DTC P2271: Notes

DTC P2271 DETECTION CONDITION AND POSSIBLE CAUSES

DTC P2271	Middle HO2S signal stuck rich
DETECTION CONDITION	The PCM monitors the middle HO2S input voltage when the following conditions are met. If the subtracted input voltage from the target voltage (calculated by PCM) is 0.85 V or more for 25 s , or is above 0.3 V , the PCM determines that the front HO2S signal remains rich. MONITORING CONDITION 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: -15 - 15% Fuel injection system status: feedback control Diagnostic support note This is a intermittent monitor (HO2S). MIL illuminates if PCM detects above malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for the same malfunction has been stored in PCM. PENDING CODE is available if PCM detects the above malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in the PCM memory.
POSSIBLE CAUSE	Leakage exhaust gas Middle HO2S malfunction Front HO2S malfunction Front HO2S heater malfunction Middle HO2S heater malfunction Fuel pump control malfunction Fuel pressure malfunction Fuel injector malfunction Leakage exhaust gas Leakage engine coolant Purge solenoid valve malfunction Purge solenoid valve hoses improper connection Restriction in intake-air system Insufficient compression Engine oil malfunction Increased oil pressure Metering oil pump malfunction Metering oil pump control malfunction Engine malfunction PCM malfunction

DTC P2271

Middle HO2S signal stuck rich

DETECTION CONDITION

The PCM monitors the middle HO2S input voltage when the following conditions are met. If the subtracted input voltage from the target voltage (calculated by PCM) is 0.85 V or more for 25 s , or is above 0.3 V , the PCM determines that the front HO2S signal remains rich.

MONITORING CONDITION

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: -15 - 15%
Fuel injection system status: feedback control

Diagnostic support note

This is a intermittent monitor (HO2S).
MIL illuminates if PCM detects above malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for the same malfunction has been stored in PCM.
PENDING CODE is available if PCM detects the above malfunction condition during first drive cycle.
FREEZE FRAME DATA is available.
DTC is stored in the PCM memory.

POSSIBLE CAUSE

Leakage exhaust gas
Middle HO2S malfunction
Front HO2S malfunction
Front HO2S heater malfunction
Middle HO2S heater malfunction
Fuel pump control malfunction
Fuel pressure malfunction
Fuel injector malfunction
Leakage exhaust gas
Leakage engine coolant
Purge solenoid valve malfunction
Purge solenoid valve hoses improper connection
Restriction in intake-air system
Insufficient compression
- Engine oil malfunction
- Increased oil pressure
- Metering oil pump malfunction
- Metering oil pump control malfunction
- Engine malfunction
PCM malfunction