P0150
CIRCUIT DESCRIPTIONThe Heated Oxygen Sensor (HO2S) is a sensor used to detect oxygen-content in the exhaust. The Powertrain Control Module (PCM) supplies the sensor with a signal circuit and a ground circuit. The PCM supplies a bias voltage between the circuits. The sensor varies the voltage based on the oxygen content in the exhaust. When the exhaust stream is lean, indicating more oxygen, the sensor produces a low voltage signal. When the exhaust stream is rich, indicating less oxygen, the sensor produces a high voltage signal. The PCM monitors the HO2S signal during Closed Loop. In order to correct for rich or lean conditions, the PCM adjusts the injector pulse width. This Diagnostic Trouble Code (DTC) indicates that the signal frequency of the HO2S indicates an active sensor, or Closed Loop, but the amplitude, or voltage, of the signal remains within an incorrect range.
CONDITIONS FOR RUNNING THE DTC
^ DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0117, P0118, P0121, P0122, P0123, P0125, P0131 or P0154, P0201-P0208, P1106, P1107, P1115, P1121, P1122, P1133 or P1153, P1134 or P1154 are not set.
^ The engine has been running more than 120 seconds.
^ The system voltage is between 10-18 volts.
^ The predicted O2 heater temperature is more than 600°C (1112°F).
^ The Engine Coolant Temperature (ECT) is more than 75°C (167°F).
^ The traction control is not active.
^ The catalyst test is not active.
^ The engine speed is between 500-5,000 RPM.
^ The Mass Air Flow (MAF) is between 3-30 g/s.
^ The Closed Loop fuel control is enabled.
^ The conditions above exist for 5 seconds.
CONDITIONS FOR SETTING THE DTC
^ The vehicle is in Closed Loop fuel control, based on HO2S voltages switching from below 350 mV to above 500 mV.
^ The PCM monitors the HO2S voltages for 120 seconds.
^ During the 120-second monitoring period, the voltage remains within 350 mV and 500 mV for approximately 16 seconds.
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 problem is intermittent, refer to Intermittent Conditions. Intermittent Conditions
TEST
