The powertrain or climate control module has detected an electrical fault in the air conditioning evaporator temperature sensor circuit. This sensor measures evaporator core temperature to prevent freeze-up and regulate compressor operation. The code sets when the signal voltage or resistance falls outside the expected range for a calibrated period of time.
The thermistor or sensing element inside the sensor can drift out of calibration or fail internally, producing an out-of-range signal that the module cannot interpret.
The low-voltage signal wires near the evaporator case may become rubbed through, pinched, or melted, resulting in opens, shorts-to-ground, or shorts-to-voltage.
Moisture intrusion, oxidation, or terminal fretting at the sensor plug or bulkhead connector can increase resistance and distort the circuit reading.
Water ingress or excessive frost formation at the sensor tip can create temporary shorts or prevent the sensor from accurately reporting evaporator temperature.
An internal failure in the PCM or HVAC control module is a rare cause; it should only be considered after the sensor and entire circuit have been proven mechanically and electrically sound.
Yes, but expect impaired A/C performance or automatic compressor shutdown to prevent evaporator freeze-up.
The control system cannot confirm evaporator temperature, so it disables the compressor as a protective measure to avoid ice blockage.
No. Control module failure is an uncommon cause of P0535. Most instances are resolved by replacing the evaporator temperature sensor or repairing its wiring. PCM replacement is usually unnecessary and is a commonly misdiagnosed repair for this code.
No. This code relates to the climate control system and does not alter fuel injection, ignition timing, or engine power output.