Subaru Legacy 2003 Service Manual page 1938

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
1 CHECK CURRENT DATA.
1) Start the engine.
2) Read the data of engine coolant tempera-
ture 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 ENGINE
COOLANT TEMPERATURE SENSOR AND
ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from engine cool-
ant temperature sensor.
3) Turn the ignition switch to ON.
4) Read the data of engine coolant tempera-
ture 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
120°C (248°F)
−40°C (−40°F)
EN(H4DOSTC)-99
ENGINE (DIAGNOSTICS)
Yes
Go to step 2. Repair the poor
contact.
NOTE:
In this case, repair
the following:
• Poor contact in
engine coolant
temperature sen-
sor
• Poor contact in
ECM
• Poor contact in
coupling connector
• Poor contact in
joint connector
Replace the Repair the ground
engine coolant short circuit in har-
temperature sen- ness between
sor. <Ref. to engine coolant
FU(H4DOSTC)- temperature sen-
28, Engine Cool- sor and ECM con-
ant Temperature nector.
Sensor.>
No