Subaru 2009 IMPREZA Service Manual page 625

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step
1 CHECK OUTPUT SIGNAL OF ECM.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B136) No. 17 (+) — Chassis ground (–):
2 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) Measure the resistance between the drain
valve connector and chassis ground.
Connector & terminal
(R86) No. 2 — Chassis ground:
3 CHECK HARNESS BETWEEN ECM AND
DRAIN VALVE.
Measure the resistance of harness between
ECM and drain valve connector.
Connector & terminal
(B136) No. 17 — (R86) No. 2:
4 CHECK DRAIN VALVE.
Measure the resistance between drain valve
terminals.
Terminals
No. 1 — No. 2:
5 CHECK POWER SUPPLY TO DRAIN VALVE.
1) Turn the ignition switch to ON.
2) Measure the voltage between drain valve
and chassis ground.
Connector & terminal
(R86) No. 1 (+) — Chassis ground (–):
Check
Is the voltage 10 V or more?
Is the resistance 1 M or
more?
Is the resistance less than 1 ? Go to step 4.
Is the resistance 10 — 100 ? Go to step 5.
Is the voltage 10 V or more?
EN(H4SO)(diag)-208
Yes No
Repair the poor Go to step 2.
contact of ECM
connector.
Go to step 3. Repair the ground
short circuit of har-
ness between
ECM and drain
valve connector.
Repair the harness
and connector.
NOTE:
In this case, repair
the following item:
• Open circuit of
harness between
ECM and
valve connector
• Poor contact of
coupling connector
Replace the drain
valve. <Ref. to
EC(H4SO)-19,
Drain Valve.>
Repair the poor Repair the harness
contact of drain and connector.
valve connector.
NOTE:
In this case, repair
the following item:
• Open circuit in
harness between
main relay connec-
tor and drain valve
connector
• Poor contact of
coupling connector
• Poor contact of
main relay connec-
tor
drain