DTC P0601 - Internal Control Module Memory Check Sum Error, DTC P0603 - Internal Control Module Keep Alive Memory Error
WARNING: This page is about a different car, the 1996 Suzuki Swift. However, it is still accessible from the selected car via links, so may be relevant.
Connect scan tool to Data Link Connector (DLC). Clear DTCs. Turn ignition off. Start engine if possible. If DTC P0601 or P0603 resets, replace PCM. Retest system.