Subaru 2009 IMPREZA Service Manual page 513

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step
1 CHECK HARNESS BETWEEN ECM AND
VARIABLE VALVE LIFT DIAGNOSIS OIL
PRESSURE SWITCH.
1) Warm up the engine.
2) Turn the ignition switch to OFF.
3) Disconnect the connectors from the ECM
and variable valve lift diagnosis oil pressure
switch.
4) Measure the resistance of harness between
ECM and variable valve lift diagnosis oil pres-
sure switch connector.
Connector & terminal
(B134) No. 32 — (E72) No. 1:
2 CHECK HARNESS BETWEEN ECM AND
VARIABLE VALVE LIFT DIAGNOSIS OIL
PRESSURE SWITCH.
Measure the resistance between variable valve
lift diagnosis oil pressure switch connector and
engine ground.
Connector & terminal
(E72) No. 1 — Engine ground:
3 CHECK HARNESS BETWEEN ECM AND
VARIABLE VALVE LIFT DIAGNOSIS OIL
PRESSURE SWITCH.
1) Turn the ignition switch to ON.
2) Measure the voltage between variable valve
lift diagnosis oil pressure switch connector and
engine ground.
Connector & terminal
(E72) No. 1 (+) — Engine ground (–):
4 CHECK DTC.
1) Perform the Clear Memory Mode.
2) After idling the engine, check the DTC.
NOTE:
For detailed procedures, refer to "Clear Memory
Mode". <Ref. to EN(H4SO)(diag)-55, Clear
Memory Mode.>
5 CHECK DTC.
1) Perform the Clear Memory Mode.
2) After idling the engine, check the DTC.
NOTE:
For detailed procedures, refer to "Clear Memory
Mode". <Ref. to EN(H4SO)(diag)-55, Clear
Memory Mode.>
Check
Is the resistance less than 1 ? Go to step 2.
Is the resistance 1 M or
more?
Is the voltage 10 V or more?
Is DTC displayed?
Is DTC displayed?
EN(H4SO)(diag)-96
Yes No
Repair the harness
and connector.
NOTE:
In this case, repair
the following item:
• Open circuit in
harness between
ECM and variable
valve lift diagnosis
oil pressure switch
connector
• Poor contact of
coupling connector
Go to step 3. Repair the ground
short circuit of har-
ness between
ECM and variable
valve lift diagnosis
oil pressure switch
connector.
Repair the short Go to step 4.
circuit to power of
the harness
between ECM and
variable valve lift
diagnosis oil pres-
sure switch con-
nector.
Replace the oil End.
switching solenoid
valve. <Ref. to
ME(H4SO)-93, Oil
Switching Solenoid
Valve.> Go to step
5.
Check for oil rout- End.
ing.