Fault Codes/Winco/129D-3Winco129D-3UnclassifiedCoolingWhat This Code MeansSubstitute value is taken for Oxi Cat temperature upstream sensorPossible Causes•Defect in the electrical signal of the Oxi Cat temperature upstream sensorRelated Winco Fault Codes129D-4251-1F 594 3198-2 157 0252-1F 623 669-4 108 3A6-269-3 105 4A6-E66-15 105 3A8-366-14 102 21A8-4Browse all Winco fault codes→ASK RUDY ABOUT THIS FAULTGet a diagnosis walkthrough for 129D-3 on your specific Winco unit — cited to the OEM manual, not a forum guess.TRY IT FREE