P2271

DTC P2271 O2 SENSOR SIGNAL STUCK RICH (BANK 1 / 2 SENSOR 1)

Component Location:

GENERAL DESCRIPTION
Rear HO2S behind the catalytic convertor checks if purifying process performs well. purifying process is already done, the oxygen density of exhaust gas through catalytic converter is in the specified value.

DTC DESCRIPTION
Checking output signals from HO2S under detecting condition, if an output signal within the detecting condition lasts continuously, PCM sets P2271. MIL (Malfunction Indication Lamp) turns on when the malfunction lasts till consecutive 2 driving cycle.

DTC Detecting Condition:

Schematic Diagram:

MONITOR SCANTOOL DATA
1. Connect scantool to DLC (Data Link Connector)
2. Warm up the engine to normal operating temperature.
3. Monitor "HO2S (B1S2)" parameter on scantool

Specification : 0.1 - 0.9 V

4. Does the "HO2S (B1S2)" parameter operates correctly?

YES - Fault is intermittent caused by poor contact in Sensor's and/or PCM's connector or was repaired and PCM memory was not cleared. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.

NO - Go to "Component Inspection" procedure.

COMPONENT INSPECTION
1. Visual Inspection
1. Visually check HO2S.
- Contamination, deformation or age of HO2S (B1/S2)

2. Is the HO2S (B1/S2) normal?

YES - Go to "Check performance of HO2S".

NO - Substitute with a known-good HO2S (B1 S2) and check for proper operation. If the problem is corrected, replace HO2S (B1S2) and then go to "Verification of Vehicle Repair" procedure.




2. Check performance of HO2S
1. Connect scantool to DLC (Data Link Connector)
2. Warm up the engine to normal operating temperature.
3. Monitor signal waveform of HO2S with scantool.

Specification : 0.1 - 0.9 V.

4. Is the HO2S (B1S2) working properly?

YES - Substitute with a known-good PCM and check for proper operation. If the problem is corrected, replace PCM and then go to "Verification of Vehicle Repair" procedure.

NOTE: There is a memory reset function on scantool that can erase optional parts automatically detected and memorized by PCM.

NO - Substitute with a known-good HO2S (B182) and check for proper operation. If the problem is corrected, replace HO2S (B1S2) and then go to "Verification of Vehicle Repair" procedure.

VERIFICATION OF VEHICLE REPAIR
After a repair, it is essential to verify that the fault has been corrected.
1. Monitor and record the Freeze Frame Data for the Diagnostic Trouble Code (DTC) which has been diagnosed.
2. Using a Scantool, Clear the DTCs.
3. Operate the vehicle within conditions noted in the freeze frame data or enable conditions.
4. Monitor that all readiness test have been verified as "Complete".
5. Are any DTCs present?

YES - Go to the applicable troubleshooting procedure.

NO - System is performing to specification at this time.