DTC Troubleshooting

DTC P2628: Rear A/F Sensor (Bank 1, Sensor 1) LABEL Circuit High Voltage

DTC P2631: Front A/F Sensor (Bank 2, Sensor 1) LABEL Circuit High Voltage

NOTE:
- Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.
- Information marked with an asterisk (*) applies to the front bank (Bank 2).

1. Turn the ignition switch ON (II).
2. Clear the DTC with the HDS.
3. Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or neutral) until the radiator fan comes on, then let it idle for 2 minutes.
4. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P2628 and/or P2631* indicated?

YES - Go to step 5.

NO - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the ECM/PCM.

5. Turn the ignition switch OFF.
6. Jump the SCS line with the HDS.
7. Disconnect the A/F sensor (Sensor 1) 8P connector.
8. Disconnect ECM/PCM connector D (17P).




9. Connect A/F sensor (Sensor 1) 8P connector terminal No. 4 to body ground with a jumper wire.




10. Check for continuity between ECM/PCM connector terminal D11 (D10)* and body ground.

Is there continuity?

YES - Go to step 11.

NO - Repair open in the wire between the ECM/PCM (D11 (B10)*) and the A/F sensor (Sensor 1), then go to step 15.

11. Remove the jumper wire from the A/F sensor (Sensor 1) 8P connector.
12. Disconnect ECM/PCM connector C (22P).




13. Connect A/F sensor (Sensor 1) 8P connector terminal No. 3 to body ground with a jumper wire.




14. Check for continuity between ECM/PCM connector terminal C12 and body ground.

Is there continuity?

YES - Go to step 15.

NO - Repair open in the wire between the ECM/PCM (C12) and the A/F sensor (Sensor 1), then go to step 19.

15. Remove the jumper wire from the A/F sensor (Sensor 1) 8P connector, then reconnect ECM/PCM connectors D (17P) and C (22P).
16. Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or neutral) until the radiator fan comes on, then let it idle 2 minutes.




17. Measure voltage between ECM/PCM connector terminals D11 (D10)* and C12.

Is there about 5 V?

YES - Go to step 18.

NO - Go to step 24.

18. Replace the A/F sensor (Sensor 1).
19. Reconnect all connectors.
20. Turn the ignition switch ON (II).
21. Reset the ECM/PCM with the HDS.
22. Do the ECM/PCM idle learn procedure.
23. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P2628 and/or P263V indicated?

YES - Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the ECM/PCM, then go to step 1.

NO - Troubleshooting is complete. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTCs troubleshooting.

24. Turn the ignition switch OFF.
25. Reconnect all connectors.
26. Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM.
27. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P2628 and/or P2631* indicated?

YES - Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the ECM/PCM. If the ECM/PCM was updated, substitute a known-good ECM/PCM, then recheck. If the ECM/PCM was substituted, go to step 1.

NO - If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTCs troubleshooting.