Fault Codes/Discovery Energy, LLC (Rehlko)/P0121Discovery Energy, LLC (Rehlko)P0121WarningGeneralWhat This Code MeansP0121Possible Causes•Problem with the TP sensor in the throttle body or the leads.Suggested Actions1Troubleshoot the TP sensor leads. Refer to the Throttle Position (TP) Sensor Troubleshooting section.2Replace the throttle body. Refer to the Air - Fuel Mixer, Adapter, and Throttle Body Assembly section.Related Discovery Energy, LLC (Rehlko) Fault CodesP0171P0172P0118P0335P0117P0508P0116P0509P0113P0563P0112P0603Browse all Discovery Energy, LLC (Rehlko) fault codes→ASK RUDY ABOUT THIS FAULTGet a diagnosis walkthrough for P0121 on your specific Discovery Energy, LLC (Rehlko) unit — cited to the OEM manual, not a forum guess.Your question about P0121GET THE ANSWERFree account required — we'll bring your question with you.