P0150
CIRCUIT DESCRIPTIONThe heated oxygen sensor (HO2S) is a sensor used to detect the 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 (more oxygen), the sensor produces a low voltage signal. When the exhaust stream is rich (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 DTC indicates that the signal frequency of the HO2S indicates an active sensor (Closed Loop), but the amplitude (voltage) of the signal remains within an incorrect range.
CONDITIONS FOR RUNNING THE DTC
^ DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0116, P0117, P0118, P0121, P0122, P0123, P0125, P0131, P0132, P0133, P0134, P0151, P0152, P0153, P0154, P0201-P0208, P1133, P1134, P1153, or P1154 are not set.
^ The coolant temperature is more than 75°C (176°F).
^ The engine is running for 120 seconds (2 minutes).
^ The system voltage is between 10-18 volts.
^ The predicted oxygen sensor (O2) heater temperature is 600°C (1,112°F).
^ The traction control is inactive.
^ The Catalyst Protection Mode is inactive.
^ The engine speed is between 500-5,000 RPM.
^ The mass air flow (MAF) is between 3-30 g/s.
^ All conditions above are met for 5 seconds.
^ The Closed Loop fuel control is enabled.
CONDITIONS FOR SETTING THE DTC
^ The vehicle is in Closed Loop fuel control, based on the HO2S voltages switching from below 350 mV to above 500 mV.
^ The PCM monitors the HO2S voltages for 120 seconds (2 minutes).
^ During the 120 second monitoring period, the voltage remains within 350-500 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.
^ Clear the MIL and the DTC with a scan tool.
DIAGNOSTIC AIDS
If the problem is intermittent, refer to Intermittent Conditions. Intermittent Conditions
TEST
