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 took 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
DTC P0101, DTC P0102, DTC P0103, DTC P0107, DTC P0108, DTC P0112, DTC P0113, DTC P0117, DTC P0118, DTC P0121, DTC P0122, DTC P0123, DTC P0125, DTC P0128, DTC P0201-P0206, DTC P0300, DTC P0410, DTC P0440, DTC P0442, DTC P0443, DTC P0446, DTC P0449, or DTC P1441 are not set.

CONDITIONS FOR SETTING THE DTC
^ The PCM detects the HO2S transition time ratio is less than 0.6, or more than 3.3.
^ The conditions are present for 2 minutes after closed loop enable.

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.
^ Use a scan tool in order to clear the MIL and the DTC.

DIAGNOSTIC AIDS
If the condition is intermittent, refer to Intermittent Conditions. Intermittent Conditions

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.
14. The new PCM must be programmed.