DTC P2271 [13B-MSP]

id0102g1827300

DTC P2271

HO2S signal stuck rich

DETECTION CONDITION

•  The PCM monitors the input voltage from the HO2S when the following conditions are met. If the input voltage is more than 0.85 V for 40 s, the PCM determines that the HO2S signal remains rich.

MONITORING CONDITIONS

―  ECT: more than 70 °C {158 °F}

―  Engine speed: more than 1,500 rpm

―  MAF amount: more than 10 g/s {1.32 lb/min}

―  Short term fuel trim: -20—20%

―  Long term fuel trim: -50—50%

―  Target A/F feedback system status: feedback control

Diagnostic support note

•  This is an intermittent monitor (A/F sensor, HO2S).

•  The MIL illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM.

•  PENDING CODE is available if the PCM detects the above malfunction condition during the first drive cycle.

•  FREEZE FRAME DATA is available.

•  The DTC is stored in the PCM memory.

POSSIBLE CAUSE

•  HO2S malfunction

•  Leakage exhaust gas

•  Fuel line pressure malfunction

•  Fuel pump unit malfunction

•  Purge solenoid valve malfunction

•  Fuel injector malfunction

•  Leakage engine coolant

•  PCM malfunction

DTC P2271	HO2S signal stuck rich
DETECTION CONDITION	• The PCM monitors the input voltage from the HO2S when the following conditions are met. If the input voltage is more than 0.85 V for 40 s, the PCM determines that the HO2S signal remains rich. MONITORING CONDITIONS ― ECT: more than 70 °C {158 °F} ― Engine speed: more than 1,500 rpm ― MAF amount: more than 10 g/s {1.32 lb/min} ― Short term fuel trim: -20—20% ― Long term fuel trim: -50—50% ― Target A/F feedback system status: feedback control Diagnostic support note • This is an intermittent monitor (A/F sensor, HO2S). • The MIL illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM. • PENDING CODE is available if the PCM detects the above malfunction condition during the first drive cycle. • FREEZE FRAME DATA is available. • The DTC is stored in the PCM memory.
POSSIBLE CAUSE	• HO2S malfunction • Leakage exhaust gas • Fuel line pressure malfunction • Fuel pump unit malfunction • Purge solenoid valve malfunction • Fuel injector malfunction • Leakage engine coolant • PCM malfunction

Diagnostic procedure

STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA AND DIAGNOSTIC MONITORING TEST RESULTS HAVE BEEN RECORDED • Have FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS (A/F sensor, HO2S related) been recorded?	Yes	Go to the next step.
1		No	Record the FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS on the repair order, then go to the next step.
2	VERIFY RELATED SERVICE INFORMATION AVAILBAILITY • Verify related Service information availability. • Is any related Service information available?	Yes	Perform repair or diagnosis according to thavailable Service information. • If the vehicle is not repaired, go to the next step.
2		No	Go to the next step.
3	VERIFY RELATED PENDING CODE OR STORED DTC • Turn the ignition switch off, then to the ON position (engine off). • Verify the related PENDING CODE or stored DTCs. • Are other DTCs present?	Yes	Go to the appropriate DTC inspection. (See DTC TABLE [13B-MSP].)
3		No	Go to the next step.
4	IDENTIFY TRIGGER DTC FOR FREEZE FRAME DATA • Is DTC P2271 on FREEZE FRAME DATA?	Yes	Go to the next step.
4		No	Go to the FREEZE FRAME DATA DTC inspection. (See DTC TABLE [13B-MSP].)
5	INSPECT HO2S • Inspect the HO2S. (See HEATED OXYGEN SENSOR (HO2S) INSPECTION [13B-MSP].) • Is there any malfunction?	Yes	Inspect the following: • Loose installation of HO2S • Exhaust gas leakage between TWC and HO2S If there is no malfunction detected, replace the HO2S. (See HEATED OXYGEN SENSOR (HO2S) REMOVAL/INSTALLATION [13B-MSP].) If there is a malfunction detected, repair or replace the malfunctioning part. Then go to Step 10.
5		No	Go to the next step.
6	INSPECT FUEL LINE PRESSURE • Perform the “FUEL LINE PRESSURE INSPECTION”. (See FUEL LINE PRESSURE INSPECTION [13B-MSP].) • Is there any malfunction?	Yes	Replace the fuel pump unit, then go to Step 10. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [13B-MSP].)
6		No	Go to the next step.
7	INSPECT PURGE SOLENOID VALVE • Inspect the purge solenoid valve. (See PURGE SOLENOID VALVE INSPECTION [13B-MSP].) • Is there any malfunction?	Yes	Replace the purge solenoid valve, then go to Step 10.
7		No	Go to the next step.
8	INSPECT FUEL INJECTOR • Inspect the fuel injector. (See FUEL INJECTOR INSPECTION [13B-MSP].) • Is there any malfunction?	Yes	Replace the fuel injector, then go to Step 10. (See FUEL INJECTOR REMOVAL/INSTALLATION [13B-MSP].)
8		No	Go to the next step.
9	INSPECT ENGINE COOLANT PASSAGE FOR ENGINE COOLANT LEAKAGE • Perform the “ENGINE COOLANT LEAKAGE INSPECTION”. (See ENGINE COOLANT LEAKAGE INSPECTION [13B-MSP].) • Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results, then go to the next step.
9		No	Go to the next step.
10	VERIFY TROUBLESHOOTING OF DTC P2271 COMPLETED • Make sure to reconnect all disconnected connectors. • Clear the DTC from the PCM memory using the M-MDS. • Perform the DRIVE MODE 03. (See OBD DRIVE MODE [13B-MSP].) • Is the PENDING CODE same as DTC present?	Yes	Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION [13B-MSP].)
10		No	Go to the next step.
11	VERIFY AFTER REPAIR PROCEDURE • Perform the “AFTER REPAIR PROCEDURE”. (See AFTER REPAIR PROCEDURE [13B-MSP].) • Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [13B-MSP].)
11		No	DTC troubleshooting completed.