DTC Troubleshooting

Control System DTCs

DTC Troubleshooting: P1172

DTC P1172 : A/F Sensor (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 How To Troubleshoot The Fuel And Emissions Systems.

1. Problem verification:

Problem verification
-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 (A/T in P or N, M/T in neutral) until the radiator fan comes on, then let it idle.

-4. Monitor the OBD STATUS for DTC P1172 with the HDS.

Does the HDS indicate FAILED?
-YES- Replace A/F sensor (Sensor 1) A/F Sensor Removal and Installation, then do the repair verification.
-NO- If the HDS 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 ECM/PCM. If the HDS indicates EXECUTING, keep driving until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 1-3 and recheck.

Repair verification (OBD STATUS check):

-1. Turn the ignition switch to LOCK (0).

-2. Reconnect all connectors.

-3. Turn the ignition switch to ON (II).

-4. Reset the ECM/PCM with the HDS How To Troubleshoot The Fuel And Emissions Systems.

-5. Do the ECM/PCM idle learn procedure ECM/PCM Idle Learn Procedure.

-6. Start the engine. Hold the engine speed at 3,000 rpm without load (A/T in P or N, M/T in neutral) until the radiator fan comes on, then let it idle.

-7. Monitor the OBD STATUS for DTC P1172 in the DTCs MENU with the HDS.

Does the HDS indicate PASSED, FAILED, EXECUTING, or OUT OF CONDITION?
-PASSED- Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated, go to the indicated DTC's troubleshooting.
-FAILED- Go to step 1 and recheck.
-EXECUTING- Keep idling until a result comes on.
-OUT OF CONDITION- Meet the test condition, and check the OBD STATUS again.