Fault Codes/Rehlko/3515Rehlko3515UnclassifiedCoolingWhat This Code MeansOvertemperature warning; Short circuitPossible Causes•DEF tank (temperature sensor at suction position)Related Rehlko Fault Codes4342 44360 23031 154360 33031 44360 43031 34360 53031 04360 151153 94360 31Browse all Rehlko fault codes→ASK RUDY ABOUT THIS FAULTGet a diagnosis walkthrough for 3515 on your specific Rehlko unit — cited to the OEM manual, not a forum guess.Your question about 3515GET THE ANSWERFree account required — we'll bring your question with you.