DTC P0133 [LF]: Notes

DTC P0133 (LF) DETECTION CONDITION AND POSSIBLE CAUSE

DTC P0133	A/F sensor circuit problem
DETECTION CONDITION	The PCM monitors the peak differential value of oxygen sensor signal after A/F fluctuation being provided when the following conditions are met. If the peak differential value is lower than the threshold value. The PCM determines that A/F sensor circuit is slow. MONITORING CONDITION PCM Adaptive Memory Production, EGR System, A/F Sensor Heater, HO2S Heater, A/F Sensor, HO2S, and TWC Repair Verification Drive Mode Following conditions are met: A/F sensor heater monitor is completed. Fuel system loop status is closed loop fuel control. Engine speed: 1,750-3,500 RPM Charging efficiency: 25-63% (at engine speed: 2,500 RPM ) Engine coolant temperature: above 70°C {158°F} 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 (Mode 2/Mode 12) is available. The DTC is stored in the PCM memory.
POSSIBLE CAUSE	A/F sensor malfunction A/F sensor connector or terminals malfunction A/F sensor looseness Exhaust system leakage Fuel supply system malfunction or improper fuel line pressure Fuel leakage in fuel line between fuel distribution pipe and fuel pump Clogged or restricted fuel filter (built-in fuel pump unit) Pressure regulator (built-in fuel pump unit) malfunction Fuel pump malfunction Purge system malfunction Purge solenoid valve malfunction Improper connection purge solenoid hose Engine malfunction (Engine coolant leakage) Engine coolant leakage to combustion chamber Insufficient compression A/F sensor deterioration PCM malfunction

DTC P0133

A/F sensor circuit problem

DETECTION CONDITION

The PCM monitors the peak differential value of oxygen sensor signal after A/F fluctuation being provided when the following conditions are met. If the peak differential value is lower than the threshold value.
The PCM determines that A/F sensor circuit is slow.
MONITORING CONDITION
- PCM Adaptive Memory Production, EGR System, A/F Sensor Heater, HO2S Heater, A/F Sensor, HO2S, and TWC Repair Verification Drive Mode
- Following conditions are met:
  - A/F sensor heater monitor is completed.
  - Fuel system loop status is closed loop fuel control.
- Engine speed: 1,750-3,500 RPM
- Charging efficiency: 25-63% (at engine speed: 2,500 RPM )
- Engine coolant temperature: above 70°C {158°F}

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 (Mode 2/Mode 12) is available.
The DTC is stored in the PCM memory.

POSSIBLE CAUSE

A/F sensor malfunction
- A/F sensor connector or terminals malfunction
- A/F sensor looseness
- Exhaust system leakage
Fuel supply system malfunction or improper fuel line pressure
- Fuel leakage in fuel line between fuel distribution pipe and fuel pump
- Clogged or restricted fuel filter (built-in fuel pump unit)
- Pressure regulator (built-in fuel pump unit) malfunction
- Fuel pump malfunction
Purge system malfunction
- Purge solenoid valve malfunction
- Improper connection purge solenoid hose
Engine malfunction (Engine coolant leakage)
- Engine coolant leakage to combustion chamber
- Insufficient compression
A/F sensor deterioration
PCM malfunction