DTC Troubleshooting

DTC P2238: A/F Sensor (Sensor 1) AFS+ Circuit Low Voltage

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.

1. Turn the ignition switch ON (II).
2. Clear the DTC with the HDS.
3. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P2238 indicated?

YES - Go to step 4.

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 ECM/PCM.

4. Turn the ignition switch OFF.
5. Jump the SCS line with the HDS.
6. Disconnect the A/F sensor (Sensor 1) 4P connector.
7. Disconnect ECM/PCM connector A (31P).




8. Check for continuity between ECM/PCM connector terminal A31 and body ground.

Is there continuity?

YES - Repair short in the wire between the ECM/PCM (A31) and the A/F sensor (Sensor 1), then go to step 10.

NO - Go to step 9.

9. Replace the A/F sensor (Sensor 1).
10. Reconnect all connectors.
11. Turn the ignition switch ON (II).
12. Reset the ECM/PCM with the HDS.
13. Do the ECM/PCM idle learn procedure.
14. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P2238 indicated?

YES - Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the ECM/PCM. If the connector and terminal fits are OK, go to step 16.

NO - If Temporary DTC or DTC P2238 is not indicated, or if any other Temporary DTCs or DTCs are indicated, go to step 15.

15. Monitor the OBD STATUS for DTC P2238 in the DTCs MENU with the HDS.

Does the screen indicate PASSED?

YES - If there was no Temporary DTCs or DTCs indicated on step 14, troubleshooting is complete. If any other Temporary DTCs or DTCs was indicated on step 14, go to the indicated DTC's troubleshooting.

NO - If the screen indicates FAILED, check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the ECM/PCM, then go to step 1. If the screen indicates NOT COMPLETED, go to step 13 and recheck.

16. Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM.
17. Start the engine.
18. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P2238 indicated?

YES - If the ECM/PCM was updated, substitute a known-good ECM/PCM, then go to step 17. If the ECM/PCM was substituted, go to step 1.

NO - If Temporary DTC or DTC P2238 is not indicated, or if any other Temporary DTCs or DTCs are indicated, go to step 19.

19. Monitor the OBD STATUS for DTC P2238 in the DTCs MENU with the HDS.

Does the screen indicate PASSED?

YES - 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 was indicated on step 18, go to the indicated DTC's troubleshooting.

NO - If the screen indicates FAILED, go to step 1. If the ECM/PCM was updated, substitute a known-good ECM/PCM, then go to step 17. If the ECM/PCM was substituted, go to step 1. If the screen indicates NOT COMPLETED, let the engine idle until a result comes on.