Subaru Legacy 2003 Service Manual page 514

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
1 CHECK CURRENT DATA.
1) Start engine.
2) Read data of intake air temperature sensor
signal using Subaru Select Monitor or the
OBD-II general scan tool.
Does the measured value exceed the spec-
ified value?
NOTE:
•Subaru Select Monitor
For detailed operation procedure, refer to the
"READ CURRENT DATA FOR ENGINE".
<Ref. to EN(H4SO)-32, Subaru Select Moni-
tor.>
•OBD-II general scan tool
For detailed operation procedure, refer to the
OBD-II General Scan Tool Instruction Manual.
2 CHECK HARNESS BETWEEN INTAKE AIR
TEMPERATURE SENSOR AND ECM CON-
NECTOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from intake air tem-
perature and pressure sensor.
3) Turn ignition switch to ON.
4) Read data of intake air temperature sensor
signal using Subaru Select Monitor or the
OBD-II general scan tool.
Is the measured value less than the speci-
fied value?
NOTE:
•Subaru Select Monitor
For detailed operation procedure, refer to the
"READ CURRENT DATA FOR ENGINE".
<Ref. to EN(H4SO)-32, Subaru Select Moni-
tor.>
•OBD-II general scan tool
For detailed operation procedure, refer to the
OBD-II General Scan Tool Instruction Manual.
Value
120°C (248°F)
−40°C (−40°F)
EN(H4SO)-117
ENGINE (DIAGNOSTICS)
Yes
Go to step 2. Repair poor con-
tact.
NOTE:
In this case, repair
the following:
• Poor contact in
intake air tempera-
ture sensor
• Poor contact in
ECM
• Poor contact in
coupling connector
• Poor contact in
joint connector
Replace intake air Repair ground
temperature sen- short circuit in har-
sor. <Ref. to ness between
FU(H4SO)-33, intake air tempera-
REMOVAL, Intake ture sensor and
Air Temperature ECM connector.
Sensor.>
No