Subaru Legacy 2003 Service Manual page 1932

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.
Does the measured value exceed the spec-
ified value?
NOTE:
For detailed operation procedure, refer to the
"READ CURRENT DATA FOR ENGINE". <Ref.
to EN(H4DOSTC)-26, Subaru Select Monitor.>
2 CHECK HARNESS BETWEEN MASS AIR
FLOW AND INTAKE AIR TEMPERATURE
SENSOR AND ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from mass air
flow and intake air temperature sensor.
3) Turn the ignition switch to ON.
4) Read the data of intake air temperature
sensor signal using Subaru Select Monitor.
Is the measured value less than the speci-
fied value?
NOTE:
For detailed operation procedure, refer to the
"READ CURRENT DATA FOR ENGINE". <Ref.
to EN(H4DOSTC)-26, Subaru Select Monitor.>
Value
55°C (131°F)
−36°C (−97°F)
EN(H4DOSTC)-93
ENGINE (DIAGNOSTICS)
Yes
Go to step 2. Repair the poor
contact.
NOTE:
In this case, repair
the following:
• Poor contact
mass air flow and
intake air tempera-
ture sensor
• Poor contact in
ECM
• Poor contact in
joint connector
Replace the mass Repair the ground
air flow and intake short circuit in har-
air temperature ness between
sensor. <Ref. to mass air flow and
FU(H4DOSTC)- intake air tempera-
33, Mass Air Flow ture sensor and
and Intake Air ECM connector.
Temperature Sen-
sor.>
No