DTC B1431 In-Vehicle (Post Evaporator) Temperature Sensor Circuit Short-Circuit

DTC detecting condition: 

In-vehicle sensor circuit is shorted.

Trouble symptom: 

In-vehicle air temperature is falsely recognized as 25°C (77°F), and the compartment temperature is adjusted.

Wiring diagram: 

Air conditioning system Ref. to WIRING SYSTEM>Air Conditioning System>WIRING DIAGRAM .

Fig 1: Air Conditioning System Wiring Diagram (Temperature Sensor Short Circuit)

Courtesy of SUBARU OF AMERICA, INC.

Fig 2: Air Conditioning System Temperature Sensor Short Circuit Diagnosis Flowchart

Courtesy of SUBARU OF AMERICA, INC.