Subaru 2009 IMPREZA Service Manual page 892

Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
CO:DTC P1491 POSITIVE CRANKCASE VENTILATION (BLOW-BY) FUNCTION
PROBLEM
1. OUTLINE OF DIAGNOSIS
Detect the blow-by hose disconnection abnormality.
Judge as NG when the diagnosis terminal voltage is high.
2. COMPONENT DESCRIPTION
(1)
(1) Engine control module (ECM)
(2) Detecting circuit
3. ENABLE CONDITION
Secondary Parameters
None
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
(4)
(2)
(3) PCV diagnosis connector
Enable Conditions
GD(H4SO)-168
(3)
(4) 5 V
E
EN-01790