DTC P2271 O2 Sensor Signal Biased/Stuck Rich Bank 1 Sensor 2: Notes
DTC detecting condition:
Detected when two consecutive driving cycles with fault occur.
CAUTION:
- After servicing or replacing faulty parts, perform Clear Memory Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>Clear Memory Mode . and Inspection Mode Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>Inspection Mode .
- Use the check board when measuring the ECM terminal voltage and resistance.
Wiring diagram:
Engine Electrical System Ref. to WIRING SYSTEM>Engine Electrical System>WIRING DIAGRAM .
- CHECK REAR OXYGEN SENSOR CONNECTOR.
Has water entered the connector?
- Yes : Completely remove any water inside.
- No : Go to 2.
- CHECK HARNESS BETWEEN ECM AND REAR OXYGEN SENSOR CONNECTOR.
- Turn the ignition switch to OFF.
- Disconnect the connector from the rear oxygen sensor connector.
- Disconnect the connector from ECM.
- Measure the resistance of harness between ECM connector and rear oxygen sensor connector.
Connector & terminal
(E158) No. 42 - (E25) No. 3:
(E158) No. 16 - (E25) No. 4:
Is the resistance less than 1 Ω?
- Yes : Go to 3.
- No : Repair the open circuit of harness between ECM connector and rear oxygen sensor connector.
- CHECK HARNESS BETWEEN ECM AND REAR OXYGEN SENSOR CONNECTOR.
Measure the resistance between the ECM connector and engine ground.
Connector & terminal
(E158) No. 42 - Engine ground:
Is the resistance 1 MΩ or more?
- Yes : Go to 4.
- No : Repair the short circuit to ground in harness between ECM connector and rear oxygen sensor connector.
- CHECK EXHAUST SYSTEM.
Check exhaust system parts.
NOTE: Check the following items.- Looseness and improper fitting of exhaust system parts
- Damage (crack, hole etc.) of parts
- Damage (crack, hole etc.) between front oxygen (A/F) sensor and rear oxygen sensor
Is there any fault in exhaust system?
- Yes : Repair or replace faulty parts.
- No : Replace the rear oxygen sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DOTC)>Rear Oxygen Sensor .