This page is about a different car, the 2002 Buick Regal, 2002 Buick Century, 2001 Buick Regal, and 2001 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.
Service of the PCM should normally consist of either replacement of the PCM or Electrically Erasable Programmable Read Only Memory (EEPROM) programming. If the diagnostic procedures call for PCM replacement, check the PCM first to see if the replacement PCM is the correct part. If the PCM is faulty, remove the PCM and install the new service PCM.
The new service PCM will not be programmed. You must program the new PCM. DTC P0602 indicates the EEPROM is not programmed or has malfunctioned.