Subaru Legacy 2002 Service Manual page 1889

DIAGNOSTIC PROCEDURE FOR NO-DIAGNOSTIC TROUBLE CODE (DTC)
Automatic Transmission (Diagnostics)
H: CHECK INHIBITOR SWITCH.
S004794F20
DIAGNOSIS:
Input signal circuit of inhibitor switch is open or shorted.
TROUBLE SYMPTOM:
¼ Shift characteristics are erroneous.
¼ Engine brake is not effected when selector lever is in "3" range.
¼ Engine brake is not effected when selector lever is in "2" range.
¼ Engine brake is not effected when selector lever is in "1" range.
AT-120