P0603
DTC P0603: ECM/PCM Internal Control Module Keep Alive Memory (KAM) Error1. Turn the ignition switch ON (II).
2. Clear the DTC with the HDS.
3. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0603 indicated?
YES - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.
NO - Intermittent failure, system is OK at this time.