Fault Codes/Cummins/239Cummins239UnclassifiedGeneralWhat This Code MeansOil temperature sensor reading out of rangePossible Causes•Oil temperature sensor output is out of range (OOR), high or lowRelated Cummins Fault Codes245252238254236285234286226 THRU 233379225418Browse all Cummins fault codes→ASK RUDY ABOUT THIS FAULTGet a diagnosis walkthrough for 239 on your specific Cummins unit — cited to the OEM manual, not a forum guess.Your question about 239GET THE ANSWERFree account required — we'll bring your question with you.