Subaru Legacy 2002 Service Manual page 886

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
No.
1 CHECK HARNESS BETWEEN ENGINE
COOLANT TEMPERATURE SENSOR AND
ECM CONNECTOR.
1) Turn ignition switch to OFF.
2) Remove generator.
3) Disconnect connector from engine coolant
temperature sensor.
4) Measure voltage between engine coolant
temperature sensor connector and engine
ground.
Connector & terminal
(E8) No. 1 (+) — Engine ground (−):
2 CHECK HARNESS BETWEEN ENGINE
COOLANT TEMPERATURE SENSOR AND
ECM CONNECTOR.
1) Turn ignition switch to ON.
2) Measure voltage between engine coolant
temperature sensor connector and engine
ground.
Connector & terminal
(E8) No. 1 (+) — Engine ground (−):
3 CHECK HARNESS BETWEEN ENGINE
COOLANT TEMPERATURE SENSOR AND
ECM CONNECTOR.
Measure voltage between engine coolant tem-
perature sensor connector and engine
ground.
Connector & terminal
(E8) No. 1 (+) — Engine ground (−):
Step
Is the voltage more than 10
V?
Is the voltage more than 10
V?
Is the voltage more than 4
V?
EN(w/oOBD)-75
Check Yes
Repair battery
short circuit in
harness between
ECM and engine
coolant tempera-
ture sensor con-
nector.
Repair battery
short circuit in
harness between
ECM and engine
coolant tempera-
ture sensor con-
nector.
Go to step 4.
Engine (Diagnostics)
No
Go to step 2.
Go to step 3.
Repair harness
and connector.
NOTE:
In this case,
repair the follow-
ing:
¼ Open circuit in
harness between
ECM and engine
coolant tempera-
ture sensor con-
nector
¼ Poor contact in
engine coolant
temperature sen-
sor connector
¼ Poor contact in
ECM connector
¼ Poor contact in
coupling connec-
tor (B21)