Subaru Forester 2004 Service Manual page 96

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
or the OBD-II general scan tool.
NOTE:
• Subaru Select Monitor
For detailed operation procedure, refer to
"READ CURRENT DATA SHOWN ON DIS-
PLAY FOR ENGINE". <Ref. to EN(H4DOTC
2.5)-27, Subaru Select Monitor.>
• OBD-II general scan tool
For detailed operation procedures, refer to the
OBD-II General Scan Tool Operation Manual.
2 CHECK HARNESS BETWEEN ENGINE
COOLANT TEMPERATURE SENSOR AND
ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from the engine
coolant temperature sensor.
3) Turn the ignition switch to ON.
4) Read the data of engine coolant tempera-
ture sensor signal using Subaru Select Monitor
or the OBD-II general scan tool.
NOTE:
• Subaru Select Monitor
For detailed operation procedure, refer to
"READ CURRENT DATA SHOWN ON DIS-
PLAY FOR ENGINE". <Ref. to EN(H4DOTC
2.5)-27, Subaru Select Monitor.>
• OBD-II general scan tool
For detailed operation procedures, refer to the
OBD-II General Scan Tool Operation Manual.
Check
Is engine coolant temperature
more than 120°C (248°F)?
Is the temperature more than
−40°C (−40°F)?
EN(H4DOTC 2.5)-95
ENGINE (DIAGNOSTIC)
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 engine Repair ground short
coolant tempera- circuit in harness
ture sensor. <Ref. between engine
to FU(H4DOTC coolant tempera-
2.5)-26, Engine ture sensor and
Coolant Tempera- ECM connector.
ture Sensor.>
No