DTC P0603: ECM/PCM Internal Circuit Malfunction (Keep Alive Memory (KAM) Error)

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Turn the ignition switch ON (II).
Clear the DTC with the HDS.
Check for Temporary DTCs or DTCs with the HDS.
Are any Temporary DTCs or DTCs indicated?
1. YES- Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM (see ECM/PCM UPDATING AND SUBSTITUTION FOR TESTING ), then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM (see MAP SENSOR REPLACEMENT ).
2. NO- Intermittent failure, system is OK at this time.