P0133

DTC P0133

Circuit Description

Heated oxygen sensors (HO2S) are used for fuel control and post catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content in the exhaust stream. The HO2S must reach operating temperature to provide an accurate voltage signal. Heating elements inside the HO2S minimize the time required for the sensors to reach operating temperature. The powertrain control module (PCM) supplies the HO2S with a reference, or bias, voltage of about 450 mV. When the engine is first started the PCM operates in open loop, ignoring the HO2S voltage signal. Once the HO2S reaches operating temperatures and Closed Loop is achieved, the HO2S generates a voltage within a range of 0-1,000 mV that fluctuates above and below bias voltage. High HO2S voltage indicates a rich exhaust stream. Low HO2S voltage indicates a lean exhaust stream.

This diagnostic will only run once per ignition cycle. The PCM monitors the rich-to-lean and lean-to-rich transition time. A transition is defined as the HO2S voltage changes from above 650 mV to below 450 mV or from below 450 mV to above 650 mV. If the PCM detects that the transition time is too long, DTC P0133 will set.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0133 HO2S Slow Response Sensor 1

Conditions for Running the DTC

* DTCs P0030, P0068, P0069, P0097, P0098, P0101, P0102, P0103, P0106, P0107, P0108, P0117, P0118, P0120, P0121, P0125, P0128, P0131, P0132, P0134, P0201, P0202, P0203, P0204, P0220, P0300, P0442, P0443, P0446, P0449, P0452, P0453, P0461, P0496, P1133, P1516, P1681, P2101, P2135, or P2176 are not set.
* The Engine Coolant Temperature (ECT) Sensor parameter is more than 70°C (158°F).
* The Ignition 1 Signal parameter is between 11-18 volts.
* The Fuel Level Sensor parameter is more than 10 percent.
* The Engine Run Time parameter is more than 200 seconds.
* The Engine Speed parameter is between 1,000-3,500 RPM.
* The Manifold Absolute Pressure (MAP) Sensor parameter is more than 30 kPa.
* The Mass Airflow (MAF) Sensor parameter is between 15-50 g/s.
* The Loop Status parameter is closed.
* The Throttle Position (TP) Indicated Angle parameter is more than 5 percent.
* The catalyst test is not active.
* Traction control is not active.
* No fuel injectors are disabled.
* The transmission is not in Park, Reverse, or Neutral.
* DTC P0133 runs once per drive cycle when the above conditions are met for 2 seconds.

Conditions for Setting the DTC

* The PCM detects that the HO2S 1 rich-to-lean or lean-to-rich average response time is more than 0.1 second.
* DTC P0133 sets within 60 seconds when the above condition is met.

Action Taken When the DTC Sets

* The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
* The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

Conditions for Clearing the MIL/DTC

* The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
* A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
* A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
* Clear the MIL and the DTC with a scan tool.

Test Description

Step 1 - Step 9:

Step 10 - Step 13:

The number below refers to the step number on the diagnostic table.
2. If the voltage is varying above and below the specified value, the condition is not present.