DTC Troubleshooting

DTC Troubleshooting: P1172, P1174

DTC P1172:

Rear A/F Sensor (Bank 1, Sensor 1) Circuit Out of Range High

DTC P1174:

Front A/F Sensor (Bank 2, Sensor 1) Circuit Out of Range High

NOTE:

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

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

2. Clear the DTC with the HDS.

3. Start the engine. Hold the engine speed at 3,000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.

4. Monitor the OBD STATUS for P1172 and/or P1174* in the DTCs MENU with the HDS.

Does the screen indicate FAILED?

YES -

Go to step 5.

NO -

If the screen indicates PASSED, 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 PCM. If the screen indicates EXECUTING, keep idling until a result comes on. If the screen indicates OUT OF CONDITION, go to step 3 and recheck.

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

6. Replace the A/F sensor (Sensor 1) A/F Sensor Replacement.

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

8. Reset the PCM with the HDS.

9. Do the PCM idle learn procedure PCM Idle Learn Procedure.

10. Start the engine. Hold the engine speed at 3,000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.

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

Is DTC P1172 and/or P1174* indicated?

YES -

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

NO -

Go to step 12.

12. Monitor the OBD STATUS for DTC P1172 and/or P1174* 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 11, 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 PCM, then go to step 1. If the screen indicates EXECUTING keep idling until a result comes on. If the screen indicates OUT OF CONDITION, go to step 10.