P2631

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 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, system is OK at this time. Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the 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 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 PCM connector terminal D11 (D10)* and body ground.

Is there continuity?

YES - Go to step 11.

NO - Repair open in the wire between the PCM (D11 (D10)*) and the A/F sensor (Sensor 1), then go to step 19.

11. Remove the jumper wire from the A/F sensor (Sensor 1) 8P connector.
12. Disconnect 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 PCM connector terminal C12 and body ground.

Is there continuity?

YES - Go to step 15.

NO - Repair open in the wire between the 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 PCM connectors C (22P) and D (17P).
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 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 PCM with the HDS.
22. Do the PCM idle learn procedure.
23. Check for Temporary DTCs or DTCs with the HDS.

Are any Temporary DTCs or DTCs indicated?

YES - If DTC P2628 and/or P2631* is indicated, check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM, then go to step 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.

NO - Troubleshooting is complete.

24. Update the PCM if it does not have the latest software, or substitute a known-good PCM.
25. Check for Temporary DTCs or DTCs with the HDS.

Are any Temporary DTCs or DTCs indicated?

YES - If DTC P2628 and/or P2631* is indicated, check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM, then go to step 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.

NO - If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM.