DTC Troubleshooting

Control System DTCs

DTC Troubleshooting: P2A00

DTC P2A00 : A/F Sensor (Sensor 1) Circuit Range/Performance Problem

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 3rd
* Vehicle speed between 25-55 mph (40-90 km/h) for 5 minutes
* Drive at a steady speed between 55-75 mph (88- 120 km/h) for 10 seconds, then decelerate (with throttle fully closed) for 4 seconds or more

-5. Monitor the OBD STATUS for DTC P2A00 with the HDS.

Does the HDS indicate FAILED?
-YES- Replace the 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 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. Test-drive under these conditions:
* Engine coolant temperature (ECT SENSOR 1) above 158 °F (70 °C)
* A/T in D, M/T in 3rd
* Vehicle speed between 25-55 mph (40-90 km/h) for 5 minutes
* Drive at a steady speed between 55-75 mph (88- 120 km/h) for 10 seconds, then decelerate (with throttle fully closed) for 4 seconds or more

-5. Monitor the OBD STATUS for DTC P2A00 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 driving until a result comes on.
-OUT OF CONDITION- Meet the test condition, and check the OBD STATUS again.