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Denso Air Conditioner Error Codes
39 error codes for Denso air conditioner models. Each links to the full diagnostic procedure from the service manual.
CodeDescription
ALDetection of unit stop signal from fire alarm systemALRMUnit stop signal detected from fire alarm systemASCondensate pump problemCFLoss of cooling detectionDFFreezing abnormalityE01WMC room thermistor (RTS1) failureE02Evaporator inlet air thermistor (RTS2) failureE03Condenser inlet air thermistor (ODS) failureE04Condenser thermistor (CTS1) failureE05Evaporator pipe inlet thermistor (CTS2) failureE06Evaporator pipe outlet thermistor (CTS3) failureE07Condensation overflow detected from optional condensate pumpE08WMC communication errorE09Evaporator fan motor lockedE1Room thermistor connection problemE10Condenser fan motor lockedE11STI module communication errorE14Compressor over currentE15Compressor lock failureE16Compressor phase interruption abnormalityMyPros+ Max
Get the full diagnostic procedure for any Denso air conditioner error code.
- Step-by-step tests with expected resistance, voltage, and continuity values
- Wiring diagram references and connector pinouts
- Verified part numbers when replacement is required
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E17Motor position detection abnormalityE18Input overcurrentE19Power device temperature abnormalityE2Freeze protection thermistor connection problemE20DC voltage abnormalityE21Power device damage abnormalityE22Circuit malfunctionE4Activation of protective deviceFLOvercurrent relay (thermal relay) protection activatedFTFreeze protection thermistor defectFZDefrost status / freeze condition indicated; evaporator outlet pipe temperature…HPActivation of high pressure switchIREvaporator fan motor reverse rotation abnormalityLOCKEDKey lock mode is activeOLCompressor overload relay activated due to high temperature build-up in…ORCondenser fan motor reverse rotation abnormalityPUCondensation overflow detectedRTRoom thermistor defectTANKThe drain tank switch has shut off the unit because the drain tank is full…