Diagnosis & Repair Procedure
- Perform DTC CONFIRMATION TEST . If DTC P0131 or P0132 is set, go to next step. If DTC P0131 or P0132 is not set, problem is intermittent. System is okay at this time. See TROUBLE SHOOTING - NO CODES article.
- Check for DTCs. See RETRIEVING DIAGNOSTIC TROUBLE CODES under SELF-DIAGNOSTIC SYSTEM. If any other DTC is also set, repair those DTCs first. If no other DTCs are set, go to next step.
- Connect scan tool. Start engine and allow it to reach normal operating temperature. Increase engine speed to 2000 RPM for at least one minute. Allow engine to return to idle. Increase engine speed 5-6 times repeatedly while monitoring HO2S No. 1 parameter on scan tool. If parameter reading does not vary from less than 0.3 volt to more than 0.6 volt, go to next step. If parameter reading varies from less than 0.3 volt to more than 0.6 volt, problem is intermittent. System is okay at this time. See TROUBLE SHOOTING - NO CODES article.
- Turn ignition off. Disconnect HO2S No. 1 connector and PCM 16-pin connector C22. Check for poor terminal contact at HO2S No. 1 connector and PCM 16-pin connector C22. If poor terminal contact is found, repair as necessary and go to DTC CONFIRMATION TEST . If connections are okay, check for open or short in Red wire between HO2S No. 1 harness connector terminal No. 2 and PCM 16-pin harness connector C22 terminal No. 13. See Figure. Also check for open or short in Light Green/Black wire between HO2S No. 1 harness connector terminal No. 1 and PCM 16-pin harness connector C22 terminal No. 9. See WIRING DIAGRAMS article. Repair wires as necessary. If wires are okay, replace HO2S No. 1 and go to DTC CONFIRMATION TEST .