Subaru 2002 IMPREZA Service Manual page 562

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
ENGINE (DIAGNOSTICS)
Step
4 CHECK HARNESS BETWEEN ENGINE
COOLANT TEMPERATURE SENSOR AND
ECM CONNECTOR.
Measure the voltage between engine coolant
temperature sensor connector and engine
ground.
Connector & terminal
(E8) No. 1 (+) — Engine ground ( − − − − ):
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. 2 — Engine ground:
Check
Is the voltage more than 4 V?
Is the resistance less than 5
Ω?
EN-130
Yes
Go to step 5. Repair the har-
ness and connec-
tor.
NOTE:
In this case, repair
the following:
• Open circuit in
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
(B21)
• Poor contact in
joint connector
(B83) or (B122)
Replace the Repair the har-
engine coolant ness and connec-
temperature sen- tor.
sor. <Ref. to FU-
NOTE:
31, Engine Cool-
In this case, repair
ant Temperature
the following:
Sensor.>
• Open circuit in
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
(B21)
• Poor contact in
joint connector
(B83) or (B122)
No