P1133

CIRCUIT DESCRIPTION
The Powertrain Control Module (PCM) monitors the Heated Oxygen Sensor (HO2S) activity for 100 seconds. During this test period the PCM counts the number of times that the HO2S voltage crosses the rich to lean and lean to rich thresholds. A lean to rich switch is determined when the HO2S voltage changes from less than 300 mV to greater than 600 mV. A rich to lean switch is determined when the HO2S voltage changes from more than 600 mV to less than 300 mV. If the PCM determines that the HO2S did not switch enough times, DTC P1133 will set.

CONDITIONS FOR RUNNING THE DTC
^ DTCs P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0125, P0128, P0201, P0202, P0203, P0204, P0205, P0206, P0300, P0410, P0440, P0442, P0443, P0446, P0449, P1441 are not set.
^ Mass Air Flow (MAF) is between 8 g/s and 35 g/s.
^ Engine Coolant Temperature (ECT) is greater than 70°C (167°F).
^ Engine run time is greater than 60 seconds.
^ Engine speed is between 1000 RPM and 3000 RPM.
^ The engine is running in closed loop.

CONDITIONS FOR SETTING THE DTC
^ The above conditions are present for a 100 second monitoring period.
^ The PCM monitors fewer than 40 rich to lean and 40 lean to rich switches for HO2S 1.

ACTION TAKEN WHEN THE DTC SETS
^ First failure:
- The MIL is not turned ON.
- A DTC is stored in memory under Failed Last Test.
- The Failure Records are stored.
^ Second consecutive drive cycle with a failure:
- The MIL is turned ON.
- A DTC is stored in memory under history.
- The Freeze Frame data is stored.
- The Failure Records are stored.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The control module turns OFF the Malfunction Indicator Lamp (MIL) after the third consecutive trip the diagnostic has run and passed.
^ The history DTC will clear if the fault conditions have not been detected for 40 warm-up cycles.
^ A scan tool can be used to clear DTC information.

TEST DESCRIPTION

Steps 1-11:

Steps 12-16:

The numbers below refer to the step numbers on the diagnostic table.
2. When the system is operating correctly the HO2S voltage should toggle above and below the specified values.
5. If the HO2S low signal circuit is shorted to ground the HO2S voltage will be less than 400 mV when the HO2S high signal circuit is jumped to ground.
6. The specified value is what is measured on a correctly operating system.
7. The specified value is what is measured on a correctly operating system.