P0539 OBD II Trouble Code A/C Evaporator Temperature Sensor Circuit Intermittent

How to quickly diagnose, repair, and info on causes and symptoms of a P0539 air conditioning evaporator temperature sensor circuit intermittent malfunction code.

Symptoms of P0539 OBD II Trouble Code

  • No cold air blowing from the air vents
  • Fan air temperature erratic/fluctuating
  • A/C compressor clutch not engaging
  • HVAC system not functioning as desired

Common Causes of P0539 OBD II Trouble Code

  • Defective or damaged A/C Evaporator core
  • Defective A/C Evaporator Temperature sensor
  • Defective ECM ( Engine Control Module)
  • Wiring issue within the sensor's circuit
  • Wiring harness connector issue
  • Intermittent electrical connection
  • Internal resistance (corrosion, damaged harness, overheated circuit, etc..)

Severity of P0539 OBD II Trouble Code

Given the fact that your entire HVAC system was designed with the sole purpose of keeping humans more comfortable, severity here is set to the lowest possible setting. Complete malfunction of the HVAC system would pose pretty much zero threat to your safety. That being said, if you value comfort like myself, you will need to address this problem immediately.