P1134

CIRCUIT DESCRIPTION
The Powertrain Control Module (PCM) continuously monitors the Heated Oxygen Sensor (HO2S) activity. The PCM counts the number of times that the HO2S responds by switching from a rich state to a lean state. Next, the PCM adds the amount of time the HO2S look to complete all transitions during the 100-second test period. With this information, an average time for all transitions can be determined. The PCM then divides the rich-to-lean average by the lean-to-rich average to obtain a ratio. If the HO2S transition time ratio is not within range, this DTC will set. The setting of this DTC indicates that the oxygen sensor is not responding as expected, to changes in exhaust oxygen content.

CONDITIONS FOR RUNNING THE DTC
^ DTCs P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0125, P0128, P0201-P0206, P0300, P0410, P0440, P0442, P0443, P0446, P0449, or 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 550 RPM and 3000 RPM.
^ The engine is running in Closed Loop.

CONDITIONS FOR SETTING THE DTC
^ The above conditions present for a 100-second monitoring period.
^ The ratio of average response times is not between 4.5 and 0.5.

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 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
The numbers below refer to the step numbers on the diagnostic table.
4. This step checks for conditions which may cause the DTC to set with a good heated oxygen sensor. Correct any of the described conditions if present.
7. Before replacing the HO2S, check for silicon contamination.

Steps 1-4:

Steps 5-12:

HO2S TRANSITION TIME RATIO SENSOR 1