DTC Troubleshooting: P2271 (63)
DTC P2271:
 Secondary HO2S (Sensor 2) Circuit Signal Stuck Rich
NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.
  1. Turn the ignition switch to ON (II).
  1. Clear the DTC with the HDS.
  1. Start the engine. Hold the engine speed at 3,000 rpm (min −1 ) without load (in neutral) until the radiator fan comes on, then let it idle.
  1. Test-drive under these conditions:
    • Engine coolant temperature (ECT SENSOR 1) above 70 °C (158 °F)
    • Vehicle speed between 88−120 km/h (55−75 mph) for 1 minute, then decelerate (with throttle fully closed). Repeat this 3 times or more
  1. Monitor the OBD STATUS for DTC P2271 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 terminals at the secondary HO2S (Sensor 2) 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.
  1. Turn the ignition switch to LOCK (0).
  1. Turn the ignition switch to ON (II).
  1. Reset the ECM with the HDS.
  1. Start the engine. Hold the engine speed at 3,000 rpm (min −1 ) without load (in neutral) until the radiator fan comes on, then let it idle.
  1. Test-drive under these conditions:
    • Engine coolant temperature (ECT SENSOR 1) above 70 °C (158 °F)
    • Vehicle speed between 88−120 km/h (55−75 mph) for 1 minute, then decelerate (with throttle fully closed). Repeat this 3 times or more
  1. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P2271 indicated?
YES -
Check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the ECM, then go to Step 1 .
NO -
Go to Step 14 .
  1. Monitor the OBD STATUS for DTC P2271 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 13 , go to the indicated DTC's troubleshooting.■
NO -
If the screen indicates FAILED, check for poor connections or loose terminals at the secondary HO2S (Sensor 2) 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 .