Fault Codes/Discovery Energy, LLC (Rehlko)/P0603Discovery Energy, LLC (Rehlko)P0603WarningGeneralWhat This Code MeansP0603Possible Causes•There is no saved EEPROM data.Suggested Actions1Clear the DTC code and turn the ECM power off. Wait fifteen minutes and check if the code is regenerated.2Replace the ECM. Refer to the Electronic Control Module section.Related Discovery Energy, LLC (Rehlko) Fault CodesP0604P0605P0563P0606P0509P0638P0508P0642P0335P0643P0172P0653Browse all Discovery Energy, LLC (Rehlko) fault codes→ASK RUDY ABOUT THIS FAULTGet a diagnosis walkthrough for P0603 on your specific Discovery Energy, LLC (Rehlko) unit — cited to the OEM manual, not a forum guess.Your question about P0603GET THE ANSWERFree account required — we'll bring your question with you.