Subaru Legacy 2004 Service Manual page 530

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step
5 CHECK HARNESS BETWEEN ENGINE
COOLANT TEMPERATURE SENSOR AND
ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Measure the resistance of harness
between engine coolant temperature sensor
connector and engine ground.
Connector & terminal
(E8) No. 1 — Engine ground:
Check
Is the resistance less than 5
&?
EN(H4SO 2.0)(diag)-98
Yes
Replace the Repair the har-
engine coolant ness and connec-
temperature sen- tor.
sor. <Ref. to
NOTE:
FU(H4SO 2.0)-20,
In this case, repair
Engine Coolant
the following:
Temperature Sen-
• Open circuit in
sor.>
harness between
ECM and engine
coolant tempera-
ture sensor con-
nector
• Poor contact in
engine coolant
temperature sen-
sor connector
• Poor contact in
ECM connector
• Poor contact in
coupling connector
• Poor contact in
joint connector
No