Advanced Diagnostics

Advanced Diagnostics - DTC P0133: Air/Fuel Ratio (A/F) Sensor (Sensor 1) Malfunction/Slow Response






General Description
The electronic throttle control system controls the throttle valve opening. The system includes the throttle actuator, the throttle valve, throttle position (TP) sensors A and B, the electronic throttle control system (ETCS) control relay, the accelerator pedal position (APP) sensor, and the powertrain control module (PCM). TP sensor A is a semiconductor type, and it is attached to the throttle body and shaft to determine throttle valve position. The throttle valve position signal from TP sensor A is transmitted to the PCM for target position feedback control. If the signal from TP sensor A is a fixed value for a set time, the PCM detects a TP sensor A malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type, OBD Status






Enable Conditions






Malfunction Threshold
The total A/F sensor (sensor 1) output value is 26 or less in 4.5 seconds.

Driving Pattern






1. Start the engine. Hold the engine speed at 3,000 rpm without load (in P or N) until the radiator fan comes on.
2. Drive the vehicle at a steady speed of 25 mph (40 km/h) or less, for at least 5 minutes.
3. Drive immediately at a steady speed between 26 - 81 mph (41 - 130 km/h) for at least 4.5 seconds.

- Drive the vehicle in this manner only if the traffic regulations and ambient conditions allow.

Diagnosis Details

Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on and a Confirmed DTC and the freeze data are stored.

Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the battery.