DTC P0030 Ho2S Heater Control Circuit (Bank 1 Sensor 1): Wiring Diagram

WARNING: This page is about a different variant/trim than selected.

Engine Electrical System ENGINE TYPE EJ (WITHOUT PUSH BUTTON START) <Ref. to 2.5L TURBO (WITHOUT PUSH BUTTON START), WIRING DIAGRAM, Engine Electrical System.>
Engine Electrical System ENGINE TYPE EJ (WITH PUSH BUTTON START) <Ref. to 2.5L TURBO (WITH PUSH BUTTON START), WIRING DIAGRAM, Engine Electrical System.>

Fig 1: HO2S Heater Control (Bank 1 Sensor 1) - Wiring Diagram

G10265804

Courtesy of SUBARU OF AMERICA, INC.

DIAGNOSTIC PROCEDURE

Step	Check	Yes	No
1 CHECK HARNESS BETWEEN ECM AND FRONT OXYGEN (A/F) SENSOR CONNECTOR. Start and warm up the engine. Turn the ignition switch to OFF. Disconnect the connectors from ECM and front oxygen (A/F) sensor. Measure the resistance of harness between ECM connector and front oxygen (A/F) sensor connector. Connector & terminal (B136) No. 5 - (B379) No. 2: (B136) No. 6 - (B379) No. 2: (B136) No. 18 - (B379) No. 3: (B136) No. 19 - (B379) No. 4:	Is the resistance less than 1 Ω?	Go to step 2 .	Repair the open circuit of harness between ECM connector and front oxygen (A/F) sensor connector.
2 CHECK FRONT OXYGEN (A/F) SENSOR. Measure the resistance between front oxygen (A/F) sensor terminals. Terminals No. 1 - No. 2:	Is the resistance less than 2 - 3 Ω	Go to step 3 .	Replace the front oxygen (A/F) sensor. <Ref. to FRONT OXYGEN (A/F) SENSOR .>
3 CHECK FOR POOR CONTACT. Check for poor contact of ECM and front oxygen (A/F) sensor connector.	Is there poor contact of ECM or front oxygen (A/F) sensor connector?	Repair the poor contact of ECM or front oxygen (A/F) sensor connector.	Replace the front oxygen (A/F) sensor. <Ref. to FRONT OXYGEN (A/F) SENSOR .>