Subaru Legacy 2002 Service Manual page 3209

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC) (LHD
MODEL)
HVAC System (Auto A/C) (Diagnostics)
D: DTC 25 OR –25 (SUNLOAD SENSOR)
S001809K29
TROUBLE SYMPTOM:
¼ Sensor identified that sunlight is at maximum. Then, A/C system is controlled to COOL side.
¼ Sensor identified that sunlight is at minimum. Then, A/C system is controlled to HOT side.
NOTE:
When the sunload sensor is checked inside the passenger compartment or in the shade, DTC "25" may
appear on the indicator. Always check the sunload sensor in a place where it senses direct sunlight.
AC-66