DTC P0197 Engine Oil Temperature Sensor Low: Wiring Diagram

Engine electrical system, 2.5 L model (without push button start). See appropriate SYSTEM WIRING DIAGRAM article.
Engine electrical system, 2.5 L model (with push button start). See appropriate SYSTEM WIRING DIAGRAM article.

Fig 1: Engine Oil Temperature Sensor - Circuit Diagram
Courtesy of SUBARU OF AMERICA, INC.

DIAGNOSTIC PROCEDURE

Step	Check	Yes	No
1 CHECK CURRENT DATA. Start the engine. Read the value of «Oil Temperature» using Subaru Select Monitor. NOTE: For detailed operation procedures, refer to "READ CURRENT DATA FOR ENGINE". Refer to SUBARU SELECT MONITOR .	Is the value of «Oil Temperature » 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 OIL TEMPERATURE SENSOR CONNECTOR. Turn the ignition switch to OFF. Disconnect the connectors from the ECM and engine oil temperature sensor. Measure the resistance between ECM and chassis ground. Connector & terminal (B134) No. 20 - Chassis ground:	Is the resistance 1 MΩ or more?	Replace the engine oil temperature sensor. Refer to ENGINE OIL TEMPERATURE SENSOR .	Repair the short circuit to ground in the harness between the ECM and engine oil temperature sensor connector.