Subaru LEGACY 2006 Manual page 156

asieps_tobira.book 119 ページ ２００９年１０月２６日 月曜日 午前９時１６分
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step
1 CHECK CURRENT DATA.
1) Start the engine.
2) Read the data of intake air temperature
sensor signal using Subaru Select Monitor or
general scan tool.
NOTE:
• Subaru Select Monitor
For detailed operation procedure, refer to
"READ CURRENT DATA FOR ENGINE". <Ref.
to EN(H4SO)(diag)-26, Subaru Select Moni-
tor.>
• General scan tool
For detailed operation procedure, refer to the
general scan tool operation manual.
2 CHECK HARNESS BETWEEN INTAKE AIR
TEMPERATURE SENSOR AND ECM CON-
NECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from intake air
temperature sensor.
3) Measure the voltage between intake air
temperature sensor connector and engine
ground.
Connector & terminal
(B3) No. 4 (+) — Engine ground (– ):
3 CHECK HARNESS BETWEEN INTAKE AIR
TEMPERATURE SENSOR AND ECM CON-
NECTOR.
1) Turn the ignition switch to ON.
2) Measure the voltage between intake air
temperature sensor connector and engine
ground.
Connector & terminal
(B3) No. 4 (+) — Engine ground (–):
4 CHECK HARNESS BETWEEN INTAKE AIR
TEMPERATURE SENSOR AND ECM CON-
NECTOR.
Measure the voltage between intake air tem-
perature sensor connector and engine ground.
Connector & terminal
(B3) No. 4 (+) — Engine ground (–):
Check
Is the intake air temperature
less than –40°C (–40°F) ?
Is the voltage more than 10 V? Repair the battery
Is the voltage more than 10 V? Repair the battery
Is the voltage more than 3 V?
EN(H4SO)(diag)-119
ENGINE (DIAGNOSTICS)
Yes No
Go to step 2. Repair the poor
contact.
NOTE:
In this case, repair
the following item:
• Poor contact in
intake air tempera-
ture sensor
• Poor contact in
ECM
• Poor contact of
coupling connector
• Poor contact of
joint connector
Go to step 3.
short circuit of har-
ness between
intake air tempera-
ture sensor and
ECM connector.
Go to step 4.
short circuit of har-
ness between
intake air tempera-
ture sensor and
ECM connector.
Go to step 5. Repair the har-
ness and connec-
tor.
NOTE:
In this case, repair
the following item:
• Open circuit in
harness between
intake air tempera-
ture sensor and
ECM connector
• Poor contact in
intake air tempera-
ture sensor
• Poor contact in
ECM
• Poor contact of
coupling connector
• Poor contact of
joint connector