Avenger L4-2.0L DOHC (1995)
Oxygen Sensor: Description and Operation
Downstream O2 Sensor Heater Failure
NAME OF CODE:
Downstream O2S Heater Failure
WHEN MONITORED:
With the ignition key OFF, after the engine cools down.
SET CONDITION:
No sensor output signal is received when the PCM powers up the sensor heater.
THEORY OF OPERATION:
The downstream oxygen sensor is a voltage generating device. The PCM receives exhaust gas information from this O2 sensor. The sensor detects
exhaust gas content by a galvanic reaction within the sensor that produces a voltage. After measuring the amount of oxygen in the exhaust gases,
the downstream oxygen sensor tells the PCM how well the catalytic converter is oxidizing HC and CO components and reducing NOx components
in the engine exhaust gas. This O2 sensor serves as an indicator of oxygen content. The heater element helps the O2 sensor quickly reach a normal
and steady operating temperature, which is required for proper emission control.
POSSIBLE CAUSES:
-
Open heater element circuit
-
O2 sensor failure
