DTC Advanced Diagnostics: P0133 (3.0L Engine)
DTC P0133: Rear Air/Fuel Ratio (A/F) Sensor (Bank 1, Sensor 1) Malfunction/Slow Response
General Description
The powertrain control module (PCM) forcibly sets the target of the air/fuel ratio to a certain width to monitor the responsiveness of the rear air/fuel ratio (A/F) sensor (bank 1, sensor 1). If the amplitude output by the rear A/F sensor (bank 1, sensor 1) at that time is narrow, the PCM detects a malfunction and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Once per driving cycle |
| Sequence | None |
| Duration | 5 seconds or more |
| DTC Type | Two drive cycles, MIL on |
Enable Conditions
| Condition | Minimum | Maximum |
|---|---|---|
| Engine coolant temperature [ECT Sensor 1] | 140 deg.F (60 deg.C) | - |
| Engine speed [Engine Speed] | 1, 200 rpm | 3, 800 rpm |
| Mass airflow [MAF Sensor] | 20 g/s (0.71 oz/s) | 40 g/s (1.41 oz/s) |
| Fuel feedback | Closed loop at stoichiometric | |
[ ]: HDS Parameter
Malfunction Threshold
The amplitude output by the rear A/F sensor (bank 1, sensor 1) is less than the value shown in the table for at least 5 seconds. The malfunction threshold value changes depending on the mass airflow (MAF) sensor value.
| MAF sensor value [MAF Sensor] | Malfunction threshold value |
|---|---|
| 20 g/s (0.71 oz/s) | Less than 0.010 |
| 25 g/s (0.89 oz/s) | Less than 0.014 |
| 30 g/s (1.06 oz/s) | Less than 0.017 |
| 35 g/s (1.24 oz/s) | Less than 0.020 |
| 40 g/s (1.41 oz/s) | Less than 0.023 |
Possible Cause
- Rear A/F sensor (bank 1, sensor 1) failure
Confirmation Procedure
Operating Condition
- Start the engine. Hold the engine speed [Engine Speed] at 3, 000 rpm without load (in P or N) until the radiator fan comes on.
- Drive the vehicle at a steady speed of 25 mph (40 km/h) or less, for at least 5 minutes.
- Drive immediately at a steady speed of 36 mph (57 km/h) or more and engine speed [Engine Speed] between 1, 200 - 3, 800 rpm for at least 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, the freeze data, and the on-board snapshot 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, the freeze data, and the on-board snapshot can be cleared with the scan tool clear command.