DTC P2271
Precautions: General safety (00)
DTC Detecting Condition and Trouble Area
| DTC detecting condition | Trouble area |
|---|---|
|
P2271: O2 Sensor Signal Biased / Stuck Rich (Sensor 2) HO2S-2 signal stays in rich state for 5 sec. after warning up even if vehicle is under fuel cut condition. (3 D/C detection logic) |
•HO2S-2 and/or its circuit
•Exhaust system •Air intake system •Fuel system •Engine compression •Ignition system •Emission control system •ECM |
Circuit Diagram
| [A]: | ECM connector (View: [a]) | B1: | HO2S-2 heater power supply circuit | 2. | HO2S-2 |
| A1: | HO2S-1 heater power supply circuit | B2: | HO2S-2 signal circuit | 3. | ECM |
| A2: | HO2S-1 signal circuit | B3: | HO2S-2 ground circuit | 4. | Shield wire |
| A3: | HO2S-1 ground circuit | B4: | HO2S-2 heater drive circuit | ||
| A4: | HO2S-1 heater drive circuit | 1. | HO2S-1 |
DTC Confirmation Procedure
WARNING:
If you do not select a suitable route and take proper precautions when performing a road test, an accident can occur.
•Select a level road with no traffic to minimize the risk of accident.
•Perform the test extremely carefully.
•Perform the road test with 2 persons, a driver and a tester.
•Perform the test extremely carefully.
•Perform the road test with 2 persons, a driver and a tester.
NOTE:
Check that the following DTCs are not detected in this “DTC Confirmation Procedure”.
•HO2S-2 heater (P0036, P0037 and P0038)
•HO2S-2 (P0137, P0138 and P0140)
•Fuel trim system (P0171 and P0172)
•Cylinder misfire detected (P0300)
•CKP sensor (P0335)
•CMP sensor (P0340)
•EVAP canister purge valve (P0443, P0458 and P0459)
•System voltage (P0560, P0562 and P0563)
•HO2S-2 (P0137, P0138 and P0140)
•Fuel trim system (P0171 and P0172)
•Cylinder misfire detected (P0300)
•CKP sensor (P0335)
•CMP sensor (P0340)
•EVAP canister purge valve (P0443, P0458 and P0459)
•System voltage (P0560, P0562 and P0563)
1)Warm up engine to normal operating temperature.
2)Drive vehicle at 50 to 80 km/h (31 to 50 mile/h) constantly for 5 min. or more at 5th gear (M/T model) or D range (A/T model). (Keep throttle valve opening constant in this step.)
3)Release accelerator pedal, and keep vehicle coasting for 10 sec. in engine braking condition. (fuel cut)
4)Stop vehicle, and run engine at idle speed for 5 min.
5)Check whether O2 sensor readiness / monitoring test has completed or not using scan tool. If O2 sensor readiness / monitoring test has not completed, check vehicle conditions (environmental) and repeat Step 2) – 5).
DTC Troubleshooting
| Step | Action | Yes | No |
|---|---|---|---|
| 1 |
Was “Engine and Emission Control System Check” performed?
|
Go to Step 2.
|
|
| 2 |
DTC check
Is there any DTC(s) other than P2271?
|
Go to troubleshooting for applicable DTC.
|
Go to Step 3.
|
| 3 |
Exhaust system and air intake system check
1)Check exhaust system and air intake system for clogging or leakage.
Is check result OK?
|
Go to Step 4.
|
Repair or replace defective part.
|
| 4 |
HO2S-2 signal and ground circuit check
1)Check the following point.
Is check result OK?
|
Go to Step 5.
|
Repair or replace defective wire harness.
|
| 5 |
Engine mechanical system check
1)Check the following points related to engine mechanical system.
•Engine compression:
 •Fuel pressure: •Spark plug: Is check result OK?
|
Go to Step 6.
|
Repair or replace defective parts.
|
| 6 |
Fuel system and emission control system check
1)Check the following points related to fuel system and emission control system.
•EVAP canister purge valve:
•MAP sensor: •PCV valve: •Fuel injector: •Fuel injector circuit: Is check result OK?
|
Go to Step 7.
|
Repair or replace defective parts.
|
| 7 |
Recheck DTC
1)Replace HO2S-2.
2)Perform “DTC Confirmation Procedure” and check DTC.
Is DTC P2271 still detected?
|
Replace ECM and recheck DTC.
|
End.
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