Subaru IMPREZA GD 2007 Series Manual page 224

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Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step
1 CHECK CURRENT DATA.
1) Start the engine.
2) Read the data of intake air temperature sen-
sor signal using 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)-32, Subaru Select Monitor.>
• General scan tool
For detailed operation procedure, refer to the
general scan tool operation manual.
2 CHECK HARNESS BETWEEN ECM AND
THE MASS AIR FLOW AND INTAKE AIR
TEMPERATURE SENSOR CONNECTORS.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from the ECM
and the mass air flow and intake air temperature
sensor.
3) Measure the resistance between ECM and
chassis ground.
Connector & terminal
(B135) No. 18 — Chassis ground:
Check
Is the intake air temperature
120°C (248°F) or higher?
Is the resistance 1 MΩ or
more?
EN(H4SO)(diag)-115
ENGINE (DIAGNOSTICS)
Yes No
Go to step 2. Even if the malfunc-
tion indicator light
illuminates, the cir-
cuit has returned to
a normal condition
at this time. Repro-
duce the fault con-
dition, and
reperform the
check.
NOTE:
In this case, there
may be a tempo-
rary connector
contact failure.
Replace the mass Repair short cir-
air flow and intake cuit of the harness
air temperature to ground between
sensor. <Ref. to the ECM and the
FU(H4SO)-28, mass air flow and
Mass Air Flow and intake air tempera-
Intake Air Temper- ture sensor.
ature Sensor.>