DTC Troubleshooting

DTC Troubleshooting: P2238

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

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

1. Turn the ignition switch to ON (II).

2. Clear the DTC with the HDS.

3. Check for Pending or Confirmed DTCs with the HDS.

Is DTC P2238 indicated?
YES - Go to step 4.

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.


4. Turn the ignition switch to LOCK (0).

5. Jump the SCS line with the HDS.

6. Remove the cowl cover Service and Repair and the under-cowl panel. Service and Repair

7. Disconnect the A/F sensor (Sensor 1) 4P connector.

8. Disconnect ECM/PCM connector C (49P).

9. Check for continuity between ECM/PCM connector terminal C29 and body ground.

Is there continuity?
YES - Repair short in the wire between the ECM/PCM (C29) and the A/F sensor (Sensor 1), then go to step 11.

NO - Go to step 10.






10. Reconnect ECM/PCM connector C (49P).

11. Turn the ignition switch to ON (II).

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

Is the voltage about 2.2 V?
YES - Replace the A/F sensor (Sensor 1). A/F Sensor Replacement

NO - Go to step 19.






13. Reconnect all connectors.

14. Turn the ignition switch to ON (II).

15. Reset the ECM/PCM with the HDS.

16. Do the ECM/PCM idle learn procedure. ECM/PCM Idle Learn Procedure

17. Check for Pending or Confirmed 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, then go to step 1. If the connections and the terminals are OK, go to step 19.

NO - Go to step 18.


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

Does the screen indicate PASSED?
YES - Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 17, 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 15.


19. Update the ECM/PCM if it does not have the latest software, ECM/PCM Update or substitute a known-good ECM/PCM. Initial Inspection and Diagnostic Overview

20. Start the engine, and let it idle.

21. Check for Pending or Confirmed DTCs with the HDS.

Is DTC P2238 indicated?
YES - If the ECM/PCM was updated, substitute a known-good ECM/PCM, Initial Inspection and Diagnostic Overview then go to step 20. If the ECM/PCM was substituted, go to step 1.

NO - Go to step 22.


22. 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. Service and Repair If any other Pending or Confirmed DTCs were indicated in step 21, 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, Initial Inspection and Diagnostic Overview then go to step 20. If the ECM/PCM was substituted, go to step 1. If the screen indicates NOT COMPLETED, keep idling until a result come on.