Subaru 2009 IMPREZA Service Manual page 1337

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step
1 CHECK CURRENT DATA.
1) Start the engine.
2) Read the data of intake manifold absolute
pressure signal using Subaru Select Monitor or
general scan tool.
NOTE:
• Subaru Select Monitor
For detailed operation procedures, refer to
"READ CURRENT DATA FOR ENGINE". <Ref.
to EN(H4DOTC)(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
MANIFOLD ABSOLUTE PRESSURE SEN-
SOR CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from manifold
absolute pressure sensor.
3) Start the engine.
4) Read the data of intake manifold absolute
pressure signal using Subaru Select Monitor or
general scan tool.
NOTE:
• Subaru Select Monitor
For detailed operation procedures, refer to
"READ CURRENT DATA FOR ENGINE". <Ref.
to EN(H4DOTC)(diag)-34, Subaru Select Moni-
tor.>
• General scan tool
For detailed operation procedures, refer to the
general scan tool operation manual.
3 CHECK HARNESS BETWEEN ECM AND
MANIFOLD ABSOLUTE PRESSURE SEN-
SOR CONNECTOR.
1) Turn the ignition switch to OFF.
2) Measure the resistance of harness between
manifold absolute pressure sensor connector
and engine ground.
Connector & terminal
(E21) No. 1 — Engine ground:
4 CHECK POOR CONTACT.
Check for poor contact of manifold absolute
pressure sensor connector.
Check
Is the measured value 119.5 kPa
(896.5 mmHg, 35.29 inHg) or
more?
Is the measured value 119.5 kPa
(896.5 mmHg, 35.29 inHg) or
more?
Is the resistance less than 5 ? Go to step 4.
Is there poor contact of mani-
fold absolute pressure sensor
connector?
EN(H4DOTC)(diag)-116
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.
Repair the short Go to step 3.
circuit to power in
harness between
ECM and manifold
absolute pressure
sensor connector.
Repair the harness
and connector.
NOTE:
In this case, repair
the following item:
• Open circuit of
harness between
ECM and manifold
absolute pressure
sensor connector.
• Poor contact of
ECM connector
• Poor contact of
coupling connector
Repair the poor Replace the mani-
contact of mani- fold absolute pres-
fold absolute pres- sure sensor. <Ref.
sure sensor to FU(H4DOTC)-
connector. 40, Manifold Abso-
lute Pressure Sen-
sor.>