P0134

Diagnostic Chart:

Schematic:

When the Oxygen Sensor (O2S) reaches approximately 318°C (600°F) it becomes an electrical source that responds to the oxygen content in the exhaust. The PCM produces a bias voltage of approximately 450 millivolts on the oxygen sensor circuit. When the sensor is cold its internal resistance is extremely high; therefore, the PCM recognizes the bias as an open circuit. As the sensor warms up, the internal resistance decreases. When the sensor reaches approximately 318°C (600°F), it starts producing a voltage based on the oxygen content in the exhaust stream. This voltage is used by the PCM to determine a rich or lean signal and adjust the fuel mixture accordingly.

DTC PARAMETERS
DTC P0134 will set if the O2S Sensor 1 voltage is inactive (not reading outside 399-499 mV) for 125 seconds when:
^ The engine has been running at least 30 seconds.
^ Engine coolant is greater than 70°C (158°F) for 20 seconds.
^ TP angle is between 8% and 56%.
^ Air flow is greater than 3 grams per second for 20 seconds.
^ DTCs P0105, P0107, P0108, P0112, P0113, P0117, P0118, P0122, P0123, P0171, P0201, P0202, P0203, P0204, P0300, P0301, P0302, P0303, P0304, P0336, P0440, P0442, P0446, P0506, P0507, P0601, P0602 or P1441 are not set.

IMPORTANT: The O2S signal is continuously checked once the above conditions are met.

DIAGNOSTIC AIDS
Normal Scan tool readings in closed loop will show the oxygen sensor voltage varying between 150 mV and 850 mV