Zitat:The powertrain control module (PCM) supplies a bias voltage of approximately 450 mV on the heated oxygen sensor (HO2S) high and low signal circuits. When you turn the ignition ON, the battery voltage is supplied to the HO2S heater. As the heater reaches the operating temperature, the HO2S voltage responds by changing from a bias voltage range to the normal operation. Typically, as the HO2S reaches the operating temperature, the HO2S voltage goes from a bias voltage to a voltage below 300 mV. Depending on the exhaust gas content, the HO2S voltage can go above 450 mV.

The PCM runs the heater test only on a cold start, depending on the cumulative air flow, and only once an ignition cycle. When you start the engine, the PCM monitors the HO2S voltage. If the HO2S voltage goes above or below the bias range threshold, the PCM determines how much time passed. If the PCM detects that the process took too much time for the HO2S to enter into normal operating range, a DTC sets. The time the process takes the HO2S to reach the operating temperature is based on the amount of air that flows into the engine.

Zitat:Conditions for Running the DTC
• DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0131, P0132, P0134, P0137, P0138, P0140, P0151, P0152, P0154, P0157, P0158, P0160, P0200, P0300, P0410, P0440, P0442, P0446, P0452, P0453, P1120, P1125, P1220, P1221, P1221, P1258, P1415, P1416, P1441, P1514, P1515, P1516, P1517, or P1518 are not set.

• The intake air temperature (IAT) and the engine coolant temperature (ECT) are less than 50°C (122°F) and are within 8°C (14.5°F) of each other at engine start-up.

• The ignition 1 signal is between 9-18 volts.

• The secondary air injection (AIR) and the catalyst diagnostics are not active.

• The scan tool is disconnected.

• The mass air flow (MAF) is less than 18 g/s.

Zitat:Conditions for Setting the DTC
The HO2S voltage remains between 300-600 mV for a predetermined amount of time, depending on the engine coolant temperature and the air flow