Subaru 2009 IMPREZA Service Manual page 627

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step
1 CHECK HARNESS BETWEEN ECM AND
DRAIN VALVE.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from the ECM
and drain valve.
3) Turn the ignition switch to ON.
4) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B136) No. 17 (+) — Chassis ground (–):
2 CHECK DRAIN VALVE.
1) Turn the ignition switch to OFF.
2) Measure the resistance between drain valve
terminals.
Terminals
No. 1 — No. 2:
Check
Is the voltage 10 V or more?
Is the resistance less than 1 ? Replace the drain
EN(H4SO)(diag)-210
Yes No
Repair the short Go to step 2.
circuit to power in
the harness
between ECM and
drain valve con-
nector.
Repair the poor
valve. <Ref. to contact of ECM
EC(H4SO)-19, connector.
Drain Valve.>