## DTC Troubleshooting: P2270 (63), P2271 (63)

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

NOTE: If some of the DTCs listed below are stored at the same time as DTC P2270 and/or P2271, troubleshoot those DTCs first, then recheck for P2270 and/or P2271
P0137, P0138, P0140: Secondary HO2S (Sensor 2)
P0141: Secondary HO2S (Sensor 2) heater

1. | Check for exhaust leak at the exhaust system. Is there exhaust leak? YES - Repair the exhaust leak, then go to 4. NO - Go to 2.

2. | Turn the ignition switch OFF.

3. | Replace the secondary HO2S (Sensor 2).

4. | Start the engine. Hold the engine speed at 3,000 rpm (min-1) with no load (in neutral) until the radiator fan comes on, then let it idle.

5. | Check for Temporary DTCs or DTCs in the DTCs MENU with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P2270 and/or P2271 is indicated, check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the ECM, then go to 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC troubleshooting. NO - Troubleshooting is complete.n