Subaru 2009 IMPREZA Service Manual page 1378

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step
1 CHECK CURRENT DATA.
1) Start the engine.
2) Read the data of fuel temperature sensor
signal using Subaru Select Monitor.
NOTE:
For detailed operation procedures, refer to
"READ CURRENT DATA FOR ENGINE". <Ref.
to EN(H4DOTC)(diag)-34, Subaru Select Moni-
tor.>
2 CHECK HARNESS BETWEEN ECM AND
FUEL TEMPERATURE SENSOR CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from ECM and
fuel temperature sensor.
3) Measure the resistance between ECM and
chassis ground.
Connector & terminal
(B135) No. 17 — Chassis ground:
Check
Is the temperature 120°C
(248°F) or higher?
Is the resistance 1 M or
more?
EN(H4DOTC)(diag)-157
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 fuel Repair the ground
temperature sen- short circuit of har-
sor. <Ref. to ness between
EC(H4DOTC)-16, ECM and fuel
Fuel Temperature pump connector.
Sensor.>