P0539A/C Evaporator Temperature Sensor Circuit Intermittent
- Generic OBD-II code · Powertrain
- How the car detects it
- The evaporator temperature sensor, an NTC thermistor behind the evaporator, prevents icing: near 0–3 °C the compressor is switched off or reduced. Usually the climate module reads it and reports body codes; P0535–P0539 only arise where the engine module controls the compressor and reads the sensor. P0539 means short dropouts or jumps in the signal that do not add up to a lasting low or high fault – usually a loose contact or condensate corrosion at the connector; the compressor may switch off at times. No manufacturer document available to us uses this code; the description follows CARB's input component rules.
- What you may notice
- Air conditioning failing at times
- Cooling fluctuates
- Usually no check engine light
- Likely causes
- LikelyLoose contact or corrosion at the connector
- PossibleBroken wire from movement or chafing
- PossibleSensor with internal intermittent contact
- Repair
- Medium · Often possible to do yourself.Typical cost: €20 – €400
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.