Subaru Legacy 2002 Service Manual page 1336

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
No.
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.
NOTE:
¼ Subaru Select Monitor
For detailed operation procedure, refer to the
"READ CURRENT DATA FOR ENGINE".
<Ref. to EN(H6)-38, Subaru Select Monitor.>
¼ 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 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.
NOTE:
¼ Subaru Select Monitor
For detailed operation procedure, refer to the
"READ CURRENT DATA FOR ENGINE".
<Ref. to EN(H6)-38, Subaru Select Monitor.>
¼ OBD-II general scan tool
For detailed operation procedure, refer to the
OBD-II General Scan Tool Instruction Manual.
Step
Is the value greater than
120°C (248°F)?
Is the value less than
−40°C (−40°F)?
EN(H6)-129
Check Yes
Go to step 2.
Replace intake air
temperature sen-
sor. <Ref. to
FU(H6)-35, Intake
Air Temperature
Sensor.>
Engine (DIAGNOSTICS)
No
Repair poor con-
tact.
NOTE:
In this case,
repair the follow-
ing:
¼ Poor contact in
intake air tem-
perature sensor
¼ Poor contact in
ECM
¼ Poor contact in
coupling connec-
tor
¼ Poor contact in
joint connector
Repair ground
short circuit in
harness between
intake air tem-
perature sensor
and ECM connec-
tor.