Subaru 2002 IMPREZA Service Manual page 553

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
OBD-II general scan tool.
NOTE:
•Subaru Select Monitor
For detailed operation procedure, refer to the
"READ CURRENT DATA FOR ENGINE".
<Ref. to EN-34, Subaru Select Monitor.>
•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 AND PRESSURE SENSOR
AND ECM CONNECTOR.
1)Turn the ignition switch to OFF.
2)Disconnect the connector from intake air
temperature and pressure sensor.
3)Turn the ignition switch to ON.
4)Read the data of intake air temperature sen-
sor signal using Subaru Select Monitor or the
OBD-II general scan tool.
NOTE:
•Subaru Select Monitor
For detailed operation procedure, refer to the
"READ CURRENT DATA FOR ENGINE".
<Ref. to EN-34, Subaru Select Monitor.>
•OBD-II general scan tool
For detailed operation procedure, refer to the
OBD-II General Scan Tool Instruction Manual.
Check
Is the value greater than 120°C
(248°F)?
Is the value less than −40°C
(−40°F)?
EN-121
ENGINE (DIAGNOSTICS)
Yes
Go to step 2. Repair the poor
contact.
NOTE:
In this case, repair
the following:
• Poor contact in
intake air tempera-
ture and pressure
sensor
• Poor contact in
ECM
• Poor contact in
coupling connector
(B21)
• Poor contact in
joint connector
(B83), (B122)
Replace the intake Repair the ground
air temperature short circuit in har-
and pressure sen- ness between
sor. <Ref. to FU- intake air tempera-
37, Intake Air ture sensor and
Temperature and ECM connector.
Pressure Sensor.>
No