DTC Troubleshooting

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.

1. Turn the ignition switch ON (II).
2. Clear the DTC with the HDS.
3. Start the engine. Hold the engine speed at 3,000 rpm without load (in neutral) until the radiator fan comes on, then let it idle.
4. Test-drive under these conditions:
- ECT SENSOR 1 above 158 °F (70 °C)
- Transmission in 3rd gear
- Drive the vehicle between 25-55 mph (40-88 km/h) for 5 minutes.
- Drive at a steady speed between 25-55 mph (40-88 km/h) for 10 minutes, then slow down with the throttle completely closed for 4 seconds.

5. Monitor the OBD STATUS for DTC P2A00 in the DTCs MENU with the HDS.

Does the screen indicate FAILED?

YES - Go to step 6.

NO - If the screen indicates PASSED, intermittent failure, the system is OK at this time. Check for poor connections or loose at the A/F sensor (Sensor 1) and the ECM. If the screen indicates EXECUTING, keep driving until a result comes on. If the screen indicates OUT OF CONDITION, Go to step 3 and recheck.

6. Turn the ignition switch OFF.
7. Replace the A/F sensor (Sensor 1).
8. Turn the ignition switch ON (II).
9. Reset the ECM with the HDS.
10. Do the ECM idle learn procedure.
11. Test-drive under these conditions:
- ECT SENSOR 1 above 15 °F (70 °C)
- Transmission in 3rd gear
- Drive first the vehicle between 25-55 mph (40-88 km/h) for 5 minutes.
- Drive at steady speed between 25-55 mph (40-88 km/h) for 10 minutes, then slow down with the throttle completely closed for 4 seconds.

12. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P2A00 indicated?

YES - Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the ECM, then Go to step 1.

NO - Go to step 13.

13. Monitor the OBD STATUS for DTC P2A00 in the DTCs MENU with the HDS.

Does the screen indicate PASSED?

YES - Troubleshooting is complete. If any other Temporary DTCs or DTCs were indicated in step 12, Go to the indicated DTCs troubleshooting.

NO - If the screen indicates FAILED, check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the ECM, then Go to step 1. If the screen indicates EXECUTING, keep driving until a result comes on. If the screen indicates OUT OF CONDITION, Go to step 11.