P0603

DTC P0603: ECM/PCM Internal Circuit Malfunction (Keep Alive Memory (KAM) Error) (2005-2006 models)

1. Turn the ignition switch ON (II).
2. Clear the DTC with the HDS.
3. Wait for 1 second.
4. Check for Temporary DTCs or DTCs with the HDS.

Are any Temporary DTCs or DTCs 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.