ENGINE (DIAGNOSTICS)(H4SO) > Diagnostic Procedure with Diagnostic Trouble Code (DTC)

DTC P0131 O2 SENSOR CIRCUIT LOW VOLTAGE (BANK 1 SENSOR 1)

DTC DETECTING CONDITION:

Immediately at fault recognition

CAUTION:

After repairing or replacing the defective part, perform the Clear Memory Mode and Inspection Mode .

WIRING DIAGRAM:

STEPCHECKYESNO

1.CHECK FRONT OXYGEN (A/F) SENSOR CONNECTOR AND COUPLING CONNECTOR.

Does water enter the connector?

Remove water thoroughly from the connector.

2.CHECK HARNESS BETWEEN ECM AND FRONT OXYGEN (A/F) SENSOR CONNECTOR.

1) Turn the ignition switch to OFF.

2) Disconnect the connector from ECM and front oxygen (A/F) sensor connector.

3) Measure the resistance of harness between ECM and chassis ground.

Connector & terminal

(B135) No. 8 — Chassis ground:

(B135) No. 9 — Chassis ground:

Is the resistance 1 MΩ or more?

Replace the front oxygen (A/F) sensor.

Repair the ground short circuit of harness between ECM and front oxygen (A/F) sensor connector.