P2271
DTC P2271 HO2S SIGNAL STUCK RICH (BANK 1 / SENSOR 2)Component Location:
GENERAL DESCRIPTION
Rear HO2S behind the catalytic converter 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 scan tool 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 replaces necessary and go to "Verification of Vehicle Repair" procedure
NO: Go to "Terminal and Connector Inspection" procedure.
TERMINAL AND CONNECTOR INSPECTION
1. Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical Systems, and mechanical or chemical damage.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage
3. Has a problem been found?
YES: Repair 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 as follow.
- Contamination, deformation or age of HO2S(B1/S2)
2. Is the HO2S(B1/S2) normal ?
YES: Go to "Check performance of HO2S" as follows.
NO: Substitute with a known-good HO2S(B1S2) 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(B1S2) 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 rediness test have been verified as" Complete"
5. Are any DTCs present?
YES: Go to the applicable trouble shooting procedure.
NO: System is performing to specification at this time.