Wiring Diagram:

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

Turn the ignition switch to OFF.

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

Measure the resistance of harness between ECM and front oxygen (A/F) sensor connector.

Connector & terminal 

(B134) No. 26 - (E47) No. 2: 

(B134) No. 33 - (E47) No. 1: 

Is the measured value less than 1 O?

YES. Go to next step. 

NO 

• Repair the harness and connector.
  NOTE: In this case, repair the following:

  • Open circuit in harness between ECM and front oxygen (A/F) sensor connector
  • Poor contact in front oxygen (A/F) sensor connector
  • Poor contact in ECM connector

CHECK POOR CONTACT. 

Check poor contact in front oxygen (A/F) sensor connector.

Is there poor contact in front oxygen (A/F) sensor connector? 

YES 

Repair the poor contact in front oxygen (A/F) sensor connector.

NO 

Replace the front oxygen (A/F) sensor.