A P0538 code on your 2019 Chrysler 300 indicates a high voltage condition in the A/C evaporator temperature sensor circuit, typically indicating an open circuit condition.
High Voltage Interpretation
High voltage from the evaporator sensor circuit usually means the signal path is open—disconnected or broken. The climate control module sees reference voltage because the sensor isn't completing the circuit.
300 Climate Control
The 2019 Chrysler 300 features automatic climate control with dual-zone capability on many trims. The evaporator sensor is critical for maintaining proper cooling while preventing evaporator freeze-up.
Open Circuit Causes
The sensor may be disconnected from the harness. Wiring may be broken inside the HVAC housing. The sensor thermistor element may have failed open. Connector terminals may be corroded enough to create a high-resistance open. Rodent damage to wiring can create opens.
Diagnostic Process
Use wiTECH to verify high voltage reading. Check if voltage drops when simulating a closed circuit at the sensor connector. Test continuity from the sensor connector to the climate control module. If the circuit is intact, the sensor itself has failed open.