DTC P0197 Engine Oil Temperature Sensor Low: Wiring Diagram

Fig 1: Engine Oil Temperature Sensor Wiring Diagram (Low)

Courtesy of SUBARU OF AMERICA, INC.

Step	Check	Yes	No
1 CHECK CURRENT DATA. Start the engine. Read the data of the oil temperature sensor signal using the Subaru Select Monitor or 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 oil temperature 215°C (419°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 OIL TEMPERATURE SENSOR CONNECTOR. Turn the ignition switch to OFF. Disconnect the connector from ECM and oil temperature sensor. Measure the resistance between ECM and chassis ground. Connector & terminal (B137) No. 21 - Chassis ground:	Is the resistance 1 MΩ or more?	Replace the oil temperature sensor. Refer to OIL TEMPERATURE SENSOR Oil Temperature Sensor.	Repair the short circuit to ground in harness between ECM and oil temperature sensor connector.