Diagnostic Procedure

WARNING: This page is about a different car, the 2013 Subaru Forester. However, it is still accessible from the selected car via links, so may be relevant.

DIAGNOSTIC PROCEDURE

Step	Check	Yes	No
1 CHECK CURRENT DATA. Start the engine. Read the value of «Coolant Temp.» using the Subaru Select Monitor or a general scan tool. NOTE: Subaru Select Monitor For detailed operation procedures, refer to "READ CURRENT DATA FOR ENGINE". < Refer to SUBARU SELECT MONITOR . > General scan tool For detailed operation procedures, refer to the general scan tool operation manual.	Is the value of «Coolant Temp.» 150°C (302°F) or more?	Go to step 2.	Even if DTC is detected, the circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again. NOTE: In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.
2 CHECK HARNESS BETWEEN ECM AND ENGINE COOLANT TEMPERATURE SENSOR CONNECTOR. Turn the ignition switch to OFF. Disconnect the connectors from ECM and engine coolant temperature sensor. Measure the resistance between ECM and chassis ground. Connector & terminal (B137) No. 22 - Chassis ground:	Is the resistance 1 MΩ or more?	Replace the engine coolant temperature sensor. < Refer to ENGINE COOLANT TEMPERATURE SENSOR . >	Repair short circuit in harness to ground between ECM and engine coolant temperature sensor connector.