P2628

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

NOTE: 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 with no 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, system is OK at this time. Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and at 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 A (73P).




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 terminals A55 (A52)* and body ground.

Is there continuity?

YES - Go to step 11.

NO - Repair open in the wire between the PCM (A56 (A52)*) and the A/F sensor (Sensor 1), then go to step 17.

11. Remove the jumper wire from the A/F sensor connector.




12. Check for continuity between A/F sensor (Sensor 1) 8P connector terminal No.3 and body ground.

Is there continuity?

YES - Go to step 13.

NO - Repair open in the wire between the A/F sensor (Sensor 1) and body ground, then go to step 17.

13. Reconnect the PCM connector A (73P).
14. Start the engine. Hold the engine speed at 3,000 rpm with no load (in Park or neutral) until the radiator fan comes on, then let it idle.




15. Measure voltage between A/F sensor (Sensor 1) 8P connector terminal No.4 and body ground.

Is there about 5 V?

YES - Go to step 16.

NO - Go to step 23.

16. Replace the A/F sensor (Sensor 1).
17. Reconnect PCM connector A (73P) and the A/F sensor (Sensor 1) 8P connector.
18. Turn the ignition switch ON (II).
19. Reset the PCM with the HDS.
20. Do the PCM idle learn procedure.
21. Start the engine. Hold the engine speed at 3,000 rpm with no load (in Park or neutral) until the radiator fan comes on, then let it idle for 2 minutes.
22. 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.

23. Update the PCM if it does not have the latest software, or substitute a known-good PCM.
24. Start the engine. Hold the engine speed at 3,000 rpm with no load (in Park or neutral) until the radiator fan comes on, then let it idle for 2 minutes.
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.