Subaru IMPREZA 2002 Service Manual page 445

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
ENGINE (DIAGNOSTICSI
Step
CHECK CURRENT DATA.
1)Start the engine.
2)Read the data of engine coolant temperature
sensor signal using Subaru Select Monitor or
OBD-ll general scan tool.
NOTE:
*Subaru Select Monitor
For detailed operation procedure, refer to the
"READ CURRENT DATA FOR ENGINE. <Ref.
to EN(S0HC)-32, Subaru Select Monitor.>
*OBD-ll general scan tool
For detailed operation procedures, refer to the
OBD-I1 General Scan Tool Instruction Manual.
! 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 temperature
sensor signal using Subaru Select Monitor or
OBD-I1 general scan tool.
NOTE:
*Subaru Select Monitor
For detailed operation procedure, refer to the
"READ CURRENT DATA FOR ENGINE. <Ref.
to EN(S0HC)-32, Subaru Select Monitor.>
*OBD-ll general scan tool
For detailed operation procedures, refer to the
OBD-II General Scan Tool Instruction Manual.
Check
j
the value greater than 150°C
302"F)?
s the value less than -40°C (-
IO'F)?
~
Yes
20 to step 2.
3eplace the
ingine coolant
emperature sen-
ior. <Ref. to
Engine Coolant
remperature Sen-
;or.>
W(SOHC)-27,
No
Repair poor con-
tact.
NOTE:
In this case, repaii
the following:
n
Poor contact in
engine coolant
temperature sen-
sor
n
Poor contact in
ECM
*
Poor contact in
coupling connector
Poor contact in
joint connector
(B122)
Repair ground
short circuit in har-
ness between
engine coolant
temperature sen-
sor and ECM con-
nector.
(B21)
EN(S0HC)-121