DTC Troubleshooting

Control System DTCs

DTC Troubleshooting: P2270

DTC P2270 : Secondary HO2S (Sensor 2) Circuit Signal Stuck Lean

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. Test-drive under these conditions:
* Engine coolant temperature (ECT SENSOR 1) above 158 °F (70 °C)
* A/T in D, M/T in 4th
* Engine speed between 1,500-3,000 rpm
* Drive 30 seconds or more

-5. Monitor the OBD STATUS for DTC P2270 with the HDS.

Does the HDS indicate FAILED?
-YES- Replace the secondary HO2S (Sensor 2) Secondary HO2S 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 secondary HO2S (Sensor 2) and the ECM/PCM. If the HDS indicates NOT COMPLETED, go to step 1-3 and recheck.

Repair verification (OBD STATUS check):

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

-2. Reset the ECM/PCM with the HDS How To Troubleshoot The Fuel And Emissions Systems.

-3. Do the ECM/PCM idle learn procedure ECM/PCM Idle Learn Procedure.

-4. 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.

-5. Test-drive under these conditions:
* Engine coolant temperature (ECT SENSOR 1) above 158 °F (70 °C)
* A/T in D, M/T in 4th
* Engine speed between 1,500-3,000 rpm
* Drive 30 seconds or more

-6. Monitor the OBD STATUS for DTC P2270 in the DTCs MENU with the HDS.

Does the HDS indicate PASSED, FAILED, or NOT COMPLETED?
-PASSED- Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated, go to indicated DTC's troubleshooting.
-FAILED- Go to step 1 and recheck.
-NOT COMPLETED- Meet the test condition, and check the OBD STATUS again.