Subaru IMPREZA 2002 Service Manual page 511

OIL PUMP
POWER ASSISTED SYSTEM (POWER STEERING)
(4) If it is within the specified value, measure
the steering effort. <Ref. to PS-78, MEASURE-
MENT OF STEERING EFFORT, INSPECTION,
General Diagnostic Table.> If it is not within
specified value, replace the control valve itself or
control valve and pinion as a single unit with new
ones.
PS-69