Subaru 2009 IMPREZA Service Manual page 590

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step
1 CHECK CURRENT DATA.
1) Start the engine.
2) Read the data of the oil temperature sensor
signal using the Subaru Select Monitor or gen-
eral scan tool.
NOTE:
• Subaru Select Monitor
For detailed operation procedures, refer to
"READ CURRENT DATA FOR ENGINE". <Ref.
to EN(H4SO)(diag)-34, Subaru Select Moni-
tor.>
• General scan tool
For detailed operation procedures, refer to the
general scan tool operation manual.
2 CHECK HARNESS BETWEEN ECM AND OIL
TEMPERATURE SENSOR CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM and oil
temperature sensor.
3) Measure the resistance between ECM and
chassis ground.
Connector & terminal
(B134) No. 23 — Chassis ground:
Check
Is the oil temperature 215°C
(419°F) or more?
Is the resistance 1 M or
more?
EN(H4SO)(diag)-173
ENGINE (DIAGNOSTICS)
Yes No
Go to step 2. Even if DTC is
detected, the cir-
cuit has returned to
a normal condition
at this time. Repro-
duce the failure,
and then perform
the diagnosis
again.
NOTE:
In this case, tem-
porary poor con-
tact of connector
may be the cause.
Replace the oil Repair the short
temperature sen- circuit to ground in
sor. <Ref. to harness between
FU(H4SO)-40, Oil ECM and oil tem-
Temperature Sen- perature sensor
sor.> connector.